Chapter 39 / Endodontic Therapy for Primary Teeth / 1415 layer and no more bleeding. The teeth received a A study by Liu,129 which was conducted similarly to periapical radiograph prior to extraction and were his previously published case report, using an extracted at 28 or 90 days. The teeth were evaluated Nd:YAG laser with follow-up for up to 64 months radiographically and histologically. These researchers demonstrated a 97% clinical success rate and a 94.1% concluded that on the basis of symptomatic, clinical, radiographic success rate for the laser group that was radiographic, and histological findings, the CO2 laser compared to the 85.5% clinical success rate and a compares favorably to formocresol pulpotomies. 78.3% radiographic success rate for the formocresol A study was performed comparing a conventional control group. formocresol–ZOE pulpotomy with a diode laser- Odabas et al.130 performed a clinical, radiographic, MTA pulpotomy. In this study, the teeth were and histological study of Nd:YAG laser pulpotomies studied clinically and radiographically for a period compared to formocresol pulpotomies on 42 primary of up to 15.7 months. The researchers concluded teeth studied for a period of up to 12 months. This that the laser-MTA pulpotomy showed slightly study was conducted nearly identically to the previous reduced radiographic success rates compared to the studies. The laser group had a clinical success rate of formocresol–ZOE pulpotomy, but the results were 85.71%, and a radiographic success rate of 71.42%, at not statistically significant. They recommended that 9 and 12 months. The formocresol group had a clin- a larger sample with a longer follow-up was needed ical success rate of 90.47% and a radiographic success to consider the laser-MTA as an alternative to the rate of 90.47% at 9 and 12 months. These researchers formocresol–ZOE pulpotomy.127 conclude that the Nd:YAG laser may be considered as In a study by Huth et al.,128 four pulpotomy techni- an alternative to formocresol for pulpotomies for ques were compared: calcium hydroxide, Er:YAG, primary teeth. dilute formocresol, and ferric sulfate on a sample of As lasers become more commonplace in dentistry, 200 primary molars treated and followed for up to 24 dentists who own a laser now have a body of research months. The teeth were anesthetized and isolated with literature to justify the use of the laser to perform a rubber dam, and the caries was excavated and the pulpotomies for children in their practices. roof of each pulp chamber removed with a diamond bur. The coronal pulp was removed with a slow-speed round bur and a spoon excavator. Hemostasis was Ferric Sulfate obtained by placing wet cotton pellets with slight pres- sure in the chamber for 5 minutes. Formocresol-medi- The use of ferric sulfate as a primary tooth pulpotomy cated cotton pellets were applied to the pulp for 5 min- medicament begins to appear in the literature in the utes in the control group. In the laser group, the teeth late 1980s when Landau and Johnson131 published an were treated with an Er:YAG laser set at 2 Hz and abstract describing the use of ferric sulfate as a pulp 180 mJ per pulses without water cooling. The mean medicament in monkey’s teeth. The sample size was number of laser pulses per tooth was 31.5 ± 5.9. In the small and followed for only 60 days. They noted calcium hydroxide group, the teeth were dressed with secondary dentin formation and partial dentin brid- aqueous calcium hydroxide and covered with calcium ging. They also described ferric sulfate as a ‘‘promis- hydroxide cement. In the last group, the teeth were ing medicament for teeth indicated for pulpotomies.’’ treated with cotton pellets wetted with ferric sulfate for Subsequently, Fei et al.132 presented the first clinical 15 seconds. All of the teeth received an IRM base, study of ferric sulfate as a pulpotomy medicament for followed by a glass ionomer cement and a stainless primary teeth. In this study, 29 primary molars steel crown, or a composite resin. The teeth were received ferric sulfate pulpotomies and 27 received followed clinically and radiographically for up to 24 1:5 Buckley’s formocresol pulpotomies. Both groups months. After 24 months, the total (combined clinical received a ZOE base and were followed over 12 and radiographic success rates) and clinical success rate months. Criteria for clinical success included no symp- percentages (in parenthesis) were as follows: formocre- toms of pain, no tenderness to percussion, no swelling sol 85 (96%), laser 78 (93%), calcium hydroxide 53 or fistula, and no pathological mobility. Criteria for (87%), and ferric sulfate 86 (100%). The authors con- radiographic success included normal periodontal liga- cluded that calcium hydroxide was significantly less ment space, no pathological internal or external resorp- effective than formocresol. They also pointed out that tion, and no furcal or apical radiolucency. Results of an increased sample size would be necessary before it the study showed that after 1 year, 28 of 29 of the ferric could be definitively said that this laser technique or sulfate-treated teeth were considered successful while ferric sulfate was equal to, or better, than formocresol. only 21 of 27 of the formocresol-treated teeth were 1416 / Endodontics considered successful. Combined overall success rates formocresol–ZOE produced the least inflammation, were 96.6% for the ferric sulfate group and 77.8% for the use of polycarboxylate cement as a substitute for the formocresol group. They raised some interesting ZOE did not improve the pulpal response, and sig- points in their discussion. The use of ZOE as a base for nificant differences were not found regarding the formocresol pulpotomies is standard for this proce- pulpal inflammation between ZOE and polycarbox- dure. A ZOE base is also paired with ferric sulfate in ylate cements. order to standardize the two pulpotomy treatments. Fuks et al.134 studied ferric sulfate and dilute for- The authors suggested that ZOE is appropriate for mocresol pulpotomies in baboon teeth. Both medica- formocresol because the pulp tissue is somewhat fixed ments produced similar degrees of pulpal inflamma- from formocresol and would not react with the slightly tion and dentin bridging. Sixty percent of the teeth irritating eugenol. Because ferric sulfate is not a tissue had normal pulps and the remaining 40% had severe fixative, and probably leaves the tissue in a more vital inflammation. They recommended more clinical state, using ZOE as a base introduces an irritant that study of ferric sulfate. A number of clinical studies may contribute to failure. They suggested that it would comparing ferric sulfate and formocresol pulpo- be advisable to continue to study ferric sulfate as a tomies have been performed. In 1997, Fuks et al.135 primary tooth pulp medicament for longer periods of performed dilute formocresol and ferric sulfate pul- time and with more inert base materials. potomies and evaluated the teeth for up to 34 Additional animal studies on rat and baboon teeth months. They concluded that dilute formocresol have been performed to assess histologically the pul- and 15.5% ferric sulfate have similar success rates. pal healing response after pulpotomy with ferric sul- Smith et al.136 performed a retrospective study of fate and dilute formocresol. In her study using rats, clinical and radiographic data from the charts of Cotes133 had four test groups pairing ferric sulfate patients who received ferric sulfate pulpotomies and and dilute formocresol each with ZOE and polycar- ZOE base. They followed 242 teeth for 4 to 57 boxylate cements. She demonstrated that in the months (mean, 19 months). Their clinical success coronal third of the teeth tested, there was necrosis rate was 99% and the radiographic success rate was for all groups tested. In the middle third, there 74% to 80%. The longer the teeth were followed, was a lesser degree of inflammation for the dilute the more failures were noted radiographically. The formocresol–ZOE and ferric sulfate–polycarboxylate most common pathological radiographic observa- groups. In the apical third, the dilute formocresol–ZOE tions were calcific metamorphosis and internal group showed the least inflammation. In addition, resorption (Figure 11). Ninety percent of the teeth reparative dentin formation was noted in the apical survived after 3 years. They concluded that ferric third of the pulp in the ferric sulfate–ZOE group sulfate has a success rate similar to dilute formocre- while it was not found in the other groups. Conclu- sol. In addition, if the radiographic changes are sepa- sions from this study include the following: dilute rated into dental and osseous categories, and the

A B C

Figure 11 A, Radiograph showing internal resorption in a primary molar after ferric sulfate pulpotomy. B, Resorption resulted in perforation (arrow). C, Perforated area resulting from the resorptive process (arrow). Chapter 39 / Endodontic Therapy for Primary Teeth / 1417 dental changes (internal resorption and calcific A study involving rat first molars demonstrated metamorphosis) are reclassified as acceptable varia- that after 2 weeks the treated teeth responded well to tions of success, then the radiographic success rate MTA and were attempting to form dentinal bridges. would be 84% to 92%. The only radiographic changes In the 4-week samples, dentin bridges were comple- that would be classified as failures were interradicu- tely formed at the pulp–MTA interface and the pulps lar or periapical bone destruction and external appeared normal.143 In the dog study, the researchers resorption. These investigators also suggest that tested white and gray MTA as well as regular and since the goal is to keep the pulpotomized tooth white Portland cements as pulpotomy medicaments. asymptomatic until exfoliation, some degree of den- Seventy-six teeth from mongrel dogs received pulpot- tal changes is acceptable as long as it does not cause omy treatments. The teeth were evaluated after 120 pain or any symptoms. days and all four of the materials were found to have Additional clinical and retrospective studies and similar results. The pulps healed with dentin bridges one evidence-based assessment conclude that ferric that completely closed the pulpotomy access prepara- sulfate and dilute formocresol have similar clinical tions and the pulps appeared normal. The researchers and radiographic rates of success.137–139 Vargas140 concluded that both MTA and Portland cement were demonstrated that both ferric sulfate and formocresol good pulp capping agents, and they further suggested pulpotomies can cause early exfoliation of the pulpo- that Portland cement has the potential to be used as a tomized teeth with the subsequent need of space less expensive material in endodontics.144 They did maintenance until the premolar erupts. not address the fact that Portland cement is not While most of the published studies on ferric sul- approved for human use. fate compare it to formocresol pulpotomy, Casas A number of human studies using MTA as a pulp et al.141,142 took a different path, comparing it instead capping material in primary teeth have demonstrated to primary tooth root canal therapy (pulpectomy). that MTA performs as well or better than formocresol. Root canal therapy with a plain ZOE obturation and Teeth in these studies were followed for periods of ferric sulfate pulpotomy were found to have similar 6 to 74 months. Pulp canal obliteration was a common success rates up to about 2 years, but past 2 years, the finding in teeth treated with MTA. Various authors root canal treatment had better success. They sug- conclude that MTA is a reasonable replacement for gested that complete obturation of the canal rather formocresol because of its high success rates and it lacks than the partial treatment of the pulp is the best the undesirable side effects of formocresol.145–150 Stu- treatment for pulpally involved primary teeth. They dies that tested both gray and white MTA concluded did concede that it will be difficult to get the pediatric that the gray formulation produces better results than dental community to change because of the relatively the white.146,150 While MTA has shown excellent results high success rates of pulpotomy, because this was the as a pulp capping agent for primary teeth pulpotomies, treatment they learned as a student or a resident, and the one factor that seems to keep it from becoming the because pulpotomy is a simple treatment and some new gold standard replacement for formocresol is the children are not cooperative enough to sit for a pul- cost of the material. Only time will tell if MTA will pectomy treatment (Figure 12). replace formocresol as the most commonly used pulp capping material for primary teeth.

Mineral Trioxide Aggregate Nonvital Pulp Therapy for Children MTA has only recently been recommended as a pulp In children, complete root canal treatment on primary capping agent in primary teeth. The first published teeth is often referred to as a pulpectomy procedure. clinical trials in primary teeth began in 2001 and in While the term pulpectomy only infers removal of the animal studies occurred in 2003 to 2004 in rat and dog pulp, this term in pediatric dentistry has come to mean teeth. removal of the caries and the inflamed or necrotic 1418 / Endodontics

A B C

D E F

Figure 12 Pulpotomy technique. A, Primary molar with large carious lesion. B, Caries removed and pulp exposed. C, Pulp tissue removed from the chamber. D, Pulp space being treated with ferric sulfate. E, After treatment with ferric sulfate. F, ZOE base has been placed.

pulp, cleaning and shaping the root canals, and obtura- procedure or if the tooth has only reversible pulpitis tion of the tooth with a resorbable root filling material. symptoms because they believe a complete obturation Pulpectomy is indicated when a tooth has irreversible of the canal is preferable to partial obturation whenever pulpitis or a necrotic pulp or when a tooth has been possible. A number of articles recommend pulpectomy treatment planned for a pulpotomy and excessive as a substitute for all pulpotomies.151–153 hemorrhage (hyperemia) is encountered at the time Pulpectomy procedures for primary teeth must be done of treatment.1 Some pediatric dentists prefer pulpect- with a consideration for the subjacent succedaneous tooth omy procedure for primary anterior teeth even if the (Figure13).Itbeginswithprofoundpulpal tooth could be a candidate for only a pulpotomy anesthesia followed by placement of a rubber dam. Chapter 39 / Endodontic Therapy for Primary Teeth / 1419

Figure 13 Illustration shows the proximity of primary molar roots to Figure 14 Removal of the roof of the chamber and coronal pulp. subjacent succedaneous tooth. Courtesy of Dr. A.C. Goerig. Courtesy of Dr. A.C. Goerig.

All caries are removed with a slow-speed round bur a facial veneer preparation. Following pulpectomy, or a spoon excavator (Figure 14). From the point the tooth can be restored with a light composite resin of the pulp exposure, an access preparation is made in the pulp chamber to veneer the facial surface of the by connecting the pulp horns with the bur. This tooth to mask the discoloration. creates the outline of the access preparation. The To remove the radicular pulp in anterior teeth, a roof of the chamber and the coronal pulp are good technique is to insert two very small files (size 10 removed. The access preparation is refined to make or 15) on either side of the pulp and twist the files sure that access to all of the canals is possible. removing the whole pulp in one motion. In posterior There should be slight flaring of the access to allow teeth, a barbed broach is used. The canals can be for ease of insertion of the files. irrigated with sodium hypochlorite or sterile saline. It In clinical situations where a primary incisor has no will be necessary to irrigate the canal several times caries but has been affected by dental trauma that throughout the procedure. caused a gray discoloration, the access can be per- Files are measured 1 mm short of the apex by formed from the facial. It is very similar to a lingual comparing them to the length of the tooth on a radio- access, as it connects the pulp horns and makes a graph. This gives a preliminary working length. It is triangular-shaped preparation that is combined with important to avoid extending instruments into the 1420 / Endodontics

Figure 15 Pulpectomy treatment—file inserted into the canal. Courtesy Figure 16 Pulpectomy treatment—obturation of the canals with zinc of Dr. A.C. Goerig. oxide–eugenol (ZOE) placed with an instrument. Courtesy of Dr. A.C. Goerig. apical area. The file is inserted into the canal and with into the canal with a rotary paste filler (Figure 17). It tactile sense felt for an apical stop (Figure 15). An is very important that commercially prepared zinc alternative method is to insert a medium or a large- oxide cements, with reinforcing fibers, not be used, sized file (medium for molars and larger files for ante- as these reinforced cements are not well resorbed. The rior teeth) into the canal of the tooth and feel for an unreinforced ZOE is mixed into a thick paste. Large apical stop. This measurement is then compared to the rotary spirals work well for maxillary anterior teeth, radiograph. After the correct length is established, and small spirals are suited for molars and mandibu- smaller files are set to this length. Studies have shown lar incisors. The rotary spiral is inserted into the canal that electronic apex locators can accurately be used while it is not turning and is used to search for the when treating primary teeth.154,155 Excessive cleaning apical stop. The paste filler is then slightly removed so and shaping of the canal should be avoided since that that it is short of the apical stop and the handpiece is can damage the tooth and lead to extraction caused by revolved slowly. The dental assistant places the ZOE perforation in the furcation or the lateral wall of a on the spatula next to the revolving paste filler that canal. The purpose of filing is to remove the pulp tissue pulls the ZOE off the spatula and introduces the and make room for the root canal filling material. After cement into the canal. The speed of the handpiece the canals are cleaned, they should be irrigated again can be adjusted to cause the ZOE to completely fill the and dried with appropriately sized sterile paper points. canal. When the dentist believes that the canal is There are a number of choices of root canal filling completely filled, the paste filler is removed while still materials that can be used for primary teeth, and each rotating. If the paste filler is removed after it has of these materials has an appropriate obturation tech- stopped, it will pull the ZOE from the canal. nique (Figure 16). Unreinforced zinc oxide and euge- A periapical radiograph is then exposed to deter- nol is a very common material and is easily placed mine the adequacy of the root canal filling. If the Chapter 39 / Endodontic Therapy for Primary Teeth / 1421

Figure 17 Examples of rotary paste fillers. canal is not completely filled, the paste filler is rein- to be resorbed uneventfully although it is better to troduced into the canal to achieve a better obtur- have an underfill than an overfill. The tooth is then ation. Small amounts of ZOE overfill can be expected restored and monitored until it exfoliates21,22,151,156 (Figures 18 and 19). There have been many articles that quantify the success rate of pulpectomy and root canal treatments in primary teeth. In 1978, Jokinen et al.157 studied 1,304 pulpectomies and found that only 53% were successful. Success rates in the mandible and maxilla were nearly equal. This study is of historical interest, but it is difficult to use these results in judging today’s dental care because the technique was very different than the average pulpectomy that is per- formed today. Flaitz et al.158 followed 87 pulpectomies in primary incisors that were obturated with ZOE, with a drop of formocresol in the cement mixture, for a period of 37.4 months. They found a success rate of 84%. In a follow- up study of 62 patients over a period of 12 to 74 months, these same researchers demonstrated a success rate of 82.3% for primary molar pulpectomies with a ZOE filling material.159 Yacobi153 et al. performed ZOE pulpectomies on both primary incisors and molars on 51 children over a period of 12 months and found a success rate of 76% for the anterior teeth and a success rate of 84% for the posteriors. Payne et al.160 studied Figure 18 Pulpectomy treatment—tooth restored with a stainless steel primary 253 anterior and posterior primary teeth for up crown. Courtesy of Dr. A.C. Goerig. to 24 months. Their success rate for anterior teeth was 1422 / Endodontics

A B C

Figure 19 A, Primary molar with large caries lesion involving the pulp. B, Radiograph taken after pulpectomy and root canal filling. C, Evaluation 1 year later.

82.8% and 90.3% for posterior teeth. Coll et al.161 logical evaluations of both calcium hydroxide and followed 65 ZOE pulpectomies for a period of 90.8 ZOE found that the calcium hydroxide specimens months. The overall success rate was 77.7%. Two addi- were more successful in all areas. Another study by tional studies provide success rates of 76% and 78.5% Mani et al.173 compared 60 ZOE and calcium hydro- for ZOE pulpectomies.162,163 xide pulpectomies. Combined clinical and radio- Rifkin164 used Kri Paste (a mixture of p-chlorophenol, graphic success rates were 83.3% for the ZOE group camphor, menthol, and iodoform) to treat 45 primary and 86.7% for the calcium hydroxide group. Ozalp teeth. The teeth were treated in either 1 or 2 appointments et al.174 found a success rate of 80 to 90% for depending on the symptoms. After 1 year, 42 of the 45 pulpectomies that were obturated with calcium teeth were asymptomatic. Garcia-Godoy165 treated 55 hydroxide. primary teeth with multiple appointment pulpectomies, Vitapex (NeoDental International, Inc., Federal Way, obturatedwithKriPaste,andfollowedforupto2years. WA) is a commercially prepared calcium hydroxide and There were no clinical or radiographic signs or symptoms iodoform mixture that is prepackaged in syringes speci- in 95.6% of the teeth. Coll et al.166 compared 41 pulpec- fically for pulpectomies. It has been tested by a number tomies on primary teeth with pulp necrosis that were of researchers. A case report by Nurko et al.175 recom- obturated with Kri Paste over a period of up to 6 years 10 mends it as an excellent material for pulpectomies in months. The teeth had a success rate of over 80%. An spiteofsomeproblemswithresorptionofthematerial. additionalstudybyColl167 confirmed this success rate. Three additional studies document the use of Vitapex Another study by Reyes and Reina168 with a similar with follow-up of up to 22 months; the success rates technique documented a 100% success rate. Thomas approached 100%.162,174,176 et al.169 studied 36 primary teeth for 3 months after One in vitro study by Tchaou et al.177 compared pulpectomies and obturated with iodoform paste. various dental materials used in pulpectomies for They found a success rate of 94.4%. Holan and primary teeth for bacterial inhibition. They compared Fuks170 compared ZOE- and Kri Paste-filled pulpec- calcium hydroxide mixed with camphorated p-chlor- tomies on primary molars evaluated for periods up to ophenol (Ca(OH)2 +CPC),calciumhydroxide 48 months. They demonstrated a success rate of 84% mixedwithsterilewater(Ca(OH)2 +H2O), zinc for Kri Paste and 65% for ZOE. After a number of oxide mixed with CPC (ZnO + CPC), zinc oxide clinical studies using Kri Paste for pulpectomies, mixedwitheugenol(ZOE),ZOEmixedwithformo- Wright et al.171 performedaninvitroantimicrobial cresol (ZOE + FC), zinc oxide mixed with sterile and cytotoxic study of Kri Paste and ZOE. In this water (ZnO + H2O), ZOE mixed with chlorhexidine study, they found that ZOE had better antimicrobial dihydrochloride (ZOE + CHX), Kri paste, Vitapex activity and that both materials had similar cytotoxi- paste, and Vaseline. They found that the materials city. could be divided into three groups. Category I with Hendry172 and his fellow researchers performed the strongest antibacterial effect included ZnO + pulpectomies using calcium hydroxide and plain CPC, Ca(OH)2 +CPC,andZOE+FC.CategoryII ZOE on mongrel dogs. They exposed the pulps of with a medium bacterial effect included ZOE + the dogs to produce inflamed pulps. The teeth were CHX, Kri, ZOE, and ZnO + H2O. Category III with later instrumented and obturated with either calcium no or minimal antibacterial effect included Vitapex, hydroxide or ZOE. Clinical, radiographic, and histo- Ca(OH)2 +H2O, and Vaseline. Chapter 39 / Endodontic Therapy for Primary Teeth / 1423

There are many articles that describe aspects of the teeth were then obturated with Vitapex. Radiographs pulpectomy technique and the instruments involved were evaluated for the presence of an overfill. In the in the procedure. Once a primary molar begins to test group, overfills were present in 16% of teeth. In resorb, from physiological resorption or from patho- the control group (no barrier), overfills were present sis, it can be difficult for the dentist to know if the in 42% of teeth. They suggest that resorbable collagen canals of the tooth can be properly instrumented or barriers can help prevent overfills. One problem that even to obtain a correct working length. Rimondini can be experienced with resorbable cements placed in and Baroni178 studied 80 primary molars in children 4 root canals of primary teeth is overretention of the to 12 years old, 75 of which were extracted because of material in the alveolus after exfoliation of the pri- pulpal involvement. The teeth were measured and the mary tooth (Figure 20). Studies by Sadrian and apices and areas of resorption were located. They Coll183 and Coll et al.166,167 have shown that ZOE found that roots that were longer than 10 mm were cement was retained in the alveolus in 49.4% to related to a curved root shape with no external 73.3% of the exfoliated teeth, and this material was resorption. Roots with length between 4 to 7 mm were still retained in 27.3% of the patients after 40.2 associated with advanced root resorption. Roots that months. Short-filled pulpectomies were significantly were shorter than 4 mm were associated with resorp- less likely to overretain ZOE.161 One of the two stu- tion and perforation of the furcation. They identified dies evaluated over 6,000 charts in a pediatric dentis- 4 mm as the limit of the length of a root that can be try private practice.183 Jerrell and Ronk184 presented a treated successfully. case study of the arrest of eruption of a permanent Barr et al.179 presented the use of rotary nickel–ti- premolar after ZOE material was extruded from the tanium files to prepare primary teeth for pulpectomy primary molar pulpectomy into the developing tooth treatment. Advantages of this technique include ease bud. Fortunately in the case of this particular patient, of removal of tissue and debris, flexible design allow- premolar extraction was a part of the patient’s ortho- ing access to canals, files prepare the canal in a funnel dontic treatment plan, so the tooth was extracted. It is shape to ease obturation, and the files are available in reassuring that studies have shown a low incidence of 21 mm length. Disadvantages of the use of these files enamel hypoplasia in succedaneous teeth when the include cost of the equipment (handpiece), increased primary teeth have been treated with pulpectomy cost of the files, and the time required to learn the techniques.161,166 technique. An in vitro study was performed on three pulpectomy filling devices: Lentulo spiral (Dentsply International), NaviTip (Ultradent Products, Inc., South Jordan, UT), and Vitapex syringe (NeoDental Educational Curricula and Attitudes International, Inc.). Seventy extracted primary teeth were prepared and mounted in acrylic blocks. The of Pediatric Dentists teeth were divided into three groups and pulpec- AstudybyAvran185 in 1987 surveyed pediatric den- tomies were done followed by obturation with three tistry residencies in Canada and a number of dental different methods. The specimens were radiographed schools worldwide. He found that in Canada among and evaluated and the conclusion was that the Navi- pediatric dental specialists, the preferred pulp med- Tip produced the best quality fill.180 Bawazir and icament for 50% of the respondents was 1:5 formo- Salama181 studied two methods of obturating root cresol and full-strength formocresol was preferred canals with Lentulo spiral paste fillers. One technique by 42.2%. In Canadian pediatric dental residency was with the Lentulo mounted on a slow-speed hand- programs, full-strength formocresol was preferred piece and the other method was with a handheld by 40.8% of respondents and 1:5 formocresol was Lentulo. They concluded that there was no difference preferred by 36%. Seventy percent of respondents in the two methods as far as the quality of the fill or in in Scandinavian dental schools preferred calcium the success of the obturation. hydroxide. This is not unexpected since much of Johnson et al.182 performed an in vitro study using the research on calcium hydroxide as a pulp medica- an apical resorbable collagen barrier to prevent over- ment has been done there. When respondents were fill of the canal. The apices of the teeth were coated asked if they were considering a change to another with wax and the teeth were embedded into acrylic. medicament, many said they would consider glutar- The canals were filed, rinsed, and dried. A resorbable aldehyde. collagen barrier was packed into some of the canals A second study was published by Primosch186 in and the remainder of the teeth served as controls. The 1997 based on a survey of the pediatric dental 1424 / Endodontics

A B

C D

Figure 20 A, Large caries on primary incisors at the time of diagnosis. B, Approximately 3 years after endodontic treatment. C, Five and half years after treatment, the primary tooth is retained and deflecting permanent successor. D, The primary incisor has been extracted. Radiograph shows retained zinc oxide–eugenol (ZOE) material. The right primary incisor was subsequently extracted. programs in the United States regarding curricula for interest in glutaraldehyde has decreased, interest and pulp therapy in children. Calcium hydroxide was the research on ferric sulfate has greatly increased. preferred base for pulp capping. Most schools taught In regard to pulpectomy procedure, 98% of US dental that after the first appointment of an indirect pulp schools were teaching hand instrumentation of canals, cap, it would be necessary to reenter the tooth only if with the majority of schools not recommending any enlar- the patient experienced symptoms. A 1:5 dilution of gement of the canal. The most commonly recommended formocresol was the most commonly (71.7%) recom- irrigants were sodium hypochlorite, sterile water or saline, mended medicament for pulpotomy procedure, and it and local anesthetic. Ninety percent of schools recom- was left in the tooth for 5 minutes (94.3%). ZOE was mended zinc oxide and eugenol as the preferred filling the most commonly recommended base (92.4%). It is for root canals. These two studies have now become out- interesting to note that while some practitioners were dated. So why include this information? These are only considering changing from formocresol to glutaralde- two journal articles that quantify what is being taught in hyde in Avram’s study in the 1980s, no US dental dental schools. It is important to realize that for- school included glutaraldehyde in the curriculum in mocresol has been advocated as a pulp medicament the 1997 study. Further, the Primosh’s study reported for a very long time, and it seems to be very that 2 of 53 dental schools in 1997 were teaching ferric entrenched in pediatric dental education. While it sulfate or 1:5 formocresol to their students. While may have a number of problems, no substitute has Chapter 39 / Endodontic Therapy for Primary Teeth / 1425 been overwhelmingly advocated to take its place. It 12. Aponte AJ, Hartsook JT, Crowley MC. Indirect pulp capping is certain that there is much room for research on success verified. ASDC J Dent Child 1966;33:164–6. new pulp medicaments to replace formocresol. 13. Sawusch RH. Direct and indirect pulp capping with two new products. J Am Dent Assoc 1982;104:459–62. 14. Nirschl RF, Avery DR. Evaluation of a new pulp capping Conclusion agent: a clinical investigation. [Special Issue A] J Dent Res Endodontic therapy, from pulp capping, pulpotomy 1980;March;59:362. or to pulpectomy, is an excellent procedure to prevent 15. Nirschl RF, Avery DR. 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Two-year out- cresol as pulpotomy agents in rat molar. Dent Traumatol come study of zinc oxide-eugenol root canal treatment for vital 2003;19:314–20. primary teeth. J Can Dent Assoc 1993;59(6):528–36. 144. Menezes R, Bramante CM, Letra A, et al. Histologic evalua- 161. Coll JA, Sadrian R. Predicting pulpectomy success and its tion of pulpotomies in dog using two types of mineral relationship to exfoliation and succedaneous dentition. trioxide aggregate and regular and white Portland cements Pediatr Dent 1996;18(1):57–63. 1430 / Endodontics

162. Mortazavi M, Mesbahi M. Comparison of zinc oxide and 174. Ozalp N, Saroglu I, Sonmez H. Evaluation of various root eugenol, and Vitapex for root canal treatment of necrotic canal filling materials in primary molar pulpectomies: an in teeth. Int J Paediatr Dent 2004;14(6):417–24. vivo study. Am J Dent 2005;18(6):347–50. 163. Primosch RE, Ahmadi A, Setzer B, Guelmann M. A retro- 175. Nurko C, Ranly DM, Garcia-Godoy F, Lakshmyya KN. spective assessment of zinc oxide–eugenol pulpectomies Resorption of a calcium hydroxide/iodoform (Vitapex) in in vital maxillary primary incisors successfully restored root canal therapy for primary teeth: a case report. Pediatr with composite resin crowns. Pediatr Dent 2005;27(6): Dent 2000;22(6):517–20. 470–7. 176. Nurco C, Garcia-Godoy F. Evaluation of a calcium hydro- 164. Rifkin A. A simple, effective, safe technique for the root xide/iodoform paste (Vitapex) in root canal therapy for canal treatment of abscessed primary teeth. J Dent Child primary teeth. J Clin Pediatr Dent 1999; 23(4):289–94. 1980;47(6):435–41. 177. Tchaou WS, Turng BF, Minah GE, Coll JA. In vitro inhibition of 165. Garcia-Godoy F. Evaluation of an iodoform paste in root bacteria from root canals of primaryteethbyvariousdental canal therapy for infected primary teeth. J Dent Child materials. Pediatr Dent 1995;17(5):351–5. 1987;54(1):30–4. 178. Rimondini L, Baroni C. Morphologic criteria for root canal 166. Coll JA, Josell S, Casper JS. Evaluation of a one-appointment treatment of primary molars undergoing resorption. Endod formocresol pulpectomy technique for primary molars. Dent Traumatol 1995;11(3):136–41. Pediatr Dent 1985;7(2):123–9. 179. Barr ES, Kleier DJ, Barr NV. Use of nickel–titanium rotary 167. Coll JA, Josell S, Nassof S, et al. An evaluation of pulpal therapy files for root canal preparation in primary teeth. Pediatr in primary incisors. Pediatr Dent 1988;10(3):178–84. Dent. 1999;21(7):453–4. Also reprinted in Pediatr Dent 168. Reyes AD, Reina ES. Root canal treatment in necrotic pri- 2000;22(1):77–8. mary molars. J Pedod 1989;14(1):36–9. 180. Guelman M, McEachern M, Turner C. Pulpectomies in 169. Thomas AM, Chandra S, Chandra S, Pandey RK. Elimina- primary incisors using three delivery systems: an in vitro tion of infection in pulpectomized deciduous teeth: a short- study. J Clin Pediatr Dent 2004;28(4):323–6. term study using iodoform paste. J Endod 1994;20(5):233–5. 181. Bawazir OA, Salama FS. Clinical evaluation of root canal obtura- 170. Holan G, Fuks AB. A comparison of pulpectomies using tion methods in primary teeth. Pediatr Dent 2006;28(1):39–47. ZOE and Kri paste in primary molars: a retrospective study. 182. Johnson MS, Britto LR, Guelmann M. Impact of a biological Pediatr Dent 1993;15(6):403–7. barrier in pulpectomies of primary molars. Pediatr Dent 171. Wright KJ, Barbosa SV, Araki K, Spangberg LSW. In vitro 2006;28(6):506–10. antimicrobial and cytotoxic effects of Kri 1 paste and zinc 183. Sadrian R, Coll JA. A long-term follow-up on the retention oxide–eugenol used in primary tooth pulpectomies. Pediatr rate of zinc oxide eugenol filler after primary tooth pulpect- Dent 1994;16(2):102–6. omy. Pediatr Dent 1993;15(4):249–53. 172. Hendry JA, Jeansonne BG, Dummett CO, Burrell W. 184. Jerrell RG, Ronk SL. Developmental arrest of a succedaneous Comparison of calcium hydroxide and zinc oxide tooth following pulpectomy in a primary tooth. J Pedod eugenol pulpectomies in primary teeth of dogs. Oral Surg 1982;6(4):337–42. Oral Med Oral Pathol Oral Radiol Endod 1982; 54(4):445–51. 185. Avran DC, Pulver F. Pulpotomy medicaments for vital pri- mary teeth ASCD J Dent Child 1989;56(6):426–34. 173. Mani SA, Chawla HS, Tewari A, Goyal A. Evaluation of calcium hydroxide and zinc oxide eugenol as root canal 186. Primosch RE, Glomb TA, Jerrell RG. Primary tooth pulp filling materials in primary teeth. J Dent Child 2000; therapy as taught in predoctoral pediatric dental programs 67(2):142–7. in the United States. Pediatr Dent 1997;19(2):118–22. CHAPTER 40

RESTORATION OF ENDODONTICALLY TREATED TEETH

CHARLES J. GOODACRE,NADIM Z. BABA

Various methods of restoring pulpless teeth have been used for 18 years. Subsequently, pivot crowns were reported for more than 200 years. In 1747, Pierre fabricated using wood/metal combinations and then Fauchard1 described the process by which roots of more durable all-metal pivots were used. Metal pivot maxillary anterior teeth were used for the restoration retention was achieved by various means such as of single teeth and the replacement of multiple teeth threads, pins, surface roughening, and split designs that (Figure 1). Posts were fabricated of gold or silver and provided mechanical spring retention.2 held in the root canal space with a heat-softened Unfortunately, adequate cements were not available adhesive called ‘‘mastic.’’1,2 The longevity of restora- to these early practitioners, cements that would have tions made using this technique was attested to by enhanced post retention and decreased abrasion of Fauchard: ‘‘Teeth and artificial dentures, fastened the root caused by movement of metal posts within with posts and gold wire, hold better than all others. the canal. One of the best representations of a pivoted They sometimes last fifteen to twenty years and even tooth appears in Dental Physiology and Surgery, writ- more without displacement. Common thread and ten by Sir John Tomes in 1849 (Figure 2).5 Tomes’ post silk, used ordinarily to attach all kinds of teeth or length and diameter conformed closely to today’s prin- artificial pieces, do not last long.’’1 ciples in fabricating posts. The replacement crowns were made from bone, Endodontic therapy, by these dental pioneers, emb- ivory, animal teeth, and sound natural tooth crowns. raced only minimal efforts to clean, shape, and obturate Gradually the use of these natural substances declined, the canal. Frequent use of the wooden posts in empty to be slowly replaced by porcelain. A pivot (what is canals led to repeated episodes of swelling and pain. Woo- today termed a post) was used to retain the artificial den posts, however, did allow the escape of the so-called porcelain crown into a root canal and the crown–post ‘‘morbid humors.’’ A groove in the post or the root canal combination was termed a ‘‘pivot crown.’’ Porcelain provided a pathway for continual suppuration from the pivot crowns were described in the early 1800s by a periradicular tissues.1 well-known dentist of Paris, Dubois de Chemant.2 Although many of the restorative techniques used Pivoting (posting) of artificial crowns to natural roots today had their inception in the 1800s and early became the most common method of replacing arti- 1900s, proper endodontic treatment was negle- ficial teeth and was reported as the ‘‘best that can be cted until years later. Today, both endodontic and employed’’ by Chapin Harris in The Dental Art in prosthodontic aspects of treatment have advanced 1839.3 significantly, new materials and techniques have been Early pivot crowns in the United States used sea- developed, and a substantial body of scientific knowl- soned wood (white hickory) pivots.4 The pivot was edge is available upon which to base clinical treatment adapted to the inside of an all-ceramic crown and also decisions. into the root canal space. Moisture would swell the The purpose of this chapter is to answer questions wood and retain the pivot in place.2 Surprisingly, frequently encountered when dental treatment involves Prothero2 reported removing two central incisor endodontically treated teeth and to describe the tech- crowns with wooden pivots that had been successfully niques commonly employed when restoring these

1431 1432 / Endodontics

teeth. Whenever possible, the answers and discussion will be supported by scientific evidence. Conflicting results will be presented to provide a comprehensive understanding of the available evidence.

Should Crowns Be Placed on Endodontically Treated Teeth? A retrospective study6 of 1,273 teeth endodonti- cally treated 1 to 25 years previously compared the clinical success of anterior and posterior teeth. Endodontically treated teeth with restorations that encompassed the tooth (onlays, partial or complete coverage metal crowns, and metal ceramic crowns) were compared with endodontically treated teeth with no coronal coverage restorations. It was deter- mined that coronal coverage crowns did not sig- nificantly improve the success of endodontically treated anterior teeth. This finding supports the Figure 1 Early attempts to restore single or multiple units. A, ‘‘Pivot use of a conservative restoration such as an etched tooth’’ consisting of crown, post, and assembled unit. B, Six-unit ante- rior fixed partial dental prosthesis ‘‘pivoted’’ in lateral incisors with resin restoration in the access opening of otherwise canines cantilevered. Crowns were fashioned from a diversity of materi- intact or minimally restored anterior teeth. Crowns als. Human, hippopotamus, sea horse, and ox teeth were used, as well are indicated only on endodontically treated ante- as ivory and oxen leg bones. Posts were usually made from precious rior teeth when they are structurally weakened by metals and fastened to the crown and root by using a heated sticky thepresenceoflargeand/ormultiplecoronal ‘‘mastic’’ prepared by gum, lac, turpentine, and white coral powder. restorations or they require significant form/color changesthatcannotbeeffected by bleaching, resin bonding, or porcelain laminate veneers. Scurria et al.7 collected data from 30 insurance carriers in 45 states regarding the procedures 654 general dentists performed on endodontically treated teeth. The data indicated that 67% of endodontically treated anterior teeth were restored without a crown, supporting the concept that many anterior teeth are being satisfactorily restored without the use of a crown. When endodontically treated posterior teeth (with and without coronal coverage restorations) were com- pared, a significant increase in the clinical success was noted when cuspal coverage crowns were placed on maxillary and mandibular molars and premolars.6 In a study of 116 failed and extracted endodontically trea- ted teeth, Vire8 reported that teeth restored with crowns had greater longevity than uncrowned teeth. A strong association was found between crown place- Figure 2 Principles used today in selecting post length and diameter ment and the survival of endodontically treated teeth. were understood and taught by early practitioners during mid-1800s. If long-term tooth survival is the primary goal, placing Chapter 40 / Restoration of Endodontically Treated Teeth / 1433

A B

Figure 3 A, Occlusal view showing the fracture of the buccal cusp of an endodontically treated mandibular left first molar. B, Extracted tooth showing the fracture extending down both roots. a crown on an endodontically treated posterior tooth completely intact except for a conservative access enhances survival (Figure 3).9 Therefore, restorations opening, they could be restored successfully by using that encompass the cusps should be used on poster- composite resin restorations. ior teeth that have intercuspation with opposing Multiple clinical studies of fixed partial dentures, teeth and thereby receive occlusal forces that push many with long spans and cantilevers, have deter- the cusps apart. The previously discussed insurance mined that endodontically treated abutments failed data7 indicated that 37 to 40% of posterior endo- more often than vital teeth due to tooth fracture,13–17 dontically treated teeth were restored by practitioners supporting the greater fragility of endodontically trea- without a crown, a method of treatment not sup- ted teeth and the need to design restorations that ported by the long-term clinical prognosis of poster- reduce the potential for both crown and root fractures ior endodontically treated teeth that do not have when extensive fixed prosthodontic treatment is cusp-encompassing crowns. There are, however, cer- required. tain posterior teeth (not as high as 40%) that do not Gutmann18 reviewed the literature and presented an have substantive occlusal intercuspation or have an overview of several articles that identify what happens occlusal form that precludes intercuspation of a nat- when teeth are endodontically treated. These articles ure that attempts to separate the cusps (such as provide background information important to an mandibular first premolars with small, poorly devel- understanding of why coronal coverage crowns help oped lingual cusps). When teeth are intact or mini- prevent fractures of posterior teeth. Endodontically mally restored (small MO or DO restorations), they treated dog teeth have been found to have 9% less would be reasonable candidates for restoration of moisture than vital teeth.19 In addition, it was found only the access opening without the use of a coronal that dehydration increases stiffness and decreases the coverage crown.10 flexibility in teeth. However, dehydration by itself does In contrast to the above recommendations, a 3-year not account for the physical property changes in den- clinical study by Mannocci et al.11 evaluated the clin- tin.20 Also, with aging, greater amounts of peritubular ical success rate of endodontically treated premolars dentin are formed, which decreases the amount of restored with a post and direct composite resin organic materials that may contain moisture. It has restorations with and without complete crown cover- been shown that endodontic procedures reduce tooth age. They found that both had a similar success rate. stiffness by 5%, attributed primarily to the access open- Nagasiri et al.,12 in a retrospective cohort study, indi- ing.21 Tidmarsh22 described the structure of an intact cated that when endodontically treated molars are tooth that permits deformation when loaded occlusally 1434 / Endodontics and elastic recovery after removal of the load. The direct With Pulpless Teeth, Do Posts Improve relationship between tooth structure removed during tooth preparation and tooth deformation under load Long-Term Clinical Prognosis has been described.23 Dentin from endodontically trea- or Enhance Strength? ted teeth has been shown to exhibit significantly lower shear strength and toughness when compared with vital Historically, the use of posts was based on the concept dentin.24 Rivera et al.25 stated that the effort required to that a post reinforces the tooth. fracture dentin may be less when teeth are endodonti- cally treated because of more immature (potentially LABORATORY DATA 27–37 weaker) collagen intermolecular cross-links. In a recent Virtually all laboratory studies have shown that study, it was found that collagen fibrils degraded placement of a post and core either fails to increase the over time in teeth with zinc phosphate-cemented posts. fracture resistance of endodontically treated extracted Acid demineralization can also occur from bacteria and teeth or decreases the fracture resistance of the tooth acid etching.26 when a force is applied via a mechanical testing machine. Lovdahl and Nicholls27 found that endodon- CONCLUSIONS tically treated maxillary central incisors were stronger Restorations that encompass the cusps of endodonti- when the natural crown was intact except for the access opening than when they were restored with cast posts cally treated posterior teeth have been found to 28 increase the clinical longevity of these teeth. There- and cores or pin-retained silver amalgams. Lu found fore, crowns should be placed on endodontically trea- that posts placed in intact endodontically treated cen- ted posterior teeth that have occlusal intercuspation tral incisors did not lead to an increase in the force required to fracture the tooth or in the position and with opposing teeth of the nature that places expan- 29 sive forces on the cusps. Since crowns do not enhance angulation of the fracture line. Pontius found that the clinical success of anterior endodontically treated maxillary incisors, without posts, resisted higher fail- ure loads than the other groups with posts and crowns. teeth, their use on relatively sound teeth should be 30 limited to situations where esthetic and functional Gluskin found that mandibular incisors with intact requirements cannot be adequately achieved by other natural crowns exhibited greater resistance to trans- more conservative restorations (Figure 4). verse loads compared with teeth with posts and cores. McDonald31 found no difference in the impact frac- ture resistance of mandibular incisors with or without posts. Eshelman and Sayegh32 reported similar results when posts were placed in extracted dog lateral incisors. Guzy and Nicholls33 determined that there was no sig- nificant reinforcement achieved by cementing a post into an endodontically treated tooth that was intact except for the access opening. Leary et al.34 measured the root deflection of endodontically treated teeth before and after posts of various lengths were cemented into prepared root canals. They found no significant differences in strength between the teeth with or with- out a post. Trope et al.35 determined that preparing a post space weakened endodontically treated teeth com- pared with ones in which only an access opening was made, but no post space. A potential situation where a post and core could strengthen a tooth was identified by Hunter et al.36 Figure 4 Traumatized tooth before endodontic procedure. Placement of using photoelastic stress analysis. They determined a bonded resin restoration in the access opening after root canal that removal of internal tooth structure during endo- treatment and whitening is the only treatment required since crowns dontic therapy is accompanied by a proportional do not enhance the longevity of anterior endodontically treated teeth. A increase in stress. They also determined that minimal crown will be indicated only when esthetic and functional needs cannot root canal enlargement for a post does not substan- be achieved through more conservative treatments. tially weaken a tooth but when excessive root Chapter 40 / Restoration of Endodontically Treated Teeth / 1435 canal enlargement has occurred, a post strengthens retention of a core that will provide appropriate sup- the tooth. Therefore, if the walls of a root canal are port for the definitive crown or prosthesis. Unfortu- thin due to the removal of internal root caries or nately, this primary purpose has not been completely overinstrumentation during post preparation, then a recognized. Hussey42 noted that 24% of general dental post may potentially strengthen the tooth. practitioners felt that a post strengthens teeth. A 1994 Two-dimensional finite element analysis was used survey (with responses from 1066 practitioners and in one study37 to determine the effect of posts on educators) revealed some interesting facts. Ten per- dentin stress in pulpless teeth. When loaded vertically cent of the dentist respondents felt that every endo- along the long axis, a post reduced maximal dentin dontically treated tooth should receive a post. It was stress by as much as 20%. However, only a small (3 to determined that 62% of dentists over age 50 believed a 8%) decrease in dentin stress was found when a tooth post reinforces the tooth whereas only 41% of the with a post was subjected to masticatory and trau- dentists under age 41 believed in that concept. matic loadings at 45 to the incisal edge. The authors Thirty-nine percent of part-time faculty, 41% of full- proposed that the reinforcement effect of posts is time faculty, and 56% of nonfaculty practitioners felt doubtful for anterior teeth because they are subjected that posts reinforce teeth.43 to angular forces. CONCLUSIONS CLINICAL DATA Both laboratory and clinical data fail to provide defi- Sorensen and Martinoff38 evaluated endodontically nitive support for the concept that posts strengthen treated teeth with and without posts and cores. Some endodontically treated teeth. Therefore, the purpose of the teeth were restored with single crowns while of a post is to provide retention for a core. others served as fixed partial denture abutments or removable partial denture abutments. Posts and cores significantly decreased the clinical success rate of teeth What Is the Clinical Failure Rate with single crowns, improved the clinical success of removable partial denture abutment teeth, and had of Posts and Cores? little influence on the clinical success of fixed partial Several studies provide clinical data regarding the 39 denture abutments. Eckerbom et al. examined the number of posts and cores that failed over certain time radiographs of 200 consecutive patients and reexa- periods44–55 (Table 1). When this number is divided by mined the patients radiographically 5 to 7 years later the total number of posts and cores placed, a failure to determine the prevalence of apical periodontitis. Of the 636 endodontically treated teeth evaluated, 378 had posts and 258 did not have posts. At both exam- inations, apical periodontitis was significantly more Table 1 Clinical Failure Rate of Posts and common in teeth with posts than in endodontically Cores 40 treated teeth without posts. Morfis evaluated the Percentage of incidence of vertical root fracture in 460 endodonti- Lead Author Study Length Clinical Failure cally treated teeth, 266 of which had posts. There were * 17 teeth with root fracture after a time period of at Turner (1982) 5 years 9 (6 of 66) least 3 years. Nine of the 17 fractured teeth had posts Sorenson (1984) 1–25 years 9 (36 of 420) * and 8 root fractures occurred in teeth without posts. Bergman (1989) 6 years 9 (9 of 96) * Morfis40 concluded that the endodontic technique can Weine (1991) 10 years or more 7 (9 of 138) * cause vertical root fracture. In an analysis of data from Hatzikyriakos (1992) 3 years 11 (17 of 154) * multiple clinical studies, Goodacre41 found that 3% of Mentink (1993) 1–10 years (mean 4.8) 8 (39 of 516) * teeth with posts fractured. None of these clinical data Wallerstedt (1984) 4–10 years (mean 7.8) 14 (8 of 56) provide definitive support for the concept that posts Torbjo¨rner (1995) 4–5 years 9 (72 of 788) and cores strengthen endodontically treated teeth or Balkenhol (2006) 1–9 years (mean 2.1) 7 (50 of 802) improve their long-term prognosis. Valderhaug (1997) 1–25 years (mean 2.1) 10 (40 of 397) Mean values§ 8 years 9 (292 of THE PURPOSE OF POSTS 3433) *Studies used to calculate mean study length. Since clinical and laboratory data indicate that teeth § are not strengthened by posts, their purpose is for Calculation made by averaging numerical data from all studies. 1436 / Endodontics percentage is determined. A 9% overall average for 99% after 10 years or more of follow-up to a 78% failure was calculated by averaging the failure percen- survival rate after a mean time of 5.2 years. The tages from 10 studies (an average study length of failure percentage per year has also been calculated 6 years). In these studies, the failure percentage ranged andrangedfrom1.56%peryear47 to 4.3% per from 7% to 14%. year.53 A review of more specific details from the 10 stu- dies provides insight into the length of each study and CONCLUSIONS the number of posts and cores evaluated. The findings Posts and cores had an average clinical failure rate of of a 5-year retrospective study of 66 posts and cores 9% (7 to 14% range) when the data from 10 studies 44 indicate there were 6 failures and a 9% failure rate. were combined (average study length of 8 years). Another study found that 17 of 154 posts failed after 3 years for an 11% failure rate.45 A failure rate of 9% was found in three studies.46–48 Two studies reported a 7% post and core failure rate after 9 years or What Are the Most Common Types more.49,55 An 8% failure rate (39 of 516 posts and of Post and Core Failures? cores) was published when 516 posts and cores placed by senior dental students were retrospectively evalu- Eight studies indicate that post loosening is the 50 most common cause of post and core fail- ated, whereas another study recorded a 14% failure 44,45,47,48,50,55–57 44 rate (8 failures in 56 posts and cores) from posts and ure (Figure 5). Turner reported on cores placed by dental students.51 A study of 397 posts 100 failures of post-retained crowns and indicated followed for 25 years reported a 10% post and core that post loosening was the most common type of failure rate after 25 years (40 of 397 posts failed).54 failure. Of the 100 failures, 59 were caused by post Kaplan-Meier survival statistics (percentage of loosening. The next most common occurrences were survival over certain time periods) were presented 42 apical abscesses followed by 19 carious lesions. 52 There were 10 root fractures and 6 post fractures. In or could be calculated from the data in nine studies 56 (Table 2). The survival rates ranged from a high of another paper by Turner, he reported the findings of a 5-year retrospective study of 52 post-retained crowns. Six posts had come loose, which was the most common failure. Lewis and Smith57 presented Table 2 Kaplain–Meier Survival Data (%) of Posts and Cores data regarding 67 post and core failures after 4 years. Forty-seven of the failures resulted from post loosen- Percentage ing, 8 from root fractures, 7 from caries, and 4 from Lead Author Study Length of Survival bent or fractured posts. Bergman et al.47 found 8 failures in 96 posts after 5 years. Six posts had loo- Robert (1970) 5.2 years mean 78 45 Wallerstedt (1984) 4–10 years range 86 sened and 2 roots had fractured. Hatzikyriakos et al. Sorenson (1985) 1–25 years range 90 reported on 154 posts and cores after 3 years. Five Weine (1991) 10 years or more 99 posts had come loose, five crowns had come loose, four roots fractured, and caries caused three failures. Hatzikyriakos (1992) 3 years 92 50 Mentink (1993) 1–10 years (mean 4.8) 82 Mentink identified 30 post loosenings and 9 tooth Creugers (1993) 6 years 81 (threaded fractures when evaluating 516 posts and cores over a 1- to 10-year time period (4.8 years mean study length). (meta-analysis) posts), 91 48 (cast posts) Torbjo¨rner et al. reported on the frequency of three Balkenhol (2006) 1–9 years range 89 technical failures (loss of retention, root fracture, and (mean 2.1) post fracture). They did not report biological failures. Valderhaug (1997) 1–25 years range 80 Loss of retention was the most frequent post failure, accounting for 45 of the 72 post and core failures. Root Chapter 40 / Restoration of Endodontically Treated Teeth / 1437

A B

Figure 5 Post and crown loosened from maxillary canine a few years after placement. A, Both the post/core and the crown came off. B, Clinical photo shows very little cervical tooth structure for retention of the crown.

fracture (Figure 6) was the second most common fail- Thirty-nine posts had loosened, eight had longitudinal ure cause followed by post fracture. Balkenhol et al.55 root fracture, and six had transverse root fracture. reported on 802 posts and cores over a 10-year period. In two studies, factors other than loss of retention were listed as the most common cause of failure.46,49 Sorensen and Martinoff46 evaluated 420 posts and cores and recorded 36 failures. Of the 36 failures, 8 were related to restorable tooth fractures, 12 to non- restorable tooth fractures, 13 to loss of retention, and 3 were caused by root perforations. Weine et al.49 found 9 failures in 138 cast posts and cores after 10 years or more. Three failures were caused by restorative proce- dures, two by endodontic treatment, two by period- ontal problems, and two by root fractures. No posts failed due to loss of retention. Four studies have provided data on the incidence of tooth fracture but no information regarding post loosen- ing. Linde58 reported that 3 of 42 teeth fractured, Ross59 found no fractures with 86 posts, Morfis40 found that 10 of 266 teeth fractured, and Wallerstedt51 identified 2 fractures with 56 posts. Loss of retention and tooth fracture (in that order of occurrence) are the 2 most common causes of Figure 6 Radiograph of a fractured maxillary first premolar with a post failure when these studies are collectively analyzed with excessive diameter and insufficient length, two problems frequently by averaging the numerical data from all the studies. seen in conjunction with fractured roots. Five percent of the posts placed (144 of 2,980 posts) 1438 / Endodontics

Table 3 Clinical Loss of Retention Associated with Posts and Cores Percentage of Percentage of Posts Failures Owing to Lead Author Study Length Placed that Loosened Post Form Loosening

Turner (1982) 5 years 9 (6 of 66) Appeared to be tapered * Turner (1982) 1–5 years or more * Tapered 59 (59 of 100) Sorensen (1984) 1–25 years 3 (13 of 420) Tapered and parallel 36 (13 of 36) Lewis (1988) 4 years * Threaded, tapered, and parallel 70 (47 of 67) Bergman (1989) 6 years 6 (6 of 96) Tapered 67 (6 of 9) Weine (1991) 10 years or more 0 (0 of 138) Tapered 0 (0 of 9) Hatzikyriakos (1992) 3 years 3 (5 of 154) Threaded, tapered, and parallel 29 (5 of 17) Mentink (1993) 1–10 years (mean 4.8) 6 (30 of 516) Tapered 77 (30 of 39) Torbjo¨rner (1995) 4–5 years 6 (45 of 788) Tapered and parallel 63 (45 of 72) Balkenhol (2006) 1–9 years (mean 2.1) 5 (39 of 802) Tapered 43 (39 of 90) Mean values§ 5 (144 of 2980) 56 (244 post loosenings of 439 total failures)

*Data not available in publication. §Calculation made by averaging numerical data from all studies.

Table 4 Clinical Tooth Fractures Associated with Posts and Cores Percentage of Teeth Restored with Post Form(s) Percentage of Failures Lead Author Study Length Posts that Fractured Studied Owing to Fracture

Turner (1982) 5 years 0 (0 of 66) Appeared to be tapered * Turner (1982) 1–5 years or more * Tapered, parallel, and threaded 10 (10 of 100) Sorensen (1984) 1–25 years 3 (12 of 420) Tapered and parallel 33 (12 of 36) Linde (1984) 2–10 years (5 years, 8 months mean) 7 (3 of 42) Threaded 38 (3 of 8) Lewis (1988) 4 years * Threaded, tapered, and parallel 12 (8 of 67) Bergman (1989) 6 years 3 (3 of 96) Tapered 33 (3 of 9) Ross (1980) 5 years or more 0 (0 of 86) Tapered, parallel, and threaded 0 (0 of 86) Morfis (1990) 3 years at least 4 (10 of 266) Threaded and parallel * Weine (1991) 10 years or more 1 (2 of 138) Tapered 50 (2 of 4) Hatzikyriakos (1992) 3 years 3 (4 of 154) Threaded, tapered, and parallel 3 (4 of 17) Mentink (1993) 1–10 years (mean 4.8) 2 (9 of 516) Tapered 23 (9 of 39) Wallerstedt (1984) 4–10 years (mean 7.8) 4 (2 of 56) Threaded 25 (2 of 8) Torbjo¨rner (1995) 4–5 years 3 (21 of 788) Tapered and parallel 29 (21 of 72) Balkenhol (2006) 1–9 years (mean 2.1) 2 (14 of 802) Tapered 15 (14 of 90) Valderhaug (1997) 1–25 years (mean 2.1) 1 (2 of 397) Tapered 5 (2 of 40) Mean values§ 2 (82 of 3827) 16 (90 tooth fractures of 576 total failures)

*Data not available in publication. §Calculation made by averaging numerical data from all studies. experienced loss of retention (Table 3). Two percent Which Post Design Produces the Greatest of the posts placed (82 of 3,827 posts) failed via toothfracture(Table4). Retention? LABORATORY DATA CONCLUSIONS There have been many laboratory studies comparing Loss of retention and tooth fracture are the two most the retention of various post designs. Threaded posts common causes of post and core failure. provide the greatest retention, followed by cemented, Chapter 40 / Restoration of Endodontically Treated Teeth / 1439 parallel-sided posts. Tapered cemented posts are the least retentive. Cemented, parallel-sided posts with serrations are more retentive than cemented, smooth- sided parallel posts. These laboratory data are dis- cussed below.

CLINICAL DATA There is clinical support for these laboratory studies. Torbjo¨rner et al.48 reported significantly greater loss of retention with tapered posts (7%) compared with par- allel posts (4%). Sorensen and Martinoff46 determined that 4% of tapered posts failed by loss of retention whereas 1% of parallel posts failed in that manner. Turner56 indicated that tapered posts loosened clini- cally more frequently than parallel-sided posts. Lewis Figure 7 Radiograph showing a threaded post that may have caused and Smith57 also found a higher loss of retention with root fracture in the second premolar. smooth-walled tapered posts than parallel posts. Berg- man et al.47 and Mentink et al.50 evaluated only tapered posts, and both studies reported that 6% of tapered posts failed via loss of retention, values higher than cated that tapered, threaded posts were the worst those recorded by Torbjo¨rner et al.48 and Sorensen 46 stress producers. When three types of threaded posts and Martinoff for parallel posts. 62 49 were compared in extracted teeth, Deutsch et al. Contrasting results were reported by Weine et al. found that tapered threaded posts increased root They found no clinical failures from loss of retention 45 fracture by 20 times that of the parallel threaded with cast tapered posts. Hatzikyriakos et al. studied posts (Figure 7). taperedthreadedposts,parallelcementedposts,and Laboratory testing of split threaded posts has pro- tapered cemented posts. The only posts that loosened vided varying results, but more research groups have from the root were parallel cemented posts. concluded that they do not reduce the stress asso- ciated with threaded posts. Thorsteinsson et al.63 CONCLUSIONS determined that split threaded posts did not reduce Tapered posts are the least retentive and threaded stress concentration during loading. In another study, posts the most retentive in laboratory studies. Most split threaded posts were found to produce installa- of the clinical data support the laboratory findings. tion stresses comparable to other threaded posts.64 Greater stress concentrations than those of some other threaded posts were reported under simulated functional loading.65–67 Rolf et al.68 found that a split threaded post produced comparable stress to one type Is There a Relationship Between Post of threaded post and less stress than a third threaded Form and the Potential for Root post design. Ross et al.59 determined that a split threaded post produced less root strain than two Fracture? other threaded posts and comparable strain to a third threaded post and a nonthreaded post. Another LABORATORY DATA research group69 concluded that the split threaded Using photoelastic stress analysis, Henry60 deter- design reduced the stresses caused during cementation mined that threaded posts produced undesirable compared with a rigid threaded post design. Multiple levels of stress. Another study used strain gauges photoelastic stress studies have concluded that posts attached to the root and compared four parallel- designed for cementation produced less stress than sided threaded posts with one parallel-sided non- threaded posts.60,61,68 threaded post.59 Two of the threaded posts produced When parallel-sided cemented posts were com- the highest strains, whereas two other threaded posts pared with tapered cemented posts, photoelastic stress caused strains comparable to the nonthreaded post. testing results generally favored parallel-sided posts. Standlee et al.,61 using photoelastic methods, indi- Using this methodology, Henry60 found that parallel- 1440 / Endodontics sided posts distribute stress more evenly to the root. Table 5 Post Form and Tooth Fracture Finite element analysis studies produced similar Clinical Data (Percentage of Post and Cores Studied that Failed 70,71 63,66 results. Two additional photoelastic studies via Tooth Fracture) concluded that parallel posts concentrate stress api- cally and tapered posts concentrate stress at the post– Threaded Posts Parallel-Sided Posts Tapered Posts core junction. Also using photoelastic testing, Assif (Lead Author) (Lead Author) (Lead Author) 72 et al. found that tapered posts showed equal stress 40 (2 of 5) (Sorensen) 0 (0 of 170) 7 (18 of 245) (Sorensen) distribution between the cementoenamel junction and (Sorensen) the apex compared with parallel posts that concen- 0 (0 of 10) (Ross) 2 (5 of 332) 4 (16 of 456) (Torbjo¨rner) trated the stress apically. (Torbjo¨rner) When fracture patterns in extracted teeth were used 4 (2 of 56) (Wallerstedt) 0 (0 of 39) (Ross) 1 (2 of 138) (Weine) 7 (3 of 42) (Linde) 3 (4 of 146) (Morfis) 2 (9 of 516) (Mentink) to compare parallel and tapered posts, the evidence 7 (4 of 56) (Morfis) 3 (3 of 96) (Bergman) favoring parallel posts was less favorable. Sorensen and 0 (0 of 38) (Ross) Engelman73 determined that tapered posts caused more 3 (2 of 64) (Morfis) extensive fractures than parallel-sided posts did, but the 2 (14 of 802) (Balkenhol) load required to create fracture was significantly higher 1 (2 of 397) (Valderhaug) 7% Mean* (11 of 169) 1% Mean* (9 of 687) 2% Mean* (66 of 2752) with tapered posts. Lu,28 also using extracted teeth, found no difference in the fracture location between *Calculation made by averaging numerical data from all studies. prefabricated parallel posts and cast posts and cores. Assif et al.74 tested the resistance of extracted teeth to fracture when the teeth were restored with either parallel Combining the five studies that reported data relative or tapered posts and complete crowns. No significant to threaded posts produced a mean fracture rate of 7% differences were noted, and post design did not influ- (11 fractures from 169 posts). The four clinical studies ence fracture resistance. that contain fracture data from parallel-sided cemented In analyzing the stress distribution of posts, it was posts produced a mean fracture incidence of 1% noted that tapered posts generate the least cementation (9 fractures from 687 posts). From the seven studies stressandshouldbeconsideredforteeththathavethin reporting root fracture with tapered posts, there is a root walls, are nearly perforated, or have perforation mean fracture rate of 2% (66 root fractures from repairs.66 2,752 posts). This combined study data support the previously cited photoelastic laboratory stress tests, indicating that the greatest incidence of root frac- CLINICAL DATA turesoccurredwiththreadedpostsandthatthelow- There are several clinical studies that provide data est incidence of root fracture was associated with related to the incidence of root fracture associated parallel cemented posts. In a meta-analysis of with different post forms. Some of these studies pro- selected clinical studies, Creugers et al.52 calculated vide a comparison of multiple post forms, whereas a 91% tooth survival rate for cemented cast posts and other studies evaluated only one type of post. Com- cores and an 81% survival rate for threaded posts bining all the root fracture data for each post form with resin cores. from both types of studies reveals some interesting While the combined data from all the studies for each trends (Table 5). Five studies present data regarding type of post revealed certain trends, analysis of indivi- root fractures and threaded posts,40,46,51,58,75 four dual studies (where multiple post forms were compared regarding fractures associated with parallel-sided in the same study) produced less conclusive results. One cemented posts40,46,48,75 and nine related to tapered study of threaded posts and cemented posts determined cemented posts.40,46–49,50,54,55,75 If the total number of that teeth with threaded posts were lost more frequently threaded posts evaluated in the five studies is divided than teeth with cast posts.39 In three other clinical into the total number of fractures found with comparisons of threaded and cemented posts, no tooth threaded posts, a percent value can be determined fracture differences were noted.40,45,75 In addition to the that represents the average incidence of tooth fracture comparisons of threaded and cemented posts, four clin- associated with threaded posts in the five studies. The ical studies provide data comparing the tooth fracture same data can be calculated for parallel cemented and incidences associated with parallel-sided and tapered tapered cemented posts, permitting a comparison of posts. In comparing parallel and tapered posts by the root fracture incidences associated with these reviewing dental charting records, a higher failure rate three post forms. was reported with tapered posts than with parallel posts Chapter 40 / Restoration of Endodontically Treated Teeth / 1441 in two studies, and the failures were judged to be more highest root fracture incidence (7%) compared with severe with tapered posts.46,48 Two other clinical studies tapered cemented posts (2%) and parallel cemented determined that there were no differences between tapered posts (1%). Analysis of individual clinical studies as and parallel-sided posts.48,75 Hatzikyriakos et al.45 found opposed to the combined data produces less conclu- no significant differences between 47 parallel cemented sive results. Additional comparative clinical studies posts and 44 tapered cemented posts after three years of would be beneficial, including designs that have not service. Ross75 evaluated 86 teeth with posts and cores that yet been evaluated in comparative studies. had been restored at least five years previously. No fracture differences were found between 38 tapered cemented posts and 39 parallel cemented posts. What Is the Proper Length for a Post? Unfortunately, the total number of clinical studies that compared multiple post forms in the same study A wide range of recommendations have been made is limited. Also, several factors may have affected the regarding post length, which includes the following: findings of available studies. Two of the papers that 1. The post length should equal the incisocervical or contained a comparison of multiple post forms cov- occlusocervical dimension of the crown.76–83 ered sufficiently long time periods (10 to 25 years) 2. The post should be longer than the crown.84 that the tapered cemented posts may have been in 3. The post should be one-third of the crown place for much longer time periods than the paral- length.85 lel-sided cemented posts (due to the later introduc- 86,87 46,48 4. The post should be half of the root length. tion of parallel posts into the dental market). The 5. The post should be two-thirds of the root mean time since the placement of each post form was length.88–92 not identified in these studies. Also, both of these 6. The post should be four-fifths of the root studies were based on reviews of patient records length.93 (rather than clinical examinations) and depended on 7. The post should be terminated halfway between the accuracy of dental charts in determining if and the crestal bone and the root apex.94–96 when posts failed as well as the cause of the failure. 8. The post should be as long as possible without Another factor that affected the results of many of the disturbing the apical seal.60 referenced clinical studies was the length of the posts. For instance, in Sorensen and Martinoff’s study,46 A review of scientific data provides the basis for dif- 44% of the tapered cemented posts had a length that ferentiating between these varied guidelines. was half (or less than half) the incisocervical/occluso- While short posts have never been advocated, cervical dimension of the crown whereas only 4% of they have been frequently observed during radio- the parallel cemented posts were that short. Since graphic examinations (Figures 8 and 9). Grieve and short posts have been associated with higher root stresses in laboratory studies, the difference in post length may have affected their findings where tooth fractures occurred with 18 of 245 tapered posts com- pared with no fractures with 170 parallel posts.

CONCLUSIONS When evaluating the relationship between post form and root fracture, laboratory tests generally indicate that all types of threaded posts produce the greatest potential for root fracture. When comparing tapered and parallel cemented posts by using photoelastic stress analysis, the results generally favor the parallel cemented posts. However, the evidence is mixed when the comparison between tapered and parallel posts is based on fracture patterns in extracted teeth created by applying a force via a mechanical testing machine. When evaluating the combined data from multiple Figure 8 Radiograph displaying a very short post in the distal root of a clinical studies, threaded posts generally produced the first molar. The prosthesis has loosened. 1442 / Endodontics

Johnson and Sakumura99 determined that posts that were three-fourths or more of the root length were up to 30% more retentive than posts that were half of the root length or equal to the crown length. Leary et al.100 indicated that posts with a length at least three-fourths of the root offered the greatest rigidity and least root bending. These data indicate that post length would appropri- ately be three-fourths that of the root length. However, some interesting results occur when post length guide- lines of two-thirds to three-fourths of the root length are applied to teeth with average, long, and short root lengths. It was determined that a post approaching this recommended length range is not possible without compromising the apical seal by retaining less than 5mmofgutta-percha.101 When post length was half that of the root, the apical seal was rarely compromised on average length roots. However, when posts were two-thirds of the root length, many of the average and short roots would have less than the optimal gutta- percha seal. Shillingburg et al.102 also indicated that making the post length equal to the clinical crown Figure 9 Radiograph of a second premolar with a very short post; the lengthcancausetheposttoencroachonthe4-mm lack of adequate retention for the core can result in the prosthesis ‘‘safety zone’’ required for an apical seal. loosening. Abou-Rass et al.103 proposed a post length guide- line for maxillary and mandibular molars based on 97 the incidence of lateral root perforations when post McAndrew found that only 34% of 327 posts preparations were made in 150 extracted teeth. They were as long as the incisocervical length of the determined molar posts should not be extended more crown. In a clinical study of 200 endodontically 75 than 7 mm apical to the root canal orifice. treated teeth, Ross determined that only 14% of When teeth have diminished bone support, stresses posts were two-thirds or more of the root length increase dramatically and are concentrated in the and 49% of the posts were one-third or less of the dentin near the post apex.104 A recent finite element root length. A radiographic study of 217 posts model study established a relationship between post determined that only 5% of the posts were two- length and alveolar bone level.105 To minimize stress thirds to three-fourths of the root length.98 In a 44 in the dentin and in the post, the post should extend retrospective clinical study of 52 posts, Turner more than 4 mm apical to the bone. radiographically compared the length of the post with the maximal length available if 3 mm of CONCLUSIONS gutta-percha was retained. Posts that came loose used only 59% of the ideal length and only 37% of Reasonable clinical guidelines for length include the the posts were longer than the proposed maximal following: length. Nine millimeters wasproposedastheideal 1. Make the post approximately three-fourths of the length. Short posts have been associated with length of the root when treating long-rooted higher root stresses36,64,66,70,71 and a greater ten- teeth. dency for root fracture to occur. 2. When average root length is encountered, post Sorensen and Martinoff46 determined that the clin- length is dictated by retaining 5 mm of apical ical success was markedly improved when the post was gutta-percha and extending the post to the equal to or greater than that of the crown length. gutta-percha (Figure 10). Chapter 40 / Restoration of Endodontically Treated Teeth / 1443

3. Whenever possible, posts should extend at least 4 mm How Much Gutta-Percha Should apical to the bone crest to decrease dentin stress. 4. Molar posts should not be extended more than Be Retained to Preserve the 7 mm into the root canal apical to the base of the Apical Seal? pulp chamber (Figure 11). It has been determined that when 4 mm of gutta- percha was retained, only 1 of 89 specimens showed leakage, whereas 32 of 88 specimens leaked when only 2 mm of gutta-percha was retained.106 Two studies found no leakage at 4 mm,107,108 and two additional studies found little leakage at 4 mm.106,109 Portell et al.110 foundthatmostspeci- mens with only 3 mm of apical gutta-percha had some leakage. When the leakage associated with 3, 5, and 7 mm of gutta-percha was compared, Mat- tison et al.111 found significant leakage differences between each of the dimensions. They proposed that at least 5 mm of gutta-percha is required for an adequate apical seal. Nixon et al.112 compared the sealing capabilities of 3, 4, 5, 6, and 7 mm of apical gutta-percha using dye penetration. The greatest leakage occurred when only 3 mm was retained, and it was significantly different from the other groups. They also noted a significant decrease in leakage when 6 mm of gutta-percha remained. Raiden and Gendelman113 cemented Figure 10 Five millimeters of gutta-percha was retained in the maxillary stainless steel posts with zinc phosphate cement in premolar and the post extended to that point. teeth with residual root canal fillings of 1, 2, 3, and 4 mm. They tested apical leakage using a passive dye system. They concluded that 4 mm of apical seal provided a leakage value of zero. Kvist et al.114 examined radiographs from 852 clinical endodontic treatments. Posts were present in 424 of the teeth. Roots with posts in which the remaining root fill- ing material was shorter than 3 mm showed a significantly higher frequency of periapical radiolucen- cies. Using a pressure-driven tracer assay, Wu et al.115 and Abramovitz et al.116 found that 4 or 5 mm of apical seal was inferior in their ability to prevent leakage, compared with an original full-length root canal filling. Similarly, Metzger et al.117 compared the sealing capabilities of 3, 5, 7, and 9 mm of apical gutta-percha using a pressure-driven radio- active tracer assay. They concluded that the sealing is proportional to the length of the remaining fill- ing and that original full-length root canal fillings Figure 11 The post in the distal canal of the mandibular molar extends have a superior seal compared with 3, 5, and 7 mm to a maximal length of 7 mm. of apical gutta-percha. 1444 / Endodontics

CONCLUSIONS Does Post Diameter Affect Retention and Since there is greater leakage when only 2 to 3 mm of the Potential for Tooth Fracture? gutta-percha is present (Figure 12), 4 to 5 mm should be retained apically to ensure an adequate seal. Studies relating post diameter to post retention have Although studies indicate that 4 mm produces an failed to establish a definitive relationship. Two stu- adequate seal, stopping precisely at 4 mm is difficult dies determined that there was an increase in post and radiographic angulation errors could lead to retention as the diameter increased,102,118 whereas retention of less than 4 mm. Therefore, 5 mm of three studies found no significant retention changes gutta-percha should be retained apically. This seal is with diameter variations.119,110,120 Krupp et al.121 complemented by the seal provided by the post and indicated that post length was the most important core, and the overlying crown (Figure 11). factor affecting retention and post diameter was a secondary factor. A more definitive relationship has been established between post diameter and stress in the tooth. Mat- tison122 found that as the post diameter increased, stress increased in the tooth. Trabert et al.123 mea- sured the impact resistance of extracted maxillary central incisors as post diameter increased and found that increasing the post diameter decreased the tooth’s resistance to fracture. Deutsch et al.62 deter- mined that there was a six-fold increase in the poten- tial for root fracture with every millimeter decrease in tooth diameter. However, two finite element stu- dies failed to find higher tooth stresses with larger- diameter posts.70,71

CONCLUSIONS Laboratory studies relating retention to post dia- meter have produced mixed results, whereas a more Figure 12 Less than 2 mm of gutta-percha remains in the maxillary first definitive relationship has been established between premolar apical to the cast post and core, increasing the risk of failure. root fracture and large-diameter posts (Figure 13).

A B

Figure 13 Excessive post diameters. A, Large-diameter post placed in the palatal root of the maxillary molar. B, Large-diameter threaded post caused fracture of the maxillary second premolar. The radiographic appearance of the bone is typical of a fractured root—a teardrop-shaped lesion with diffuse border. Chapter 40 / Restoration of Endodontically Treated Teeth / 1445

What Is the Relationship Between Table 6 Post Space Preparation Widths (in Millimeters) Post Diameter and the Potential for Root Maxillary Mandibular Tilk Shillingburg Tilk Shillingburg Perforations? et al et al et al et al In a literature review of guidelines associated with post 124 Central incisor 1.1 1.7 0.7 0.7 diameter, Lloyd and Palik indicated that there are Lateral incisor 0.9 1.3 0.7 0.7 three distinct philosophies of post space preparation. Canine 1.0 1.5 0.9 1.3 One group advocates the narrowest diameter for fabri- First premolar cation of a certain post length (the conservationists). (B) 0.9 0.9 (L) 0.9 0.9 Another group proposes a space with a diameter that Second premolar 0.9 1.1 0.9 1.3 does not exceed one-third of the root diameter (the First molar proportionists). The third group advises leaving at least (MB) 0.9 1.1 (MB) 0.9 1.1 1 mm of sound dentin surrounding the entire post (the (DB) 0.8 1.1 (ML) 0.8 0.9 preservationists). (L) 1.0 1.3 (D) 0.9 1.1 Based on the proportional concept of one-third of the Second molar (MB) - 1.1 (MB) - 0.9 root diameter, three articles measured the root diameters (DB) - 0.9 (ML) - 0.9 of extracted teeth and proposed post diameters that (L) - 1.3 (D) - 1.1 would not exceed this proportion.102,103,125 Tilk et al.125 examined 1,500 roots. They measured the narrowest mesiodistal dimension at the apical, middle, and cer- vical one-thirds of the teeth except the palatal root of roots (mandibular distal and maxillary palatal), they the maxillary first molar that was measured faciolin- determined that posts should not be extended more gually. Based on the 95% confidence level that post than 7 mm into the root canal (apical to the pulp width would not exceed one-third of the apical width chamber) due to the risk of perforation. Regarding of the root, they proposed the following post widths instrument size, they concluded that post prepara- (Table 6): small teeth such as mandibular incisors (0.6 tions can be safely completed by using a No. 2 Peeso to 0.7 mm); large-diameter roots such as maxillary instrument, but perforations are more likely when the central incisors and the palatal root of the maxillary larger Nos. 3 and 4 Peeso instruments are used. first molar (1.0 mm); and for the remaining teeth (0.8 Raiden et al.126 evaluated several instrument dia- to 0.9 mm). 102 meters (0.7, 0.9, 1.1, 1.3, 1.5, and 1.7 mm) to deter- Shillingburg et al. measured 700 root dimensions mine which one(s) would preserve at least 1 mm of to determine the post diameters that would minimize root wall thickness following post preparation in max- the risk of perforation. Also based on not exceeding illary first premolars. They determined that instru- one-third of the mesiodistal root width, they recom- ment diameter must be small (0.7 mm or less) for mended the following post diameters (see Table 6): maxillary first premolars with single canals because mandibular incisors (0.7 mm); maxillary central inci- the mesial and distal developmental root depressions sors or other large roots (1.7 mm—which was the restrict the amount of available tooth structure in the maximal recommended dimension); post tip diameter centrally located single root canal. However, when (at least 1.5 mm less than the root diameter at that there are dual canals, the instrument can be as large point); and post diameter at the middle of the root as 1.1 mm because the canals are located buccally and length (2.0 mm less than the root diameter). lingually into thicker areas of the roots. Post spaces were prepared in 150 extracted maxil- lary and mandibular molars by using different instru- ment diameters and the resulting incidences of CONCLUSIONS perforations were recorded.103 The authors deter- Instruments used to prepare posts should be related mined that the mesial roots of mandibular molars in size to root dimensions to avoid excessive post and the buccal roots of maxillary molars should not diameters that lead to root perforation (Figure 14). be used for posts due to the higher risk of perforation Safe instrument diameters to use are 0.6 to 0.7 mm on the furcation side of the root. For the principal for small teeth such as mandibular incisors and 1 to 1446 / Endodontics

removal of gutta-percha and no removal of gutta-percha. By contrast, Dickey et al.129 found significantly greater leakage with immediate gutta-percha removal. Kwan and Harrington130 tested the effect of immedi- ate gutta-percha removal using both warm instruments and rotary instruments. There was no significant dif- ference between the controls and immediate removal using warm pluggers and files. Compared with the controls, there was significantly less leakage with immediate removal of gutta-percha when using Gates Glidden drills. Karapanou et al.131 compared immediate and delayed removal of two sealers (a zinc oxide–eugenol-based sealer and a resin-based sealer). No difference between immediate and delayed removal was noted with the resin-based sealer, but delayed removal of the zinc oxi- Figure 14 Excessive post diameter in the maxillary second premolar de–eugenol-based sealer produced significantly greater created a perforation in the mesial root concavity. Note the distinct leakage. Abramovitz et al.116 compared immediate border and round form of the radiolucent lesion, characteristics indica- gutta-percha removal using hot pluggers and delayed tive of a root perforation. gutta-percha removal (after 2 weeks) using Gates Glid- den drills. They found no difference between the two methods. 1.2 mm for large-diameter roots such as the max- Portell et al.132 found that delayed gutta-percha illary central incisors. Molar posts longer than 7 mm removal (after 2 weeks) caused significantly more leakage have an increased chance of perforations and there- than immediate removal when only 3 mm of gutta- fore should be avoided even when using instruments percha was retained apically. Fan et al.133 found more of an appropriate diameter. leakage from delayed removal of gutta-percha. Solano et al.134 found a less significant difference in apical leakage between teeth whose post spaces were prepared at the time of the obturation and 1 week later using warm gutta- Can Gutta-Percha Be Removed percha condensation and AH Plus sealer. Immediately after Endodontic Treatment CONCLUSIONS and a Post Space Prepared? Adequately condensed gutta-percha can be safely removed immediately after endodontic treatment. Several studies indicate that there is no difference in the leakage of the root canal filling material when the post space is prepared immediately after completing endo- dontic therapy.107,109,127,128 Bourgeois and Lemon127 What Instruments Remove Gutta-Percha found no difference between immediate preparation of a post space and preparation 1 week later when 4 mm of Without Disturbing the Apical Seal? gutta-percha were retained. Zmener109 found no differ- Three methods have been advocated for the removal ence in dye penetration between gutta-percha removal of gutta-percha during preparation of a post space: after 5 minutes and 48 hours. Two sealers were tested chemical (oil of eucalyptus, oil of turpentine, and and 4 mm of gutta-percha was retained apically. chloroform), thermal (electrical or heated instru- When lateral condensation of gutta-percha was used, ments), and mechanical (Gates Glidden drills, Peeso Madison and Zakariasen107 found no difference in the reamers, etc.). The chemical removal of gutta-percha dye penetration between immediate removal and 48- for post space preparation is not utilized for hour removal. Using the chloropercha filling technique, specific reasons (microleakage, inability to control Schnell128 found no difference between immediate removal).111,127 However, thermal and mechanical Chapter 40 / Restoration of Endodontically Treated Teeth / 1447 techniques or a combination of both are routinely Bypassing fractured instruments seems to be the best used. approach. Hu¨lsmann and Schinkel140 reported an Multiple studies have determined that there is no overall success rate of 68% when bypassing broken difference in leakage between removing gutta-percha instruments from canals in vivo. Ward et al.141 with hot instruments and removing it with rotary reported an overall success rate of 73%. Suter et al.142 instruments.106,111,135 Suchina and Ludington135 and with the use of an dental operating microscope were Mattison et al.111 found no difference between hot able to achieve an overall success rate of 87% when instrument removal and removal with Gates Glidden removing broken instruments. drills. Camp and Todd106 found no difference between Peeso reamers, Gates Glidden drills, and hot instru- CONCLUSIONS 136 ments. Hiltner et al. compared warm plugger If a separated fragment of any instrument cannot be removal with two types of rotary instruments (GPX removed from the canal during post space prepara- burs and Peeso reamers). There were no significant tion, it should be bypassed or left in the canal. differences in dye leakage between any of the groups. Contrasting results were found by Haddix et al.137 They measured significantly less leakage when gutta-percha was removed with a heated plugger than when either a Can a Portion of a Silver Point GPX instrument or Gates Glidden drills were used. Be Removed and Still Maintain the DeCleen138 found that it is desirable to remove gutta- percha using a heated instrument first, and then using a Apical Seal? small Gates Glidden drill. Using a pressure-driven In one study, all the specimens leaked when 1 mm of a radioactive tracer assay, Abramovitz et al.116 found no 5-mm long silver point was removed by using a round difference in apical leakage between hot pluggers and bur.109 Neagley108 found that removal of the filling Gates Glidden drills. Balto et al.139 compared two meth- material coronal to the silver point with a Peeso reamer ods of gutta-percha removal and their impact on apical caused no leakage. However, when all the filling mate- leakage. They found that removing gutta-percha with rials and 1 mm of the silver point were removed, Peeso reamers showed less leakage compared with using complete dye penetration occurred in eight of nine ahotplugger. specimens. CONCLUSIONS CONCLUSIONS Both rotary instruments and hot hand instruments The removal of a portion of a silver point during post can be safely used to remove adequately condensed preparation causes apical leakage. gutta-percha when 5 mm is retained apically.

How Soon should the Definitive Can a Separated Instrument Be Removed Restoration Be Placed After Post During Post Space Preparation and Still Space Preparation? Maintain the Apical Seal? ONE-PIECE PROVISIONAL RESTORATION Following root canal therapy, the endodontically trea- It is well established that a deficient root canal obtura- ted tooth could present with a separated instrument tion and a poor coronal restoration will potentially (files, rotary instruments, etc.) in any part of the allow endotoxins, bacteria, and saliva to penetrate the canal. Attempts to remove these fragments prior to root canal causing periapical inflammation.143–149 post space preparation could lead to loss of apical seal, Provisional restorations are mainly used to provide perforations, ledge formation, and/or over enlarge- the patient with a functional and esthetic restoration. ment of the canal. A decision to bypass or remove They also protect the hard and soft tissues prior to the fragment will depend on the type and position of placement of the definitive restoration. However, pro- the broken instrument and should be determined by visional restorations are considered restorations with an endodontist with the use of an operating micro- poor coronal seal. Several studies indicate that there is scope. significant coronal leakage when the tooth is restored 1448 / Endodontics with a provisional restoration.139,150–153 Demarchi restoration leads to a high success rate of endodon- et al.150 found that a tooth restored with a temporary tically treated teeth. Contrasting results were post–crown combination had significantly greater reported by Tronstad et al.156 who found that the leakage than definitively cemented prefabricated posts quality of the endodontic treatment was significantly and separate crowns. Similar results were found by Fox more important than that of the coronal restoration. et al.151 when they compared cast posts and cores cemented with zinc phosphate cement, prefabricated CONCLUSIONS posts and composite resin cores cemented with resin cement, and provisional post–crowns cemented with Following endodontic treatment, post space prepara- zinc oxide–eugenol cement. In a 3-year retrospective tion should be performed and a post definitively clinical study, Lynch et al.152 evaluated 176 endodonti- cemented as soon as possible: the same day for a cally treated teeth. They found that the loss of endo- prefabricated post, and as soon as possible for a cus- dontically treated teeth occurred more often with those tom-fabricated post and core. The prepared tooth teeth restored with provisional restorations. Following should then be restored with a well-fitting provisional these results, several studies139,151 suggested that the restoration (good marginal seal and occlusion) fol- definitive post and restoration should be cemented as lowed by cementation of the definitive crown in as soon as possible to prevent recontamination of the root short a time as possible. canal. However, to minimize leakage and enhance long-term success, the definitive coronal restoration should be of superior quality.147,154–157 Does the Use of a Cervical Ferrule that Engages Tooth Structure Help TEMPORARY CORONAL ACCESS FILLING Prevent Tooth Fracture? Balto et al.139 compared the leakage of different Survey data have been published that indicate the provisional materials used in post-prepared root percentage of respondents who felt a ferrule (circum- canals. They found that none of the provisional ferential band of metal) increased a tooth’s resistance restorations tested (Cavit, IRM, and Temp Bond) to fracture.43 Fifty-six percent of general dentists, 67% prevented coronal leakage when left for a long period of prosthodontists, and 73% of board-certified of time (30 days). Safavi et al.153 evaluated the prog- prosthodontists felt that core ferrules increased a nosis of endodontically treated teeth following tooth’s fracture resistance. To investigate this concept, delayed placement of the definitive coronal restora- several research studies have been performed. Some of tion. A total of 464 endodontically treated teeth were the articles found ferrules are beneficial whereas followed radiographically. They found a higher suc- others found no increase in fracture resistance. cess rate when the definitive restorations (silver The results appear indecisive until differences amalgam, composite resin, or definitive restoration between study designs are analyzed. First, some of with or without posts and cores) were placed as the studies tested ferrules that were part of a cast compared with teeth restored with provisional cor- metal core (core ferrules),158–162 whereas other studies onal access restorations (IRM or Cavit). evaluated the effectiveness of ferrules created by the Torabinejad et al.147 found that defective restora- overlying crown engaging tooth structure.163–176 One tions could cause root canal system reinfection study evaluated both core ferrules and crown fer- within 19 days. Ray and Trope154 found that a com- rules.177 Second, there were differences in the form bination of a poor coronal restoration and poor of the ferrule, and therefore, the manner by which the endodontic treatment resulted in a high failure rate metal engaged tooth structure (beveled sloping sur- of endodontically treated teeth. In a retrospective face versus extension over relatively parallel prepared study, Iqbal et al.155 found that a combination of tooth structure). Third, there were variations in the good quality endodontic treatment and coronal amount of tooth structure encompassed by the Chapter 40 / Restoration of Endodontically Treated Teeth / 1449

Table 7 Comparison of Studies and Effectiveness of Various Core and Crown Ferrules Study Ferrule Form Was Ferrule Effective? Materials/Type of Test

Barkhordar (1989) 2 mm parallel extension Yes Extracted teeth/angular lingual force of core over the tooth applied to p and c (no overlying crown) Sorensen (1990) 1 mm wide 60 bevel at No Extracted teeth/angular lingual force applied to the tooth-core junction p and c (with overlying crown) Tjan (1985) 60 bevel at the tooth-core No Extracted teeth/angular lingual force applied to junction p and c (no overlying crown) Loney (1990) 1.5 mm parallel extension No Photoelastic teeth/angular lingual force applied to of core over the tooth p and c (no overlying crown) Hemmings (1991) 45 bevel Yes Extracted teeth/torsional force applied to p and c (no overlying crown) Saupe (1996) 2 mm parallel extension No Extracted teeth/angular lingual force applied to of core over thin dentin p and c (no overlying crown) wall (0.5–0.75 mm thick) Sorensen (1990) 130 sloping finish line No Extracted teeth/p and c with crown 1–2 mm of tooth grasped by Yes Extracted teeth/p and c with crown crown Libman (1995) 0.5–1 mm of prepared tooth No Extracted teeth/p and c with crown/cyclic loading grasped by crown 1.5–2 mm of prepared tooth Yes Extracted teeth/p and c with crown/cyclic loading grasped by crown Milot (1992) 1 mm wide 60 bevel Yes Plastic analogues of teeth/p and c with crowns grasped by crown Isidor (1999) 1.25 mm of prepared tooth Yes Bovine teeth/cyclic angular load/p and c grasped by crown with crown 2.5 mm of prepared tooth Yes, but more effective than 1.25 mm Bovine teeth/cyclic angular load/p and c with grasped by crown crown Hoag (1982) 1–2 mm of prepared tooth Yes Extracted teeth/p and c with crown grasped by crown Gegauff (2000) 2 mm of prepared tooth Yes Composite teeth/p and c with crown grasped by crown; 0 mm of prepared tooth grasped by a crown ferrules. Table 7 permits a comparison of the studies fracture. Assif et al.179 found no difference in the tooth and the effectiveness of the various core and crown fracture patterns of parallel posts, tapered posts, and ferrules. parallel posts with a tapered end when they were The data generally indicate that ferrules formed as covered by a crown that grasped 2 mm of tooth part of the core are less effective than ferrules created structure. Akkayan et al.170 found no significant dif- when the overlying crown engages tooth structure. In ference between fiber-reinforced and zirconia dowels four of the six core ferrule studies, they were found to when the ferrule length was 2 mm. be ineffective.159,160,162,177 Also, in one of the two The data also support the concept that ferrules that studies where the core ferrule was effective, the ferrule grasp larger amounts of tooth structure are more form was a 2-mm parallel extension of the core over effective than those engaging only a small amount of tooth structure as opposed to a bevel.158 In the other tooth structure. In both the core and crown ferrule study where core ferrules were found to be effective, a studies, the tooth’s resistance to fracture was increased torsional force was used as opposed to an angular when a substantive amount of tooth structure was lingual force.161 In the crown ferrule studies, most of engaged (2 mm in the core ferrule studies and 1 to the ferrules effectively increased a tooth’s resistance to 2 mm in the crown ferrule studies). Libman and fracture. Only when the crown ferrule was of minimal Nicholls163 found the 0.5- to 1.0-mm crown ferrule dimension or had a sloping form, it was found to be to be ineffective whereas a 1.5- to 2.0-mm crown ineffective.163,177 In support of these studies, Rosen ferrule to be effective. Isidor et al.165 determined that and Partida-Rivera178 found that a 2-mm cast gold increasing the crown ferrule length significantly collar (not part of the post and core) was very effective increased the number of cyclic cycles required to cause in preventing root fracture when a tapered screw post specimen failure. They compared no ferrule with 1.25 was intentionally threaded into roots so as to induce and 2.55 mm crown ferrules. They concluded that 1450 / Endodontics ferrule length was more important than post length in increasing a tooth’s resistance to fracture under cyclic loading. Zhi-Yue and Yu-Xing169 found that a 2-mm crown ferrule effectively enhanced the fracture strength of endodontically treated teeth when a cast post and core was used. Pereira et al.176 compared the effect of no crown ferrule with 1, 2, and 3-mm crown ferrules. They found that a 3-mm crown fer- rule significantly increased the fracture resistance of endodontically treated teeth compared with a 2-mm crown ferrule. The form of the prepared ferrule also appears to affect a tooth’s fracture resistance in the previously cited studies. Only one beveled/sloping ferrule was effective in enhancing a tooth’s fracture resistance Figure 15 Types of ferrules. A, Tooth prepared for a post and core. and that was when a torsional force was applied to B, Post and core has been cemented into the tooth. The arrows note the tooth. Tan et al.172 compared a 2-mm uniform how the core has created a ferrule around the tooth (note the reduction crown ferrule that extended around the entire crown in the width of remaining coronal tooth structure to develop this core circumference with a 2-mm nonuniform crown ferrule). C, A metal ceramic crown has been cemented over the core. ferrule where the ferrule was only 0.5 mm on the The arrows show how the crown encompasses the tooth cervically, proximal surfaces. The uniform ferrule produced sig- establishing a crown ferrule. nificantly greater fracture resistance than a nonuni- form ferrule. In an in vitro study, Naumann et al.173 to fracture. Ferrules are more effective when the crown evaluated the effect of chewing simulation on the encompasses relatively parallel prepared tooth structure fracture resistance of maxillary endodontically treated than when it engages beveled/sloping tooth surfaces. teeth with incomplete crown ferrules. The greatest Ferrules that encompass 2 mm of tooth structure variation of failure load was associated with the around the entire circumference of a tooth are more absence of portions (facial, palatal, or interproximal) effective than nonuniform ferrules. of the crown ferrule. Ng et al.174 investigated the effect of limited residual axial tooth structure on the frac- ture resistance of maxillary anterior endodontically Post and Core Placement Techniques treated teeth. They found that in the absence of 360 of circumferential coronal tooth structure, the loca- PRETREATMENT DATA REVIEW tion of the remaining coronal tooth structure may be When it has been determined that a post and core is an important factor for determining the fracture resis- required to properly retain a definitive single crown tance of endodontically treated teeth. The palatal axial or fixed partial denture, the following characteristics wall was as effective as a 360 circumference in pro- should be determined prior to beginning the clinical viding fracture resistance. procedures associated with the fabrication of a post and core. CONCLUSIONS Differences of opinion exist regarding the effectiveness POST LENGTH of ferrules in preventing tooth fracture. Ferrules have Since 5 mm of gutta-percha should be retained api- been tested when they are part of the core and also cally to ensure a favorable seal (as measured radio- when the ferrule is created by the overlying crown graphically), posts should be extended to that length engaging tooth structure. Most of the data indicate that in all teeth except molars. With molars, posts should a ferrule created by the crown encompassing tooth be placed in the primary roots (palatal root of max- structure is more effective than a ferrule that is part illary molars and distal roots of mandibular molars) of the post and core (Figure 15). Ferrule effectiveness is and should not be extended more than 7 mm apical to enhanced by grasping larger amounts of tooth struc- the origin of the root canal in the base of the pulp ture. The amount of tooth structure engaged by the chamber (Figure 11). Extension beyond this length overlying crown appears to be more important than can lead to root perforation or only very thin areas the length of the post in increasing a tooth’s resistance of remaining tooth structure. Chapter 40 / Restoration of Endodontically Treated Teeth / 1451

POST DIAMETER DENTIN THICKNESS AFTER ENDODONTIC A frequently used and clinically appropriate guideline TREATMENT for post diameter is not to exceed one-third of the Following normal and appropriate endodontic instru- root diameter. It has been determined that when a mentation, teeth can possess less than 1 mm of dentin, root canal is prepared for a post and the diameter is indicating that there should be no further root pre- increased beyond one-third of the root diameter, the paration for the post. When these teeth are encoun- tooth becomes exponentially weaker. Each millimeter tered, it is best to fabricate a post that fits into the increase (beyond one-third of the root diameter) existing morphological form and diameter rather than causes a six-fold increase in the potential for root additionally preparing the root to accept a prefabri- 62 fracture. Based on measuring the root dimensions cated type of post. This characteristic is one of the of 1,500 teeth (125 for each tooth) and using the primary indications for the use of a custom cast post guideline that the post should be one-third of the root and core. One study determined that canines (max- diameter, optimal post diameter measurements have illary and mandibular), maxillary central and lateral been determined to be approximately 0.6 mm for incisors, and the palatal root of maxillary first molars mandibular incisors, 1.0 mm for maxillary central possessed more than 1 mm of dentin after endodontic incisors, maxillary and mandibular canines, and the cleaning and shaping.181 All other teeth had roots 125 palatal root of the maxillary first molar. The with less than 1 mm of remaining dentin following recommended post diameter for the other teeth was endodontic treatment. With the goal of preserving 125 0.8 mm. Another study of 700 teeth recommended 1 mm of remaining dentin lateral to posts, it has been that post diameter should range from 0.7 mm for determined that single-canal maxillary first premolars mandibular incisors to a maximum of 1.7 mm for should have posts that are 0.7 mm in diameter or 102 maxillary central incisors. less.126 Mandibular premolars with oval/ribbon- shaped canals should not be subjected to any prepara- tion of the root canal for a post since it will result in ANATOMICAL/STRUCTURAL LIMITATIONS less than 1 mm of dentin.181 Preparation of the mesial The practitioner who completed the endodontic treat- root canals in mandibular molars and the facial root ment is ideally suited to identify characteristics of the canals in maxillary molars can result in perforation or pulpal chamber, rooted canal(s) anatomy, and com- only thin areas of remaining dentin. Based on the pleted endodontic filling that should be reviewed measurements of residual dentin thickness, it is before placing a post and core. These characteristics recommended that posts not be placed in these roots include the presence and the extent of dentinal craze if possible. lines, identification of teeth where further root pre- paration (beyond that needed to complete endodontic ROOT CURVATURE instrumentation) will result in less than 1 mm of When root curvature is present, post length must be remaining dentin or a post diameter greater than limited so as to preserve remaining dentin, thereby one-third of the root diameter area, information helping to prevent root fracture or perforation. Root regarding areas where the remaining tooth structure curvature occurs most frequently in the apical 5 mm is thin, and the point at which significant root curva- of the root. Therefore, if 5 mm of gutta-percha is ture begins. retained apically, curved portions of the root are usually avoided. As discussed previously under post length, molar posts should not exceed 7 mm in the CRAZE LINES roots because of the potential for perforation due to Cracks in dentin are areas of weakness where further root curvature and the presence of developmental propagation may result in root fracture and tooth loss root depressions. Molar roots are frequently curved (see Chapter 19). The patient should be informed of and the post should terminate at the point where their presence with appropriate chart documentation substantive curvature begins. of crack location. It is prudent to avoid post place- ment, if possible, in favor of a restorative material TYPE OF POST AND CORE core. If a post is required, it should passively fit the canal, and the definitive restoration should entirely Custom Cast Post encompass the cracked area, whenever possible, by For many years, custom cast posts and cores have been forming a ferrule. considered to be the standard of care when restoring 1452 / Endodontics endodontically treated teeth and have historically been made of metal. Gold, silver–palladium, and base metal alloys are the most commonly used metals. For eco- nomic reasons, base metal alloys were introduced as an alternative metal to high-noble alloys. The major dis- advantages of base metal alloys are their manipulation (laboratory and clinical), their hardness, and their unstable chemical structure.182 The degradation of base metal alloys releases substances that could be harmful to the patient.182–184 Silver–palladium alloys were intro- duced as a replacement for gold and base metal alloys. They are relatively easy to manipulate and have many properties similar to those of gold casting alloys.185 However, the castability of silver–palladium alloys was shown to be inferior to that of gold-based alloys.182,186,187 Cast posts and cores can be fabricated by using either a direct or an indirect technique, and several methods have been described for the intraoral fabri- cation of an acrylic resin pattern for a direct post and core.188–192 Prefabricated plastic patterns are com- monly used, and they are relined to fit the post space with an autopolymerizing acrylic resin (Figure 16). The coronal adaptation of the tooth is usually com- pleted by using the same resin, and the core is con- toured intraorally to the desired form. The only dis- Figure 16 Prefabricated plastic patterns commonly used for the direct advantage of this direct technique is the amount of technique method for the intraoral fabrication of an acrylic resin pattern for a cast post and core. chairside time required to perform the procedure. As an alternative, indirect techniques for the fabrication of cast posts and cores have been pro- material indicates that there was no elongation of the posed.193–195 However, this procedure requires meti- impression material upon removal. culous attention to a defined protocol to ensure To make the impression technique easier, prefabri- success. One technique uses a Lentulo spiral instru- cated precision plastic dowels were introduced.196,197 ment to carry an impression material to the apical After the selection of the desired diameter for the aspect of the prepared post space. Since a thin projec- dowel, a corresponding drill is used to prepare the tion of a polymerized impression material can be post space at the appropriate length. The dowel is distorted or torn upon removal from the mouth, then inserted into the prepared canal, picked up in reinforcement of the impression material is required. an impression, and transferred to the dental labora- This reinforcement can be accomplished by using tory for fabrication. several materials such as a plastic pin or a metal wire. A proposed advantage of cast posts and cores is Care must be taken when using plastic pins to ensure their purported ease of removal in case of an endo- that they are not slightly flexed by placement into a dontic retreatment.198–200 In addition, several long- curved canal or through contact with the impression term clinical studies have reported high success rates tray, thereby allowing a return to their original form with cast post and cores.50,201 upon impression removal with some resulting distor- tion.Theuseofaportionofasafetypinisanexcel- lent material so long as it is made of spring steel, Prefabricated Posts thereby preventing flexion. A bendable metal pin Prefabricated posts have become quite popular and a can be distorted upon impression removal. Complete wide variety of systems are available: parallel-sided or seating of a section from a safety pin until it contacts tapered, smooth or serrated, passive (cement/bonded) the gutta-percha is recommended. Upon removal of or active (threaded), or combinations of these.202–204 the impression from the mouth, the presence of the Threaded posts depend primarily on engaging the metal pin at the apical extension of the impression tooth—either through threads formed in the dentin as Chapter 40 / Restoration of Endodontically Treated Teeth / 1453

Figure 17 Surface texture of a carbon fiber-reinforced epoxy resin dowel (SEM magnification: Â1000). the post is screwed into the root or through threads previously ‘‘tapped’’ into the dentin. The majority of these posts are metallic. Recently, in response to a need for tooth-colored posts, several nonmetallic posts such as carbon fiber epoxy resin, zirconia, glass fiber- reinforced (GFR) epoxy resin, and ultrahigh strength Figure 18 Available shapes of carbon fiber-reinforced epoxy resin polyethylene fiber-reinforced (PFR) posts are available posts. and early data indicates that they can be acceptable alternatives to metallic posts. The carbon fiber-reinforced (CFR) epoxy resin ferent types of fiber posts. They found that only Com- post system was developed in France in 1988 by Duret posipost and Snowpostposts had uniform radiopacity. and Renaud205–207 and first introduced in Europe in Finger et al.220 examined the radiopacity of seven fiber- the early 1990s.208–210 The matrix for this post is an reinforced resin posts compared with a titanium post. epoxy resin reinforced with unidirectional carbon Compared to other posts, they found CFR posts had an fibers parallel to the long axis of the post. The fibers acceptable radiopacity. are 8 mm in diameter and uniformly embedded in the The posts are available in different shapes: double epoxy resin matrix. By weight, the fibers comprise cylindrical with conical stabilization ledges or conical 64% of the post and are stretched before injection of shapes (Figure 18). The surface texture of the post the resin matrix to maximize the physical properties may be smooth or serrated. Studies have indicated of the post (Figure 17).205,211,212 The post is reported that serrations increased mechanical retention to absorb applied stresses and distribute these stresses although the smooth post also bonded well to adhe- along the entire post channel.213 The bulk of the sive dental resin.217,221 The post has a surface rough- carbon fibers is made from polyacrylonitrile by heat- ness of 5 to 10 mm to enhance mechanical adhesion of ing it in air at 200 to 250C and then in an inert the autopolymerizing luting material, and the post atmosphere at 1200C. This process removes hydro- appears to be biocompatible based on cytotoxicity gen, nitrogen, and oxygen, leaving a chain of carbon tests.216,222 atoms and forming carbon fibers.214 Several studies indicate that CFR posts exhibit ade- The CFR post has been reported to exhibit high quate physical properties compared to metal fatigue strength, high tensile strength, and a modulus posts.212,215,223,224 In a retrospective study over 4 years, of elasticity similar to dentin.208,211,215–218 The post Ferrari et al.223 indicated that the Cosmopost system was originally radiolucent; however, a radiopaque post was superior to the conventional cast post and is now available. Radiopacity is produced by placing core system. King and Setchell215 and Duret et al.212 traces of barium sulfate and/or silicate inside the post. evaluated the physical properties (fracture resistance Mannocci et al.219 examined radiographically five dif- and modulus of elasticity) of CFR posts and both 1454 / Endodontics reported that these posts are stronger than prefabricated time of 3.8 years of clinical service. In a prospective metal posts. study of 59 CFR posts, Glazer et al.243 indicated Contrasting results were reported by Sidoli et al.225 that these posts did not fracture and there was a in an in vitro study. They found that CFR posts 7.7% absolute failure rate. Another retrospective exhibited inferior strength when compared with study244 of 1,304 CFR posts followed from 1 to 6 metallic posts. Similar results were also obtained by years found a 3.2% failure rate that was attributed Purton and Love226 and Asmussen et al.227 to debonding during removal of temporary crowns Martinez-Insua et al.228 studied the fracture resis- and periapical lesions. Hedlund et al.245 studied the tance of teeth restored with CFR posts and cast posts. clinical performance of 65 CFR posts for an average They reported a significantly higher fracture threshold of 2.3 years of clinical service and found a 3% for cast post and cores. A clinical evaluation of CFR failure rate. In a retrospective study of 64 CFR posts suggested that these posts did not perform as well posts, Segerstro¨metal.246 found that nearly 50% as conventional cast post and cores.229 However, the of the CFR posts were lost after a mean time of 6.7 results of this study must be interpreted with caution years. because of the relatively small sample size (27 teeth) Should fracture of a CFR post occur, a potential used in this study. advantage is the relative ease of removal from the post Multiple studies indicate that there is a decrease in space compared with metal posts. A removal kit has the strength of CFR posts after thermocycling and been suggested for this procedure and the latter is cyclic loading.230–233 In addition, contact of the post recommended as a single use only item.247–251 with oral fluids reduced their flexural strength Glass fiber-reinforced epoxy resin posts The high values.222–234 demand for esthetic restorations and all-ceramic In two studies, results indicated no significant dif- crowns led to the development of a varity of tooth- ference among a CFR post, cast post and cores, and colored post systems as an alternative to metal and metal posts when restoring mandibular incisor teeth. CFR posts. No differences were noted in the mode or state of The GFR epoxy resin post is made of glass or silica fracture observed.235,236 fibers (white or translucent). Glass fiber posts can be Multiple in-vitro studies have reported that CFR made of different types of glasses: electrical glass, posts are less likely to cause fracture of the root at high-strength glass, or quartz fibers (Figure 19).233,252 failure. The mode of failure of teeth restored with The commonly used fibers are silica-based (50% to 253 CFR posts in these studies was more favorable to the 70% SiO2), in addition to other oxides. remaining tooth structure.170,215,225,228,237–241 However, despite all these advantageous properties, in vivo applications of the CFR post should be ques- tioned. When the ferrule is small or absent in an endodontically treated tooth restored with a CFP post, loads may cause the post to flex causing a micromovement of the entire core. The cement seal at the margin of the crown can be compromised, accompanied by microleakage of oral bacteria and fluids. As a result, secondary caries may develop in the space and may not be easily detected.241 The short-term clinical studies of CFR posts appear promising but some of the longer-term stu- dies report higher failure rates. Wennstro¨m209 restored 173 teeth with CFR posts and reported two failures after a period of 3 to 4 years. A short- term retrospective study of 236 teeth treated 2 to 3 years previously reported no failures of the 242 223 posts. Ferrari et al. studied 100 CFR posts Figure 19 Surface texture of a glass fiber-reinforced epoxy resin post and reported a failure rate of 3.2% after a mean (SEM magnification: Â250). Chapter 40 / Restoration of Endodontically Treated Teeth / 1455

post.261,262 Other studies indicated that there was a good adhesive bond between the GFR post and com- posite resin cements.261,263,264 The bonding of the core to the post can be improved by treating the post with airborne-particle abrasion.265 Similar results were obtained by treating the surface of the post with hydrogen peroxide and silane or hydrofluoric acid and silane.266,267 During fatigue loading, a composite resin core bonded to a GFR post provided signifi- cantly stronger crown retention than cast gold posts and cores and titanium posts with composite resin cores.171 Similar to CFR posts, multiple studies have shown Figure 20 Available shapes and designs for glass fiber-reinforced epoxy resin posts. that GFR posts are less likely to cause fracture of the root at failure.232,268–270 Themodeoffailureofteeth restored with CFR posts in these studies was more favorable to the remaining tooth structure. However, The GFR post is available in different shapes: cylind- studies have discussed the importance of the presence rical, cylindroconical, or conical shape (Figure 20). An of a ferrule effect in achieving a high success in vitro assessment of several GFR post systems indi- rate.170,173,174,271 Malferrari et al.270 restored 180 teeth cated that parallel-sided GFR posts are more retentive with GFR posts and reported no post, core, or root than tapered GFR posts.254 fracture after 30 months of service. Naumann et al.272 The composition of the glass fibers in the matrix found that the survival rate of parallel-sided and tends to play an important role in the strength of the tapered GFR posts was similar. post. Newman et al.232 compared the fracture resis- Polyethylene fiber-reinforced posts (PFR) are made tance of two GFR posts containing different weight of ultrahigh molecular weight polyethylene-woven percentages of glass fibers. They found that the higher fiber ribbon (Ribbond, Ribbond Inc., Seattle, WA). content of glass fibers in the post contributed to the They are not posts and cores in the traditional sense. greater strength displayed by the tested post. The post is a polyethylene-woven fiber ribbon that is The GFR post has been reported to exhibit high coated with a dentin bonding agent and packed into fatigue strength, high tensile strength, and a modulus the canal, where it is then light polymerized in posi- of elasticity closer to dentin than that of CFR tion.273–275 The Ribbond material has a three- posts.218,227,255 The GFR post is as strong as the CFR dimensional structure due to either a leno weave or post and approximately twice as rigid.256 a triaxial architectural design. These designs are com- The flexural strength of GFR posts is not related to posed of a great number of nodal intersections that the type of glass fiber used. Galhano et al.218 evaluated prevent crack propagation and provide a mechanical the flexural strength of carbon fiber, quartz fiber, and retention for the composite resin cement. When PFR glass fiber posts. They found that the posts behaved posts were compared with metal posts in the labora- similarly because of the same concentration and type tory, the fiber-reinforced posts reduced the incidence of the epoxy resin used to join the fibers together. of vertical root fracture. The addition of a small-size Pfeiffer et al.257 evaluated, in vitro, the yield strength prefabricated post to the PFR post increased the of GFR post, titanium, and zirconia posts. They found strength of the post-and-core complex. However, the that the yield strength was significantly higher for the strength of the PFR post did not approach that of a zirconia and titanium posts when compared with GFR cast metal post and core.273 posts. When compared with other fiber-reinforced com- Several studies have determined that there is a posite post systems, the PFR posts were also found to decrease in the strength (about 40%) of GFR posts protect the remaining tooth structure.232 These results after thermocycling and cyclic loading. In addition, may be attributed to the manufacturer’s recommen- contact of the post with oral fluids (short- and long- dations of not enlarging the root canals, not removing term) reduced theird flexural strength.230,233,258–260 undercuts present in the root canal, and forming a 1.5 Two studies indicated that the tensile bond strength to 2mm crown ferrule. The presence of a large volume between the composite resin core material and the of core material and a sufficient dentin bonding area GFR post is less than that developed with a titanium coronally seems to greatly affect the mean load-to-failure 1456 / Endodontics value of PFR posts.232 Eskitascioglu et al.276 evalu- room temperature. This mechanism is known as ated two post and core systems using a fracture transformation toughening.281,287,291–293 strength test and a finite element analysis. They The type of zirconia used for dental posts is com- found that stress accumulated along the cervical posed of TZP with 3 mol% yttrium oxide (Y2O3) and region of the tooth and along the buccal bone. is called YTZP (yttria-stabilized tetragonal polycrys- Minimal stress was recorded within the PFR post talline zirconia).281,294 YTZP is composed of a dense system. They suggested that the PFR post could be fine-grained structure (0.5 mm average diameter) that advantageous for the restoration of teeth with apical provides the post with toughness and a smooth sur- resection. face.292,294,295 Newman et al.232 compared the effect of three The zirconia post is extremely radiopaque, biocom- fiber-reinforced composite post systems on the frac- patible, possesses high flexural strength and fracture ture resistance of endodontically treated teeth. They toughness, and may act similar to steel.287–291,296–304 found that when PFR posts were placed in narrow In addition, the post has a low solubility301 and is not canals, they performed better than GFR posts. They affected by thermocycling.230 The post is available in a suggested the PFR post be formed to the shape of the cylindroconical shape (Figure 21). canal. The zirconia post has a smooth surface configura- The use of PFR posts to restore endodontically tion with no grooves, serrations, or roughness to treated teeth appears to be a promising alternative to the stainless steel and zirconia dowel posts with respect to microleakage.277 Usumez et al.277 compared in vitro the microleakage of three esthetic, adhesively luted post systems with a conventional post system. They found that the PFR posts and the GFR posts exhibited less microleakage compared with zirconia posts. Zirconia posts The trend toward the use of all-ceramic crowns has encouraged manufacturers to explore the development of all-ceramic posts.278–281 A metal-free post avoids discoloration of tooth structure that can occur with metal posts and produces optical properties comparable to all-ceramic crowns.282–285 Onetypeof all-ceramic post is the zirconia post, composed of zir- conium oxide (ZrO2), an inert material used for a range of applications. Its high fracture toughness, high flexural strength, and excellent resistance to corrosion encour- aged orthopedists to use it at articulation surfaces.286 Studies have suggested that zirconia specimens trans- planted in animals were very stable after long-term aging, and there was no apparent degradation of the specimens.286,287–290 Zirconia (tetragonal zirconium polycrystals, TZP) exhibits phase transformation. Low-temperature degradation of TZP is known to occur as a result of spontaneous phase transformation of tetragonal zir- conia to monoclinic phase during ageing at 130 to 300C possibly within a water environment. It has been reported that this degradation leads to a decrease in strength due to the formation of microcracks accompanying the phase transformation. To inhibit this phase transformation, certain oxides (magne- sium, yttrium, or calcium oxide) are added to fully or partially stabilize the tetragonal phase of zirconia at Figure 21 Available shapes and designs for zirconia posts. Chapter 40 / Restoration of Endodontically Treated Teeth / 1457

posts after different surface treatments. They found that airborne particle-abraded posts exhibited significantly higher resistance to fracture than posts that have been ground with a diamond instrument. The use of heat-pressed glass to form the core instead of composite resin has been suggested.201,299,300 This approach may improve the physical properties of the all-ceramic post and core. When the mechanical properties of zirconia posts were evaluated, it was reported that these posts are very stiff and strong, with no plastic behavior.227,298,299 Pfeiffer et al.257 found that the zirconia post had a significantly higher yield strength compared with tita- nium and GFR posts. Several studies indicated that many commonly used Figure 22 Surface texture of zirconia post (SEM magnification: Â1000). posts exhibit higher fracture resistance than zirconia posts.238,297,317,318 In addition, once they fracture the, irretrievable posts will leave unrestorable roots.170,318 enhance mechanical retention (Figure 22). As a result, Nothdurft et al.319 evaluated the clinical perfor- the zirconia post does not bond well to composite mance of 30 zirconia posts in a short-term retrospec- resins and may not provide the best support for a 261,305–308 307 tive study. They found no signs of failure of these brittle all-ceramic crown. Dietschi et al. posts. However, these results should be analyzed with found that these posts also have poor resin-bonding caution because of the small sample size and a short capabilities to dentin after dynamic loading and ther- follow-up time. mocycling due to the rigidity of the post. In a cyclic loading test performed in a wet environment, Man- nocci et al.239 found that the survival rate of zirconia posts compared with fiber posts was significantly Root Selection for Multirooted Teeth lower. 261,264,308,309 In vitro studies indicated that the smooth PREMOLARS surface configuration of untreated zirconia posts leads When posts and cores are needed in premolars, posts to failure at the cement/post interface. The vast majority are best placed in the palatal root of the maxillary of the cement remained in the root and was not premolar and the straightest root of the mandibular attached to the zirconia posts. Wegner and Kern310 premolar. The buccal root could be prepared to a evaluated the bond strength of composite resin cement depth of 1 to 2 mm and to serve as an antirotational to zirconia posts. They found that the long-term bond lock, if needed. strength of the resin composite cement to zirconia posts is weak. Several studies found that acid etching and silanization of zirconia posts does not improve the strength of the resin bond to the zirconia-based material MOLARS because of the lack of or no silica content in the When posts and cores are needed in molars, posts are post.310–313 However, tribochemical silica coating was best placed in roots that have the greatest dentin found to increase the bond strength of the composite thickness and the smallest developmental root depres- resin to the zirconia post.314,315 Oblak et al.316 com- sions. The most appropriate roots (the primary roots) pared the fracture resistance of prefabricated zirconia in maxillary molars are the palatal roots and in 1458 / Endodontics

CORONAL TOOTH PREPARATION Restoration of endodontically treated teeth must be a team effort between the endodontist and the dentist responsible for the coronal restoration, requiring two- way communication. If it can be co-coordinated, the first step in the fabrication of a post and core should ideally be preparation of the coronal tooth structure (Figure 24) for the type of definitive restoration that will be placed (all-metal crown, metal ceramic crown, all-ceramic crown). This procedure will help in deter- mining the structure of the post–core fabrication. Each type of restoration requires different amounts of tooth reduction, and the form of the tooth pre- paration varies considerably. By preparing the coronal tooth structure first, the structural integrity of remaining dentin and enamel can be assessed. When the remaining peripheral tooth structure is very thin Figure 23 Placement of ParaPost and restorative material core in a and would likely not possess sufficient strength to molar. A, Endodontic treatment completed. B, Provisional restorative resist occlusal forces transmitted through the crown material in the pulpal chamber has been removed and gutta-percha to the tooth, the thin structure is removed and removed from the distal root canal. C, Post space formed with a drill. replaced as part of the core. This order of procedure D, Trial placement of the post. E, The post has been shortened and also establishes morphological borders that can be cemented. A restorative material core has been formed. F, The tooth used to guide core fabrication so that it is confluent with core has been prepared, an impression made, and the definitive crown cemented. G, If there is an extended time delay between place- with the surrounding tooth structure and possesses ment of the core and preparation of the tooth for a crown, the core can the desired tooth preparation form. be built to full tooth contour to serve as the interim restoration. PULPAL CHAMBER PREPARATION mandibular molars are the distal roots (Figure 23). The facial roots of maxillary molars and the mesial Treatment materials present in the pulpal chamber root of mandibular molars should be avoided if at all following endodontic treatment (restorative materials possible. If these roots must be used in addition to the primary roots, then the post length should be short (3 to 4 mm) and a small-diameter instrument should be used (no larger than a No. 2 Peeso instrument that is 1.0 mm in diameter). When 7-mm long posts were placed in the mesial root of mandibular molars, 20 of the 75 tested teeth had only a thin layer of remaining dentin or were perforated.90

Type of Definitive Restoration It is important to know the type of single crown or retainer (all-metal, all-ceramic, metal ceramic) that will be used as the definitive restoration for each endodontically treated tooth that requires a post and Figure 24 Coronal tooth preparation. The existing crown has been core. This knowledge permits the tooth to be reduced removed on an endodontically treated tooth. Initial reduction of the in accordance with the reduction depths and form tooth has been completed to permit assessment of integrity of remaining recommended for each type of crown/retainer. coronal tooth structure. Chapter 40 / Restoration of Endodontically Treated Teeth / 1459

residual dentin. For this reason, it may be prudent to prepare the root canal for a post as a continuation of the endodontic treatment. If the canal has not been prepared for a post as part of the endodontic treatment process, it is necessary to remove the filling material using either a warm endo- dontic hand instrument or a slow-speed rotary instrument such as a Gates Glidden drill (Dentsply International, Tulsa, OK) or a Peeso instrument (Dentsply International). If a warm hand instrument is used, it is advisable to place a rubber dam so as to prevent aspiration or swallowing of the hand instru- ment should it be dropped. Successful use of rotary instruments is related to initially using a small-diameter instrument (one that Figure 25 Pulp chamber preparation. Rotary instrument being used to remove provisional material. removes only the filling material without dentin removal). This small-diameter instrument is used to removesmallverticalincrements(1to2mm)ofthe sealing the coronal access and gutta-percha) are root canal filling material. After each vertical incre- removed by using rotary instruments (Figure 25). If ment is removed, a visual inspection should be made a prefabricated post is cemented into a root canal and to verify that the endodontic filling material is cen- a restorative material core built around the post, tered in the post preparation. The incremental root morphological undercuts present in the pulpal cham- canal filling removal is continued until the appro- ber should be retained for core retention. If a custom priate length is established (Figure 26). Post prepara- cast post and core is fabricated, then pulpal chamber tion length is determined using a periodontal probe. undercuts must be either blocked out with a definitive Remaining gutta-percha length is evaluated by com- cement or a restorative material that is bonded to the paring periodontal probing depths with landmarks tooth or the undercut eliminated by removing the on the postendodontic radiograph and by making a tooth structure. If removing the undercut through radiograph of the prepared post space. After the tooth preparation would result in substantive tooth length is established, any required increases to the structure removal that weakens the tooth, then block- post diameter are performed using incrementally ing out the undercut is the treatment of choice. larger rotary instruments or hand files. ROOT CANAL PREPARATION The individual who completed the root canal is ideally suited to prepare the root canal, being the one that is Preparation for Overdentures most knowledgeable regarding root curvatures and ‘‘The overdenture is a complete denture supported by areas where no further root preparation should retained teeth and the residual alveolar ridge.’’320 be performed because it will result in areas of thin Because the ‘‘retained teeth’’ are shortened, contoured,

A BC

Figure 26 Root canal preparation. A, Rotary instrument being used to prepare post space in the root canal. Note the rubber ring around the instrument to identify the appropriate apical extension of the post preparation. B, Periodontal probe being used to measure post space depth. C, Post space preparation completed. 1460 / Endodontics and altered to be covered, root canal therapy is almost always required. In 1969, Lord and Teel321 coined the term ‘‘overdenture’’ and described the com- bined endodontic–periodontic–prosthodontic techni- que applied thereto. As early as 1916, however, Prothero had referred to the use of root support, stating, ‘‘Often- times two or three widely separated roots or teeth can be utilized for supporting a denture.’’322 It should also be noted that much earlier, in 1789, George Washington’s first lower denture, constructed of ivory by John Green- wood, retained a mandibular left premolar.323 Retaining roots in the alveolar process is based on the proven observation that so long as the root remains, the bone surrounding it remains (Figure 27). This overcomes the age-old prosthetic problem of Figure 28 Mirror view of four retained abutments providing ideal ridge resorption. Ideally, then, retaining four teeth, support for an overdenture. Note the properly contoured and polished two molars, and two canines, one each at the four copings protecting the abutment teeth. divergent points of an arch, should ensure prosthesis balance and long ‘‘life’’ to a complete overdenture (Figure 28). Unfortunately, patients requiring pros- INDICATIONS AND ADVANTAGES theses seldom present just these ideal conditions. The indications for overdentures include the psychic Decisions regarding which teeth to retain usually support some patients receive from not being totally focus on keeping some of the healthiest teeth located edentulous. Even more important are the preservation in strategic positions such as canines. One situation to of the alveolar ridge and the shielding of the ridge be warned against, however, is the diagonal cross-arch from stress provided by firm abutment teeth. It arrangements, a molar abutment on one side, for should also be noted that occlusal vertical dimension example, and a canine on the opposite side. The rock- is better preserved if ridge height is maintained. A ing and torquing action set up by this arrangement bonus to all these advantages is the support, the often leads to problems and loss of one or both abut- stability, and retention derived from abutments. All ments. The molar abutment alone is preferable to the these advantages are heightened in the young patient diagonal cross-arch situation. who must wear dentures for years to come. If the selected abutment tooth is reduced to a short Complete overdentures should be considered for rounded or bullet-shaped structure and literally ‘‘tuck- virtually every patient for whom complete mouth ing’’ the abutments inside the denture base, the extractions are being considered. Sometimes, certain crown–root ratio of the tooth is vastly improved, espe- teeth can be periodontally and endodontically treated cially when periodontally involved teeth have lost some and retained as abutments to support an overdenture. alveolar support. As a shortened tooth, however, it will The overdenture better resists occlusal forces than the serve admirably as an abutment for an overdenture. totally tissue-supported complete denture. Some attri- bute this resistance to the proprioceptive sensory mechanism derived from the retained roots under the overdenture. Application of the overdenture to removable partial denture support is also indicated, even if only one abutment is available.

CONTRAINDICATIONS The overdenture technique is contraindicated when remaining alveolar support is so lacking that no tooth can be retained for very long. This condition often supports the use of endosseous root-form implants to Figure 27 Dramatic demonstration of alveolar bone remaining around support and retain a prosthesis. Overdentures are also retained canines but badly resorbed under complete maxillary and contraindicated if the remaining natural teeth are posterior mandibular removable partial dentures. adequate to restore the mouth with fixed partial Chapter 40 / Restoration of Endodontically Treated Teeth / 1461 dentures or removable partial dentures. The overden- saved, with incisors the second choice. It is especially ture technique should be no pathway to expediency. important to save mandibular teeth because of diffi- culties encountered in retaining mandibular dentures. ABUTMENT TOOTH SELECTION Even saving a single tooth, a molar in particular, may contribute greatly to long-term denture success. ‘‘A healthy abutment tooth for an overdenture must have minimal mobility, a manageable sulcus depth, TECHNIQUE and an adequate band of attached gingiva.’’320 If these prerequisites are lacking, the pocket depth can be After the selection of the most favorable abutment reduced and attached gingiva developed by using teeth, the key to successful overdenture fabrication is appropriate periodontal procedures. simplicity of technique (Figure 29). If an immediate denture is to be placed, the endodontic therapy, extractions, and periodontal treatment can some- ABUTMENT TOOTH LOCATION times be done at the denture placement appoint- Ideal teeth to retain are those whose occlusal forces ment. The crowns of these teeth are amputated 3 wreak greatest destruction upon the ridges. Opposite a to 4 mm above the gingival level and the endodontic natural dentition, the canine teeth are ideal to retain. procedure completed. The coronal 5 to 6 mm of the In edentulous patients, the anterior portion of the gutta-percha restoration is removed, the preparation arches is particularly susceptible to resorption, so is undercut, and a well-condensed amalgam filling is canines and premolars are again the first choice to be placed to restore and help seal the canal obturation.

A B

C

E D

Figure 29 Preparing an overdenture abutment. A, The crown is amputated 3 to 4 mm above the gingival level. B, The endodontic procedure is started. C and D, An amalgam restoration is placed in the coronal 5 to 6 mm. E, In preparation for fitting the prosthesis, the abutments are shaped and polished. 1462 / Endodontics

Figure 31 Soft, autopolymerizing acrylic resin fills the depression pre- pared in the denture to receive the abutment. This may be replaced Figure 30 Improperly contoured overdenture abutments. Square edges whenever necessary. invite grip by overdenture and torquing action. Prominent buccal contour and extra height comprise the contour of the overdenture. Courtesy of The denture is relieved over the abutments and Dr. David H. Wands. adaptation is achieved between the denture base and edentulous ridge tissues without touching the abut- ment teeth. It is then adapted to the abutment teeth At this time as well, the abutments should be shaped by using a small amount of autopolymerizing acrylic to rise 2 to 3 mm above the tissue, and be rounded resin (Figure 31). This proper relationship of denture or bullet-shaped with a slope back from the labial to to tissue and tooth is important for denture stability accommodate the denture tooth to be set above it. and to keep the stresses on the teeth within physiolo- They should then be highly polished. The abutments gical limits. must not be too short or the tissue will grow over Some overdenture abutment teeth may not need them as a ‘‘lawn grows over a sidewalk’’;320 nor root canal therapy because they are so abraded that should they be too long, compromising the denture the pulp has receded to a level where the tooth contour and placing greater stress on the supporting only needs shortening, contouring, and polishing teeth (Figure 30). (Figure 32). This technique simplifies the treatment and reduces the cost to the patient.

Figure 32 A, Teeth with vital, receded pulps but severe abrasion can be ideal overdenture abutments. B, Incisor overdenture abutment not requiring therapy owing to pulp recession. The calcified pulpal area should be carefully explored. Courtesy of Dr. David H. Wands. Chapter 40 / Restoration of Endodontically Treated Teeth / 1463

Figure 33 Rather typical neglect by many denture patients. A, Caries and periodontal disease forecast probable lack of future patient cooperation. B, Mirror view of lingual gingiva of two possible overdenture abutments. Because it is virtually impossible to develop attached gingiva in the lingual area, the use of these teeth as abutments is contraindicated. Courtesy of Dr. David H. Wands.

If the abutment teeth are periodontally involved or canal. Other challenges related to the use of endodon- are not surrounded by a good collar of attached tically treated teeth included wear of the dentin and gingiva, periodontal therapy will be required to cor- the need for auxiliary prosthesis retention. rect these aberrations. POSSIBLE SOLUTIONS TO THE PROBLEMS PROBLEMS Quite naturally the prime solution to the caries– A number of problems have arisen with overdentures, periodontal problem is better patient cooperation in most of them related to poor patient selection and lack home care. Fluoride gels should regularly be placed in the ‘‘well’’ of the dentin base where the abutments are of patient cooperation. The most serious problems are 326,327 associated with dental caries and periodontal disease. located to remineralize the dentin. This, of It must be remembered that throughout their lives, candidates for complete dentures are those who have usually been neglectful of their teeth and supporting structures and have a history of extensive dental dis- ease (Figure 33). In recommending overdentures, there is some risk. The patients’ habits must change and they must become motivated and adept at oral hygiene to retain the vestiges of their dentition. That some do not, should come as no surprise (Figure 34). The importance of good home care must be empha- sized to the overdenture patient and is a critical factor in long-term success. In a longitudinal study, Ettinger and Qian324,325 evaluated the differences in people who experienced postprocedural problems with over- dentures and compared them with people who had no problems for the duration of the study. They found that most of the failures could have been prevented by better oral hygiene. The most common problem was the development of periradicular problems around Figure 34 Two-year recall reveals advanced caries and periodontal endodontically treated teeth because of recurrent car- disease of abutments. The patient did not remove the denture for days ies causing the loss of the restoration sealing the root at a time. Courtesy of Dr. David H. Wands. 1464 / Endodontics

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Int J Prosthodont 2001;14:141–5. fiber-based posts. J Endod 2005;31:209–11. 236. Isidor F, O¨ dman P, Brøndum K. Intermittent loading of 219. Mannocci F, Sherriff M, Watson TF. Three-point bending teeth restored using prefabricated carbon fiber posts. Int J test of fiber posts. J Endod 2001;27:758–61. Prosthodont 1996;9:131–6. Chapter 40 / Restoration of Endodontically Treated Teeth / 1471

237. Dean JP, Jeansonne BG, Sarkar N. In vitro evaluation of a 255. Bae JM, Kim KN, Hattori M, et al. The flexural properties of carbon fiber post. J Endod 1998;24:807–10. fiber-reinforced composite with light-polymerized polymer matrix. Int J Prosthodont 2001;14:33–9. 238. Cormier CJ, Burns DR, Moon P. In vitro comparison of fracture resistance and failure mode of fiber, ceramic, and 256. Triolo PT, Trajtenberg C, Powers JM. Flexural properties conventional post systems at various stages of restoration. J and bond strength of an esthetic post. [abstract 3538] J Dent Prosthodont 2001;10:26–36. Res 1999;78:548. 239. Mannocci F, Ferrari M, Watson TF. Intermittent loading of 257. Pfeiffer P, Schulz A, Nergiz I, Schmage P. Yield strength of teeth restored using quartz fiber, carbon-quartz fiber, and zirconia and glass fibre-reinforced posts. J Oral Rehabil zirconium dioxide ceramic root canal posts. J Adhes Dent 2006;33:70–4. 1999;1:153–8. 258. Vallittu P. 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J Compos Mater 1995;29:852–67. spective study of 236 patients with teeth restored by carbon 261. Al-harbi F, Nathanson D. In vitro assessment of retention of fiber-reinforced epoxy resin posts. J Prosthet Dent four esthetic dowels to resin core foundation and teeth. J 1998;80:151–7. Prosthet Dent 2003;90:547–55. 243. Glazer B. Restoration of endodontically treated teeth with 262. Coelho Santos G Jr, El-Mowafy O, Henrique Rubo J. Dia- carbon fiber posts- a prospective study. J Can Dent Assoc metral tensile strength of a resin composite core with non- 2000;66:613–18. metallic prefabricated posts: an in vitro study. J Prosthet 244. Ferrari M, Vichi A, Mannocci F, Mason PN. Retrospective Dent 2004;91:335–41. study of the clinical performance of fiber posts. Am J Dent 263. Le Bell AM, Lassila LVJ, Kangasniemi I, Vallittu PK. Bond- 2000;13(Spec. No.):9B–13B. ing of fibre-reinforced composite post to root canal dentin. J 245. Hedlund SO, Johansson NG, Sjo¨gren G. A retrospective Dent 2005;33:533–9. study of pre-fabricated carbon fiber root canal posts. J Oral 264. Hedlund SO, Johansson NG, Sjo¨gren G. Retention of pre- Rehabil 2003;30:1036–40. fabricated and individually cast root canal posts in vitro. Br 246. Segerstro¨m S, Astback J, Ekstrand KD. A retrospective long Dent J 2003;195:155–8. term study of teeth restored with prefabricated carbon fiber 265. Balbosh A, Kern M. Effect of surface treatment on retention of reinforced epoxy resin posts. Swed Dent J 2006;30:1–8. glass-fiber endodontic posts. J Prosthet Dent 2006;95:218–23. 247. Gesi A, Magnolfi S, Goracci C, Ferrari M. Comparison of two 266. Vano M, Goracci C, Monticelli F, et al. The adhesion techniques for removing fiber posts. J Endod 2003;29(9):580–2. between fibre posts and composite resin core: the evaluation 248. De Rijk WG. Removal of fiber posts from endodontically of microtensile bond strength following various surface che- treated teeth. Am J Dent 2000;13 (Spec. 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Composite materials: science and engineering. different post and core restorations. Dent Mater J 2nd ed. New York: Springer-Verlag; 1998. 2005;24:225–31. 254. Teixeira ECN, Teixeira FB, Piasick JR, Thompson JY. An in 270. Malferrari S, Monaco C, Scotti R. Clinical evaluation of teeth vitro assessment of prefabricated fiber post systems. J Am restored with quartz fiber-reinforced epoxy resin posts. Int J Dent Assoc 2006;137:1006–12. Prosthodont 2003;16:39–44. 1472 / Endodontics

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J Dent 1998;79:702–5. Mater Sci 1978;13:1464–70. 280. Zalkind M, Hochman N. Direct core buildup using a pre- 296. Soares CJ, Mitsui FH, Neto FH, et al. Radiodensity evalua- formed crown and prefabricated zirconium oxide post. J tion of seven root post systems. Am J Dent 2005 Prosthet Dent 1998;80:730–2. Feb;18(1):57–60. 281. Ahmad I. Yttrium-partially stabilized zirconium dioxide 297. Rosentritt M, Fu¨rer C, Behr M, et al. Comparison of in vitro posts: an approach to restoring coronally compromised fracture strength of metallic and tooth-coloured posts and teeth. Int J Periodont Restor Dent 1998;18:454–65. cores. J Oral Rehabil 2000;27:595–601. 282. Sorensen JA, Mito WT. Rationale and clinical technique for 298. Taira M, Nomura Y, Wakasa K, et al. Studies on fracture esthetic restoration of endodontically treated teeth with toughness of dental ceramics. J Oral Rehabil 1990;17:551–63. Cosmopost and IPS Empress post system. QDT 1998;81–90. 299. Hochman N, Zalkind M. New all-ceramic indirect post-and- 283. Michalakis KX, Hirayama H, Sfolkos J, Sfolkos K. Light trans- core system. J Prosthet Dent 1999;81:625–9. mission of posts and cores used for the anterior esthetic region. 300. Dilmener FT, Sipahi C, Dalkiz M. Resistance of three new Int J Periodont Restor Dent 2004;24:462–9. esthetic post-and-core systems to compressive loading. J 284. Carossa S, Lombardo S, Pera P, et al. Influence of posts and Prosthet Dent 2006;95:130–6. cores on light transmission through different all-ceramic 301. Piconi C, Maccauro G. Zirconia as a ceramic biomaterial. crowns: spectrophotometric and clinical evaluation. Int J Biomaterials 1999;20:1–25. Prosthodont 2001;14:9–14. 302. Kakehashi Y, Luthy H, Naef R, et al. A new all-ceramic post 285. Ottl P, Hahn L, Lauer HCh, Fay M. Fracture characteristics and core system: clinical, technical, and in vitro results. Int J of carbon fibre, ceramic and non-palladium endodontic post Periodont Restor Dent 1998;18:586–93. systems at monotonously increasing loads. J Oral Rehabil 2002 Feb;29(2):175–83. 303. Koutayas SO, Kern M. All-ceramic posts and cores: the state of the art. Quintessence Int 1999;30:383–92. 286. Cales B, Stefani Y, Lilley E. Long-term in vivo and in vitro aging of a zirconia ceramic used in orthopaedy. J Biomed 304. Heydecke G, Butz F, Hussein A, Strub JR. Fracture strength Mater Res 1994;28:619–24. after dynamic loading of endodontically treated teeth Chapter 40 / Restoration of Endodontically Treated Teeth / 1473

restored with different post-and-core systems. J Prosthet composite-resin bond strength of zirconia posts: an in vitro Dent 2002;87:438–45. study. J Prosthet Dent 2006;95:224–9. 305. Perdigao J, Geraldeli S, Lee IK. Push-out bond strength of 316. Oblak C, Jevnikar P, Kosmac T, et al. Fracture resistance and tooth-colored posts bonded with different adhesive systems. reliability of new zirconia posts. J Prosthet Dent Am J Dent 2004;17:422–6. 2004;91:342–8. 306. Cohen BI, Pagnillo MK, Newman I, et al. Retention of core 317. Mitsui FH, Marchi GM, Pimenta LA, Ferraresi PM. In vitro material supported by three post head designs. J Prosthet study of fracture resistance of bovine roots using different Dent 2000;83:624–8. intraradicular post systems. Quintessence Int 2004;35:612–16. 307. Dietschi D, Romelli M, Goretti A. Adaptation of adhesive 318. Akkayan B, Gu¨lmez T. Resistance to fracture of endodonti- posts and cores to dentin after fatigue testing. Int J Prostho- cally treated teeth restored with different post systems. J dont 1997;10:498–507. Prosthet Dent 2002;87:431–7. 308. Baba NZ. The effect of eugenol and non-eugenol endodontic 319. Nothdurft FP, Pospiech PR. Clinical evaluation of pulpless sealers on the retention of three prefabricated posts cemen- teeth restored with conventionally cemented zirconia posts: ted with a resin composite cement [thesis]. Boston, MA: a pilot study. J Prosthet Dent 2006;95:311–14. Boston University; 2000. 320. Lord JL, Teel S. The overdenture: Patient selection, use of 309. Gernhardt CR, Bekes K, Schaller HG. Short-term retentive copings, and follow-up evaluation. J Prosthet Dent 1974; values of zirconium oxide posts cemented with glass iono- 32:41–51. mer and resin cement: an in vitro study and a case report. 321. Lord JL, Teel S. The overdenture. Dent Clin North Am Quintessence Int 2005;36:593–601. 1969;13:871. 310. Wegner SM, Kern M. Long-term resin bond strength to 322. Prothero JH. Prosthetic dentistry. 2nd ed. Chicago, IL: Med- zirconia ceramic. J Adhes Dent 2000;2:139–47. icodental Publishing Co.; 1916. pp. 476, 519. 311. Madani M, Chu FCS, McDonald AV, Smales RJ. Effects of 323. Sognnaes RF. America’s most famous teeth. Smithsonian surface treatments on shear bond strengths between a resin 1973;3:47. cement and an alumina core. J Prosthet Dent 2000;83:644–7. 324. Ettinger RL, Qian F. Postprocedural problems in an over- 312. Blixt M, Adamczak E, Linden L, et al. Bonding to densely denture population: a longitudinal study. J Endod 2004; sintered alumina surfaces: effect of sandblasting and silica 30(5):310–14. coating on shear bond strength of luting cements. Int J Prosthodont 2000;13:221–6. 325. Ettinger RL, Qian F. Abutment tooth loss in patients with overdentures. J Am Dent Assoc 2004;135(6):739–46. 313. Ozcan M, Alkumru HN, Gemalmaz D. The effect of the surface treatment on the shear bond strength of luting 326. Shannon IL. Chemical preventive dentistry for overdenture cement to glass-infiltrated alumina ceramic. Int J Prostho- patients. In: Brewer AA, Morrow RM, editors. Overdentures. dont 2001;14:335–9. 2nd ed. St. Louis, MO: CV Mosby Co; 1980. pp. 322–40. 314. Matinlinna JP, Lassila LV, Ozcan M, et al. An introduction 327. Key MC. Topical fluoride treatment of overdenture abut- to silanes and their clinical applications in dentistry. Int J ments. Gen Dent 1980;28:58. Prosthodont 2004;17:155–64. 328. Brewer AA, Morrow RM. Overdenture problems. In: Brewer 315. Xible AA, de Jesus Tavares RR, de Araujo Cdos R, Bonachela AA, Morrow RM, editors. Overdentures. 2nd ed. St. Louis, WC. Effect of silica coating and silanization on flexural and MO: CV Mosby Co; 1980. p. 345. CHAPTER 41

OPERATIONS MANAGEMENT IN ENDODONTIC PRACTICE

MARTIN D. LEVIN

The establishment of any professional practice should insurance and financial manager, and human resource include the development of a vision that promotes (HR) authority.3 excellence in both clinical application and perfor- Clinical excellence is the hallmark of every true mance. With the advent of new technologies such world-class practice. What really matters is adopting as in-office cone beam computed tomography, the an ethical and philosophical level of quality that will emergence of molecular dentistry and medicine, new enable each practice to do the right thing every time. pharmacogenomics, increased dissemination of knowl- Basically, we are in the people business, and people edge on the Internet, and improved electronic com- naturally align with organizations that value integrity, munications, we are at the threshold of a new era in compassion, quality of care, and high standards of patient care. Concurrently, these new technologies, behavior. Only by viewing your organization as a col- improved relationships, and continual improvements lection of interdependent systems and processes that in clinical and experiential performance require good ultimately depend on each employee to reach his or management strategies and, ultimately, financial suc- her full potential will your practice reach the desired cess to create and maintain an outstanding practice. result. As outlined by Abraham Maslow4 over 50 years To accomplish sustainable success, we must not only ago, successful organizations are the ones that genuinely have mastery of the clinical tools of our profession, encourage self-actualization to ensure that people iden- but also possess the skills necessary to run a successful tify and pursue their own unique personal potential. business. To this end, this chapter will highlight operational stra- To remain successful, this vision must include the tegies that focus on creating a vision that will fund sustain- possibility that your practice will have to undergo able success by building a brand-driven culture within both planned changes to implement new procedures your organization that is supported by high-performance and the need to respond to developments over which human systems. the organization will have little or no control. In fact, it has been postulated that today ‘‘more than half of the economic value of dental care is derived from procedures that were not available just 20 years ago.’’1 Choosing How You Want to Practice To train practitioners and employees, upgrade The healthcare industry is a services profession, and technology, and improve client service continually, the as such has different characteristics than companies practice of dentistry requires entrepreneurial training. producing physical goods.5 According to Leonard Dr. Harold Slavkin, former director of the National Berry,6 Distinguished Professor of Marketing at the Institute of Dental and Craniofacial Research (NIDCR), Mays Business School at Texas A&M University, recognized the need for business training when he pro- ‘‘marketing a performance [e.g., medical services] is posed increasing ‘‘the education and training of our not the same as marketing an object . . . In packaged student learners in the field of leadership and manage- goods the emphasis is on differentiating tangib- ment of dental practices.’’2 Today’s endodontist must les through imagery; in services the emphasis is tan- be a clinician, infection control expert, entrepreneur, gibilizing the intangible.’’ To truly understand the

1474 Chapter 41 / Operations Management in Endodontic Practice / 1475 medical services world, Berry spent his sabbatical at A mission statement is a succinct proclamation of the the Mayo Clinic, immersed in day-to-day hospital practice’s purpose for existence. It should include mea- procedures and interactions. He came away with a surable criteria and address such concepts as image, new appreciation for the importance of reliability as customer demographics, target market, and expectations the basis of services marketing excellence. What he is for growth and profitability. Mission statements should saying, essentially, is that you have to do the job right be broad enough to incorporate every service provided the first time, every time because ‘‘who wants to travel and should include the practice’s moral and ethical posi- on an airline whose pilots are usually dependable, [or] tion, geographic and demographic domain, and the be operated on by a surgeon who usually remembers expectations as well as hopes for growth and profitability. where on the body the surgery is to be done?’’ Once a mission statement is adopted by the As a services profession, the delivery of dental care organization, everyone must subscribe to its precepts requires both the provider and the consumer to be or its usefulness will diminish. It is critical that you align present at the same time. This one-on-one relation- your practice with your mission so that every interac- ship gives rise to the potential of real-time customiza- tion between employees and patients builds value. tion, one of the most powerful tools available to Unfortunately, the Workplace 2000 Employee Insight healthcare providers. When you and the patient are Survey, conducted by Tom Terez, author of ‘‘22 Keys to working together to create an agreed-upon result, you Creating a Meaningful Workplace,’’9 found that only can decide how much, or if any, customization will 23% of US workers say that their company’s mission occur, and even whether that customization will occur statement has become a way of doing business. in the front office, the back office, or both. This Visions and missions are usually linked to strate- consultative function should be managed to create gies and goals that are specific, measurable, and short value that satisfies patient and referrer needs. From a term. Once a vision and mission statement has been customer-centered perspective, it means providing adopted and becomes part of the fabric of your what both the patient and referring doctor want, on practice, you can develop an implementation strategy their terms, when and how they want it.7 and a list of annual goals. Finally, adding deadlines Organizations need to establish a strategic framework and a system of measurement will allow you to con- in order to reach their full potential. This framework tinually gauge your progress. consists of (1) a vision for the future, (2) a mission that defines what you are doing now, (3) a step-by-step strategy to clarify your individual situation and develop STRATEGIC PLANNING a program to achieve future objectives, (4) goals and What is a strategy? The word comes from the Greek word action plans that guide day-to-day decision making,8 strategia, meaning ‘‘generalship.’’ While it is difficult to and (5) feedback to see what really works. findagreementonanexactdefinitionofstrategybecause it includes ‘‘thoughts, ideas, insights, experiences, goals, expertise, memories, perceptions and expectations,’’10 VISION AND MISSION STATEMENTS almost everyone can agree that it is about the means to A vision statement is a clearly articulated, future- reach an end, not what those aims are or how they are oriented declaration that articulates what your organi- established. In most successful practices, the leadership zation wants to become. Vision statements range in alone is responsible for assuring that the office’s policies length from a couple of words to several pages; shorter are legitimate and ethical. Strategy, on the other hand, is vision statements tend to be easier to recall and use. the province of both leadership and management, while This statement should resonate with all members tactics are the responsibility of management alone. In of the practice and help them feel proud, excited, other words, determining the goals of an enterprise is and part of something larger than themselves. A mainly a governance issue, while employment of vision should stretch the organization’s capabilities resourcesisthejobofmanagement.Keepinmindthat and image of itself. It should give clarity, shape, and strategy is a changing perspective of what is required to direction to the organization’s future. Do you want obtain the ends that have been specified in policies, and is to be the most technologically advanced specialist in dependent on the actual resultsasmeasuredbybusiness your community? Do you want to achieve a high performance. So strategy and tactics actually bridge the return on your investment? Do you want to be a gap between resources and policy. thought leader, a fee leader, or both? Answers to Two useful techniques to evaluate your future prac- these and other questions will help you create a tice’s potential for success are the SWOT (Strengths, vision for your practice. Weaknesses, Opportunities, and Threats) and PEST 1476 / Endodontics

Table 1 SWOT (Strengths, Weaknesses, Opportunities, and Threats) Anaylysis Strengths: What you do better than the competition Weaknesses: Things that the competition does better than you Opportunities: Trends, changes, and characteristics of your market Threats: Trends and changes associated with your market that may present that may offer opportunities for your business now or in the future your business with problems either now or in the future

This SWOT analysis form measures a business proposition or idea by assessing core issues. Most practices can apply the ideas developed here to understand their current position and help plan future initiatives.

(Political, Economic, Social, and Technological) ana- ending at different times. Most importantly, a goal needs lyses. A SWOT analysis measures a business proposi- to be achievable and challenge the people responsible for tion or idea. Long-range strategic planners often use its accomplishment. SWOT analysis to assess core issues and develop a plan As more employees understand and commit to based on current perceptions (Table 1). Practices can your vision for the practice, it is the job of leadership also benefit by completing a SWOT analysis to evalu- to continually reaffirm it through every available ate a competitor. channel of communication, such as staff meetings, A PEST analysis helps to measure the external or when conversing with co-therapists, and so on. macro-environment that affects all businesses. The According to Lionel Urwick’s11 classic Harvard Busi- most useful analysis for a dental practice will be the ness Review article, 1956, ‘‘There is nothing which rots social and technological analysis portion. The social morale more quickly and more completely than. . .the section is where patients’ and referrers’ demographics, feeling that those in authority do not know their own class structure, education, culture, and attitudes about minds.’’ Once the plan is created, be ready to change healthcare are considered. Technological analysis it. Strategic plans are dynamic, living documents that looks at recent technological developments, their are not a once-a-year project, but can be modified impact on the value-chain structure, cost, and effi- repeatedly as it needs warrant. Strategic planning is ciency. For example, should you consider purchasing one of the key activities that forces organizations to or leasing a cone beam computed tomography scan- focus on the right priorities to foster growth. In the ner, panoramic device, or refer patients needing end, all strategic planning models are goal-based and advanced evaluation to a center with these capabil- rely on clearly defined, understood, and communi- ities? PEST analysis allows for proactive marketing cated action steps. A strategy is not useful, however, if and business development assessment. it is not realized. A Fortune Magazine study has shown that 7 out of 10 CEOs fail because of poor SETTING GOALS execution, not because of bad strategy.12 Goals are plain language statements that describe priorities or actions to be accomplished. Practices PRACTICE MODELS should have a number of goals, each describing a Unlike the practice of medicine, which is becom- desired result toward which your efforts should be ing increasingly complex and business-like, Marjorie directed. Goals set priorities for management and staff Jeffcoat,13 the Morton Amsterdam Dean at the School and establish measurement parameters for evaluating of Dental Medicine, University of Pennsylvania, says success. Goals serve to keep an organization focused that ‘‘dentistry has remained a profession dominated on success and away from activities that tend to dis- by small, independent practices.’’ In fact, Kathleen tract and drain resources. If the goals are accom- Roth, president of the American Dental Association plished, then the business should be a success. (ADA), in a 2007 address to the Small Business Com- Practice goals are generally derived from mission mittee of the U.S. Congress, reported that over 90% of statements and describe how the mission will be accom- practicing dentists are in the private sector and 85% plished, while mission statements describe exactly what of those practitioners operate independent solo prac- needs to be accomplished. A goal should be simple, tices.14 But the need to investigate organizational clearly written, state the conditions that will exist if the alternatives is becoming more urgent with the expec- goal is accomplished, and set action-oriented tasks that tation that there will be a sea change in the way health you want to accomplish in 1 to 3 years. Some business care is organized and funded in the future. While goals will have a 1-year time frame, while others may dentists may continue to practice independently, have longer or shorter time frame. It is not unusual for a other dental practice models will show strong growth practice to have a mix of business goals starting and and evolve as business entities. Chapter 41 / Operations Management in Endodontic Practice / 1477

Armstrong et al.15 have postulated that some prac- intimacy, and high-margin work with demanding tices adhere to the ‘‘service factory model,’’ where patients low cost and standardization predominates, deliver- Armstrong’s service theater approach is similar to ing consistent but standardized service. Conversely, the ‘‘super-norm model’’ proposed by the DTA’s other practices act as ‘‘service theaters,’’ or niche description of emerging practice models, with an practices, where a select clientele undergo pre- emphasis on a customer-centered approach that treats mium-priced procedures that are individualized demanding patients and produces high-margin work. and scripted for maximum effect. Patients choose Practice models will continue to evolve, and some this type of practice if price is no object. They want practices will incorporate elements of several business a high-tech approach, presented with personal atten- forms. One practice model may use technology while tion in an office that rivals the ambiance of a fine also providing cosmetic procedures based on personal hotel. Employees are not just hired here; they are aesthetics and high-end customer service. What does trained to serve as members of a team that values a all of this have to do with your endodontic practice? high-touch, patient-centered experience. Simply put, running a successful practice requires a Other attempts to categorize practice models have powerful vision of where you want to go. been proposed by the Dental Trade Alliance (DTA). Starting a new practice, associating with an estab- Jeffery Lavers,16 Marketing Director of 3M ESPE, lished endodontic practice, or choosing a hybrid says that continual change in the dental marketplace format is the first of many decisions that every endo- is certain and will be influenced by demographics, dontist will have to make when beginning his or her technology, disease patterns, patient behavior, and ser- career. What follows is a short primer on the risks and vice choices and dental workforce. Providers of dental benefits of three employment options. care, for example, will be reduced from their current level of 130,000 full-time equivalent practicing U.S. dentists by more women providers practicing fewer NEW PRACTICE hours and lower numbers of dental school graduates What are the benefits of starting your own practice? than in the past. These factors and an associated You will have complete autonomy in setting practice increase in the U.S. population will continue to decrease policies and making decisions. Every decision, that is, the dentist/population ratio. the selection of particular equipment and designing The DTA has proposed the following emerging treatment protocols, as well as the selection of practice models, which it predicts will provide over employees, will be yours to make. When it is your 60% of all dental services by 2010 (reproduced by business, you dictate the way things are done. The permission of the DTA): scheduling of employee and your own vacations is at your discretion. Then there is personal fulfillment. Ready Access Model—High-process standardiza- Owning and running your own business can be more tion, convenience-oriented, highly flexible operat- satisfying than working for someone else, and many ing systems, focused on a dynamic ‘‘retail’’ service practitioners enjoy the respect they earn from their experience peers for having the courage to go out on their own. When you own your own practice, you may have to Tech Station Model—High level of technical forgo a regular paycheck, but the upside earnings resources, procedural leading edge, ‘‘gee-whiz’’ potential may be greater than any other alternative. experience backed by relatively high-touch patient If these aspects have strong appeal, then starting your communication own practice should be considered. Small Group Model—Well-integrated staff with There are formidable risks to starting your own broad range of scope, seamless teamwork of staff practice, and a careful analysis is critical. As a sole geared to provide service efficiency and through- practitioner, you must spend the time to research all put decisions yourself or engage advisors to assist you in this process. Solo practice will require an emergency Cosmetic Center Model—A variation on the coverage arrangement with another practitioner when conventional practice with heavy emphasis on you are out of town. You will have no immediate peer elective care in personal aesthetics and restorative consultation to explore the treatment of difficult services cases. And you will face a greater risk of losing your Super Norm Model—Emphasis on high-touch, investment. Although relatively rare, some practi- service-intensive patient experience, customer tioners just cannot earn sufficient income to remain 1478 / Endodontics profitable. This may occur as a result of choosing a work to be done, control office hours, or assume poor location, competing unsuccessfully with estab- liability stemming from the independent contractor’s lished neighboring practices, or assuming too much performance. The associate-independent contractor debt. Finally, opening your own business can come at relationship must be properly constructed to avoid a high personal cost. It will take a lot of energy and incurring significant taxes, interest charges, and personal sacrifice to get going, likely necessitating penalties. This is the province of an attorney with working at night and on weekends, infringing on experience in such transactions. personal time. HYBRID ASSOCIATE-EMPLOYEE OR ASSOCIATE- A hybrid form of employment may include any INDEPENDENT CONTRACTOR combination of the following part-time schemes: For a recent graduate with little or no prior practice (1) serving as an associate-employee or associate- experience, the benefits afforded by having a transi- independent contractor in an established endodon- tional period with an established practice can be pri- tic practice, (2) starting your own practice, and celess. Serving as an associate-employee allows the (3) serving as an independent contractor in one new practitioner to assume the reputation of the other or more general dentists offices. The latter will not member(s) of the practice, and by inference, more likely result in a stable long-term practice situation, quickly establish a good professional reputation of and should be viewed as a temporary solution, at his or her own. Other benefits include practice own- best. The value of this arrangement is that it can ership opportunities, no initial financial investment, serve as an interim step that can financially sustain immediate patient flow, peer clinical consultation, the new endodontist until he or she builds a referral shared emergency coverage, and the freedom to move base. easily to another locale if a change is desired. Risks of the associate-employee and associate- independent contractor path include the lack of total control over the practice, loss of individuality, and Winning Management Practices the legal constraint of practicing with a restrictive Forming and operating an endodontic practice is a com- covenant. A restrictive covenant is a contractual plex and nuanced undertaking. The notion that we are agreement usually between an associate and his or simply a profession and not also a business seeking heremployerthatpreventstheassociatefrompracti- financial success is to miss the opportunity to generate cing in a certain geographic area for a specified time fair compensation for your knowledge and professional period after termination of employment. These skills. Generating a healthy revenue stream is the only agreements are used by employers to protect their way to ensure that you can continue to provide the most investment in start-up costs associated with bringing advanced care available. In fact, Joe Blaes, editor of on an associate and their referral network from com- Dental Economics, states that ‘‘it is impossible for you petition. Most contracts will include a restrictive to stay in practice without a reasonable profit.’’17 How covenant, also known as a non-compete agreement. do you learn the basics of practice profitability? By study- Generally, courts have held that restrictive covenants ing other businesses to gain insights about operations are enforceable, but not in all states or under all management and best practices. conditions, so get good legal advice. What really works in the business world? In the Associate-independent contractors are independent landmark Evergreen Project, 50 leading academics, led practitioners who provide services to a dental practice by William Joyce, Professor of Strategy and Organiza- on a contractual basis. This form of practice must be tional Theory at Dartmouth College’s Tuck School of carefully structured to remain in compliance with Business, and Nitin Nohria, the Richard P. Chapman Internal Revenue Service (IRS) guidelines. Under cur- Professor of Business Administration at the Harvard rent IRS rules, the practice owner cannot control both Business School,18 looked at 40 narrowly defined the means of work and the results of the independent industries with $100 million to $6 billion in gross contractor’s efforts. No benefits, retirement plans, or revenue and determined that winning companies employment taxes are paid by the practice for the adopted four primary management practices and two associate-independent contractor. Additionally, the of four secondary management practices. Adapting this practice owner cannot furnish supplies, equipment scheme to endodontic practice, the following sections and instruments, impose safety precautions, plan summarize the study’s findings: Chapter 41 / Operations Management in Endodontic Practice / 1479

PRIMARY MANAGEMENT PRACTICES process quality. Remember, there is no reason- able way for patients to easily understand the 1. Strategy: Develop a step-wise plan to clarify your five points of the technical side of treatment. individual situation and develop a program to b. ‘‘Outside-In’’: To put this concept in perspec- achieve future goals: tive for our profession, it means understanding a. A clear value proposition: What patients and what your patients and referring doctors want referrers want most are results and process qual- and creating systems to satisfy those needs, ity. That the endodontic treatment works and from their perspective. Finding out exactly the patient can maintain their dentition and the what patients and referrers deeply value and treatment meets or exceeds the specifications of how to deliver it with passion is the holy grail the referring doctor is only the ‘‘results’’ part of of practice excellence. the equation. ‘‘Process quality’’ measures how c. Continually measure and refine: Practice metrics the patient was treated. This is the experiential can be an important indicator of your success. piece, and endodontic treatment is usually Understanding the referral process, measuring defined by patients in these terms. At the end new patient referrals, and tracking ‘‘fading refer- of the day, when patients ask the question rals’’ are examples of ways to measure the success ‘‘How was I treated?,’’ they are actually assessing of your efforts (Sidebar 1).

MEASURING CUSTOMER DEFECTIONS

In today’s competitive marketplace, success in a referral-based business like endodontics is all about building relationships. According to Frederick Reichheld,105 a business consultant and author of The Loyalty Effect,a business invests in customers, and premature customer (e.g., referring doctor) defections will ultimately result in diminished profitability. Reducing defections (also referred to as ‘‘fading referrals’’) begins with measuring the rate of defection. According to Reichheld,106 in another article in the Harvard Business Review, ‘‘customer defection is one of the most illuminating metrics in business.’’ Some defections are normal in any business and in rare cases they can even be welcomed. A percentage of referring doctors will never be loyal and can even diminish morale and increase stress if they continue to send patients. But, such welcomed defections are few and far between. In most instances, it is important to preserve and encourage continued referrals. So, what action should you take if a referral begins to fade? The best approach is to contact the individual who has stopped making referrals and find out why. Always avoid getting defensive, practice active listening, and no matter what you hear, thank them for their time and candor. You may not get these referrers back in the fold, but you may learn how to keep others from defecting in the future. Once you loose a referrer, replacing him or her will not be easy nor inexpensive. In fact, Reichheld’s survey of 100 companies in 24 industries found that longer customer retention led to increased profits. No surprise here. Many companies make the mistake of not even keeping track of customer defections because they are unaware of the cost to replace them. And many business owners find that customer defections are hard to track, especially when referrals are based on business cycles and sometimes involve only partial defections. Measuring defections can be unpleasant and remedial action is often difficult to accomplish. Even so, it is important to quantify such defections and set goals to improve those relationships. Measuring referrals is a necessary part of operating a referral-based practice. Look for practice management software that analyzes referral trends within a given time period. It should take just a few mouse clicks to get the information. Some industries report that reducing defections ‘‘by as little as five points ... can double profits,’’106 and monitoring the ‘‘fading referral’’ to measure declining business will yield valuable insights that need to be addressed immediately. The most profitable companies champion customers, recognizing that the longer a company keeps its customers, the more successful it will be. Loyal customers result in more profits, because loyal customers buy more, take less of a company’s resources and are willing to pay a price premium. Why? Because they do not want to start with new people either. Best of all, loyal referrers and patients are more likely to refer new patients. 1480 / Endodontics

Table 2 The Focusing Matrix interact with the company. So consider this action What you do best ‘‘Stop’’ ‘‘Go’’ carefully when reorganizing your staff. Keeping the vertical structure will simplify administration and What you do not do best ‘‘Stop’’ ‘‘Go with Partners will allow the staff with the best people skills to stay closest to those they serve. What your patients What your patients do not value value

The Focusing Matrix demonstrates the convergence of what you do best and SECONDARY MANAGEMENT PRACTICES what your patients and referring doctors value most. For example, take one- The Evergreen study also found a correlation between visit endodontic procedures. These are valued by your patients and referrers any two of the following four secondary attributes: and are more efficient for your office to perform. Put them in the ‘‘Go’’ category. If a procedure falls in the ‘‘Stop’’ category, consider a change. 1. Talent: The value of developing and keeping great employees cannot be underestimated; most win- ning companies reward exemplary employees to d. Keep focused: Understand your core business keep them motivated. These rewards can take and focus on the convergence of what you do many forms, among them salary, benefits, vaca- best and most profitably with what your tion, and probably most importantly a safe and patients really want. Consider a focusing inspiring working environment that drives perso- matrix showing the relationship between what nal achievement. you do best and what your patient’s value most 2. Innovation: Advanced services and technolog- (Table 2). When the two converge, you have a ies are critical to your success. Working with winner! sophisticated practice management software, advanced communications between the office 2. Execution: Deliver products and services that and co-therapists, and treatment technologies consistently meet patient expectations. Every such as microscopes and digital radiographic are business tries to set their customer’s expectations. increasingly important and expected. This research project has demonstrated that con- 3. Leadership: Trust and confidence in top leader- sistently satisfying customer expectations is far ship is one of the single most reliable predictors of more important than exceeding expectations in employee satisfaction. Leaders help employees one or more areas and falling below the grade in understand the organization’s overall business another. The customer will judge and remember strategy and how they can contribute to achiev- the worst performing parameter or interaction, ing key business objectives. Sharing information and his or her negative experience will oversha- and communicating about performance in a dow any exceptional service provided. Another small office environment by non-professional way to improve is to eliminate waste and increase HR managers/doctors can be challenging. To productivity by constantly evaluating operations improve overall performance, rewarding indivi- and making changes that improve the bottom dual employees and managers for leadership and line. creativity is a must. 3. Culture: Inspire to do your best. Every office 4. Mergers and partnerships: Partnering with employee looks to the doctor(s) and office another practice to maximize the value of diverse administrators for leadership. We must continu- talents is often overlooked in cottage industries ally refine and measure our care and motivate the and small businesses. Strategic alliances and mer- members of our office team to strive for excel- gers of individual practices to provide better cov- lence. Rewarding achievement with acknowledge- erage and economies of scale can produce bene- ment and remuneration based on performance fits. This can take the form of an alliance between will create a fulfilling workplace. several endodontic practices or the combining of 4. Structure: Simplify. Placing the best employee(s) an endodontic practice with a periodontal prac- close to the customer is another way top busi- tice, and so on. Establishing a solo group where nesses achieve outstanding results. While most two or more endodontists practice in the same businesses promote the highest achievers to the facility with shared common areas and adminis- next level in a vertically structured organization, tration but separate practice entities is another this action usually takes the best and brightest possibility to economize and protect against the and moves them away from the customers who consequences of disability or death. Chapter 41 / Operations Management in Endodontic Practice / 1481

How to Get Started 8. Detailed financial information, including your best estimates of start-up costs, revenues and Opening a new office for the practice of endodontics expenses, and your ability to make a profit. will require many months of planning. The project should begin with identifying your objectives. Do you Help in designing a business plan is available from the want to establish a boutique or niche practice or a U.S. Small Business Administration (SBA) and online more traditional practice? Will you accept insurance software guides like Business Plan Pro (Palo Alto Soft- assignment or participate with a preferred provider ware, Eugene, OR). Focus on creating a polished plan network or health maintenance organization? To suc- that can be presented to several bankers and their loan ceed, you will need to make sure your practice will be boards for consideration. The better it looks, the more appropriate to the needs and expectations of your likely you will get a favorable loan offer. If you are self- community. financing, concentrate on financial projections, Begin by creating a business plan, develop a time- because the cost of services, sales revenue, and profit line, and establish an office location that will accom- will all figure prominently in how much you will have modatetheuniquerequirementsofanendodontic to invest. Remember that starting a new professional practice. Because endodontic offices require special business will require money to market the practice. planning, the time needed for construction and instal- Very few offices today, especially in crowded urban lation will far exceed the time and expense required markets, can just hang out a shingle and expect to be for a typical non-healthcare facility. Ranking variables busy. Good planning requires making educated like location, parking, home-office travel times, ame- guesses about income and spending, based on the nities, and proximity to other medical and dental following projections: practitioners are necessary parts of the decision- making process. To get this right, you will need the 1. A break-even analysis to determine if you will services of an attorney, accountant, banker, commer- make money: cial real estate broker, architect, interior designer, a. Projected collections dental equipment supplier(s), and computer and tele- b. Fixed and variable costs (estimate) phone system engineers. c. Gross profit d. Break-even revenue 2. A start-up cost estimate to evaluate the amount of FIRST THINGS FIRST: CREATING money needed just to open the door on the first A BUSINESS PLAN day of practice. The two essential elements of a good business plan are 3. A profit-and-loss analysis to refine the month- a winning vision and a clear path to profitability. To to-month projection of profits for the first year borrow money, carefully design the plan to ‘‘sell’’ of practice. your vision to a skeptical bank loan officer. The busi- 4. A cash flow projection to ensure that even if your ness plan should include the following: business is profitable, there is enough money on hand to operate from month to month. 1. A persuasive introduction to describe your planned practice, including features and benefits, No business plan would be complete without consid- and a request for funds. eration of what business structure the practice will take. 2. A statement of the purpose. Keep in mind that this decision will affect your personal 3. A detailed description of how an endodontic liability as well as the amount of tax you and your practice works, office location overview, whether organization will pay. Whether you choose a ‘‘C’’ or you will have employees, and who will provide ‘‘S’’ corporation, a limited liability company (LLC), your equipment and supplies. limited liability partnership (LLP), general partnership, 4. An analysis of your market demographics (who or sole proprietorship, your attorney and accountant are your patients?). will need to provide advice. 5. An evaluation of your main competitors. 6. A description of your brand strategy and how you will use marketing to drive your brand to top-of- CHOOSING AN OFFICE LOCATION mind-status (see ‘‘Branding: Enabling Your Prac- Choosing where to practice is one of the most impor- tice Success’’). tant decisions a new practitioner will make. Family 7. A resume setting forth your educational and pro- considerations, personal preferences, weather, career fessional accomplishments. opportunities for your spouse, and lifestyle issues are 1482 / Endodontics among some of the considerations that should govern then using a program such as Microsoft MapPoint to your decision. Establishing a successful endodontic plot the data. Of course, there is no guarantee of practice will require a location that will provide success with any particular location, but a poor choice enough new patients to support the practice’s may lead to economic hardship. It is critical that you expenses and result in the best opportunity for you create a comprehensive plan to assure that your pro- to utilize your skills. Because the number of dentists posed site is architecturally and financially sound. in postdoctoral endodontic programs continues to Plan on specifying about 400 to 500 square feet per increase faster than any other dental specialty,19 prac- operatory in your new office.22 tice location will prove to be a key predictor of success. According to Gregory L. Morgan,23 Managing Studies by Wright,20 and Solomon and Glickman,21 Director of Sperry Van Ness – Morgan Realty Advi- using sophisticated statistical analysis, clearly establish sors, specify your geographic parameters, space the relationship between the location of general den- requirements, parking availability, modes of access, tists and the location of endodontic offices. Because and street exposure if applicable. Then engage an endodontic practice is referral-based, the proximity of experienced commercial real estate leasing profes- a referral network, followed by adequate population sional to canvas your prospective area and match your and other criteria such as socio-economic characteris- requirements with properties using real estate data- tics, are all variables that will affect the economics of bases, brokerage relationships, publications, and the your practice. Internet. Comparing the economics and qualitative The economic potential of your proposed office loca- differences between properties and market informa- tion should be appraised to determine its professional tion is where a commercial real estate leasing profes- desirability. People living in similar neighborhoods gen- sional will provide essential guidance. Hopefully, you erally exhibit similar lifestyle and spending profiles. One will have several options to review, creating a compe- of the easiest ways to learn about your clientele is to titive atmosphere where multiple landlords are com- understand their geodemographical classifications. These peting for your business. As you will learn early data, available from vendors like Business Information on, the effective rent can be based on one of several Solutions (ESRI BIS, an internationally recognized pro- formulas, and extending these costs over many years vider of information services), will allow analysis of can add up to a significant difference. Even if you are clinic site locations by creating a visual depiction of data especially focused on one of these locations, it is which is spatially referenced to the earth, also known as important to go through the exercise of requesting geographic information systems (GIS) mapping. GIS- proposals from several property owners and man- generated information will greatly improve your busi- agers. Some landlords will offer concessions in areas ness planning and allow you to base location and growth where others will not, helping you to identify the most decisions on the best available information. A new type important considerations for your business: property of classification introduced by ESRI BIS, called the location, economics, and functionality. Analyzing the ‘‘Community Tapestry’’ segmentation system, provides proposals will then help you request aggressive but an accurate, detailed description of America’s neigh- fair economic concessions from the finalists based on borhoods. U.S. residential areas are divided into 65 what other competing landlords have offered. segments based on demographic variables such as age, The next step is to decide on the number of opera- income, home value, occupation, household type, edu- tories and what supporting facilities will be required. cation,andotherconsumerbehaviorcharacteristics. Engage an architect or dental office designer to draw ESRI BIS offers market surveys that provide a detailed basic floor plans and confirm that adequate plumbing look at data within various radii around a given geo- and electrical infrastructure needs are met. Now, with graphical address. This is called a ‘‘Market Profile several lease proposals in hand, you should meet with Report’’ and is based on the updated U.S. Census, a real estate attorney for further analysis. including 5-year projections. Reports can also be According to leasing attorney Charles J. Levin,24 some ordered with specific filters, such as a plot of all general of the attributes of a successful commercial lease are and specialty practices in the zones of interest. You summarized as follows: (1) lease terms and conditions canfindthemontheWebathttp://www.esribis.com. are expressed in a complete written lease with no oral Also, ESRI BIS offers a free Web-based lookup of demo- agreements and understandings; (2) all contingencies graphic data based on ZIP codes, but ZIP codes will not are considered and resolved; (3) lease terms and condi- provide adequate specificity for making a final decision. tions are aligned with your needs; (4) the leased premises Further analysis can be performed by purchasing a suits your needs; (5) you have protected yourself from list from your state dental society in Excel format, and operating expense charges that are not customary and Chapter 41 / Operations Management in Endodontic Practice / 1483 you understand what to expect with those that are becoming more popular, and packaged with Internet passed through; (6) there are no defects like possible connectivity and television services, may prove a noise, odor, vibration, or other similar problems; (7) viable alternative to traditional service. you have warranties protecting you from issues such as After securing a telephone number and phone book zoning, water quality, mold, asbestos, Americans with listing, order the practice management software and a Disability Act (AwDA), and so on; (8) you have thor- computer workstation which will become the front desk oughly reviewed the build-out letter with your architect system. Once setup, this workstation can be located off- and contractor and included all necessary details in the site to configure your practice management software lease; (9) you have expressly excluded certain types of and allow training of new employees. Every endodontic objectionable tenants from being in the building or on practice, including a de novo practice, must have prac- your floor (e.g., music school, barbeque restaurant, and tice management software to manage appointments, social security office); (10) you have flexibility to renew, prescriptions, reports, and other communications with expand, and terminate; (11) you have option to pur- referrers, not to mention the financial aspects of treat- chase, if appropriate; (12) other tenants have no major ment and insurance. complaints; (13) you have looked into the future and considered all of the possibilities with respect to issues such as fire and casualty, condemnation, changes in CREATING A WINNING OFFICE DESIGN governmental requirements, assignment and subletting, Although building a new office from an empty shell is and the many other issues that can arise; and (14) a daunting challenge, it provides the opportunity to set you, your commercial real estate leasing professional, up the office to your specifications, within budget and attorney, and architect have all reviewed your office space constrains. A key element to insuring success is selection. Lastly, create a ticker file in your office man- the early involvement of your design team—and the agement software as a reminder of notification dates design team starts with your architect or dental design memorialized in your lease. firm. Try to choose an architect who is familiar with Levin further emphasizes the importance of you the design of medical facilities, the AwDA (Americans being engaged in all aspects of the negotiations and with Disabilities Act)25 standards, hygiene require- that you understand the significance of each and every ments, and your local building codes. By helping you provision of the lease as it is being negotiated. It is a define the building project, architects can provide mistake to hand the lease to your attorney for nego- meaningful guidance for the contractor and other con- tiation and expect that your interests are being pro- struction professionals. They can conduct site stu- tected without your involvement. There are many dies, help secure planning and zoning approvals, aspects of the lease that combine both business and perform a variety of other pre-design tasks. Evaluate legal issues that will have a profound effect upon the for handicapped patients, transportation, parking, success of the practice. The selection of an experi- and general convenience. When experienced archi- enced commercial real estate leasing professional and tects are involved at the earliest planning stage, they real estate attorney cannot be overemphasized because gain opportunities to understand your business, of the complex and nuanced nature of leasing space develop creative solutions, and propose ways to and the long-term and potentially devastating impli- reduce costs. The long-term result is a facility that cations of getting it wrong. adds to the productivity and image of the practice. Once the lease is executed, the next step is contact- Specialty architects who design just dental or health- ing the telephone company to obtain a telephone care facilities are also an excellent option, and the number and secure a listing in the local phone direc- more endodontic offices they have designed, the tory. Many telephone providers will allow you to better probability that all details will be considered. select a unique telephone number without charge or The American Institute of Architects26 provides good for a small fee. Generally, it is only necessary to secure resourcesontheirWebsiteandlistsnumerousstan- one number, which will serve as your main trunk line. dard agreement forms that can be tailored to the Additional numbers can be secured at a later time for types of services that are required. use with multi-line phone systems, to avoid paying for Steven Covey’s27 maxim ‘‘begin with the end in reserving hidden numbers prior to the opening of the mind,’’ plays a large part in creating your desired office. Today, most offices will have a choice between outcome. What do you want your office to look like? several trunk line providers and systems, such as cop- How will patients and referring doctors be best per wire or fiber optic. Use of Internet phone services served? Of course, ownership of your space in either over fiber-optic connections, such as Voice over IP, is a condominium or a stand-alone building that you 1484 / Endodontics are purchasing or building will require special con- Research in the organizational sciences has shown a siderations. direct relationship between office design and impres- After the plans are approved by the building owner, sion management. The physical environment will con- your architect and/or dental designer will be respon- vey social messages to your patients. Consider designing sible for meeting with you and any interested con- with positive visual impact, such as added accent light- tractors to explain the scope of the project and solicit ing, dry-wall soffits in key areas, upgraded ceilings, an a quote for construction. The following architectural enhanced level of detail and color balance, pleasant art- drawings and specifications will need to be avail- work and furnishings, and fabrics to further establish able: (1) site plan; (2) demolition plan, if applicable; your desired image. Keep in mind that some businesses, (3) reflected ceiling plan; (4) mechanical plan, for such as Starbucks, have left the traditional marketing to example, smoke/fire detectors and fire annunciators, their competitors, differentiating themselves through sprinkler system, heating, and cooling; (5) electrical the inviting ‘‘look’’ of their hip aesthetic that evokes a plan, for example, power, telephone, and computer satisfying experience.30 Some of the ‘‘don’ts’’ when it installation; (6) plumbing plan; (7) millwork; and comes to office design are creating physiological bar- (8) finish schedule, for example, flooring, wall cover- riers, that is, sliding glass enclosures between patients ings, and paint. The contactor will generally be and the patient coordinator, showcasing your hobbies; responsible for getting approval from local building unclean, inexpensive, or misarranged furniture; and off- officials to begin construction. putting signs in the reception area [a big no-no, with the Designing the office for new and even future tech- exception of a Health Insurance Portability and nologies will require some coordination between the Accountability Act (HIPAA) notice, if applicable]. Signs various planners of your space. The wires and cables that tell patients about office policies, in general, are must be installed and integrated for the practice man- unwelcome reminders of what your office personnel agement system, digital radiography, entertainment, should have advised either verbally, or in the office’s power, fire and smoke annunciators, security systems, literature or Web site in the first place. and climatic systems.

Branding: Enabling Your Practice Success Design Aesthetics Dental practice begins as a journey after dental school 28 According to Schmitt and Simonson, ‘‘aesthetics is with little or no training in the business aspects of one of the major satisfiers in consumers’ experiential practice. Unfortunately, talent and education alone worlds.’’ They state that intangibles like experiences are not enough to ensure success in our increasingly become key selling points when services are perceived competitive healthcare marketplace. Getting and as the same across an industry. keeping patients in our endodontic practices will How can Starbucks charge over $4 for a cup of undoubtedly become more challenging, especially in coffee? It is because they provide experiences that cus- mature urban settings. In order to develop long-term, tomers can see, hear, touch, and feel—experiences that directed growth, we must learn to manage our prac- add value and allow for premium pricing. In the same tice building efforts through trial and error, intuition, way, your practice will become identified with certain reading, continuing education, and use of manage- traits that create a practice image, requiring ‘‘a careful ment consultantancies. mapping of a strategic vision to create sensory stimuli Before we address the ins and outs of practice opera- and communications that evoke that vision – that tions, we should first explore the case for concern, the instantiate the identity’’.29 It is important to establish meaning of branding, and ultimately how to build a a style that is consistent throughout everything your brand-driven culture within your organization. At the practice does, from your Web site, to your brochure, to end of the day, building you brand in a way that the design of the office interior. Bloch,30 in his research energizes all referrers, patients, vendors, and employees to conceptualize consumer reactions to a product’s must become the mantra of your operational strategy. design, says there are three basic consumer responses, namely, ‘‘cognitive, affective and behavioral’’. He goes on to state that product form—or in this case office THE CASE FOR INCREASED CONCERN aesthetics—influences behavioral responses thro- In the United States, we are facing many new challenges ugh cognitive and affective responses and are based in private endodontic practice. Endodontics is one of on individual tastes and preferences. the smaller clinical specialties in dentistry, with about Chapter 41 / Operations Management in Endodontic Practice / 1485

4,000 practicing clinicians in 2007, and a population to business strategy consultant, in the past, a brand used endodontist ratio of about 75,000 individuals per endo- to say, ‘‘If you buy this product or buy from my dontist. However, with our population projected at 340 company, you can rely on me because of the attributes million in 2035, and with endodontists graduating and attached to the brand.’’ He goes on to state that we are leaving practice at approximately the same rate as today, seeing ‘‘a new kind of branding emerge, a much more we are projected to have approximately 6,580 active customer-centric branding, where the promise is, ‘I clinicians or a population to endodontist ratio of know you as an individual customer better than any- 54,270 individuals per endodontist. At current gradua- one else, and you can trust me to assemble the right tion rates, the number of dentists completing endodon- products or services to meet your individual needs.’’’ tic residency programs has been increasing faster than Brands are imbedded in our minds and used in our the number of general practitioners, and as a conse- daily lives, like ‘‘FedEx that photo to San Francisco.’’ quence, the practitioner to endodontist ratio has also Your brand is your personality; brands are the reason been declining. The vast majority of endodontists prac- that companies exist, and they are based on multiple tice in the Northeast and West Coast areas, and if experiences over time. These experiences, from the misdistribution trends continue, the number of over- patient intake process through treatment and post- served areas will continue to increase with resultant treatment interactions, need to be delivered with con- case-load challenges. Other factors, such as the higher sistency and be perceived as unequaled relative to the relative failure rates in restorative materials like resins, competition. In short, your patient’s and referrer’s general dentist busyness, and increased productivity experiences need to result in deep, trust-based rela- among all practitioners will continue to be some of tionships which generate loyalty. Your brand should the issues affecting the profession.31 Areportbythe reflect a high level of education, proficiency, and con- DTA concluded that up to 40% of all practices are not fidence that you are offering the best care. reaching their full production. By the year 2010, it has While brands speak to the mind, brand identity or been postulated that less than 40% of all dental care will brandmark is the sensory expression of a brand. You be provided by non-owner doctors rather that more can touch it, hear it, feel it, and it increases the custo- traditional practice models.32 The competitive land- mer’s consciousness and builds loyalty. Your brand- scape will continue to change, according to Eric Solo- mark can include a name, design, or symbol that mon,33 Professor of Public Health Sciences at the Baylor visually represents the value of your practice beyond College of Dentistry, in his Dental Economics article its functional purpose. The velocity of life in the future ‘‘The Future of Dentistry.’’ He predicts that the number will inevitably demand that brands leverage the power of specialists in dentistry will increase from the current of symbols. Whether it is a photograph, mark, graphic, level of 20% to 27% by the year 2020,’’ leading to an or typographical image, which can be as simple as the increasingly competitive marketplace for the new spe- practice name written in an artful font, symbols can cialist. The days of opening a new office in a major trigger recall and stimulate emotion. A brand identity metropolitan area and instantly generating a sustainable helps to manage perceptions of your practice and financial model are becoming increasingly rare. differentiates it from other practices. Increasing competition, demographic shifts, market Offices must deliver their services to create value saturation, bunching of endodontic practices in that relies on understanding results and process qual- already crowded urban centers, insurance company ity from the referrer’s and patient’s perspective. When control, and an insidious lack of customer loyalty will it comes to understanding your clients, according to always challenge endodontic practices in the most Marty Neumeier,35 a branding consultant, ‘‘Brand is desirable markets. Central to meeting these challenges not what you say it is. It is what they say it is.’’ is creating a brand identity that consistently conveys Although branding is a simple concept, it is not that our special skills to referring doctors and patients. easy to accomplish. It takes a long-term commitment What follows is a summary of branding basics, with and hard work. an emphasis on the connection between best business In the early 1990s, brands were a series of market- practices and the dental profession. ing tactics like the advertising icons made famous by Nike, Alka Seltzer, and even KFC. Brands now have strategic importance, brands result in deep, trust- UNDERSTANDING YOUR BRAND based relationships which in turn garners customer’s What is a brand? A brand is simply a promise—the loyalty. Products and services need to be delivered expectations that exist in each customer’s mind about with consistantly high level of quality and value, per- a product or service. According to John Hagel,34 a ceived to be unparalleled relative to the competition. 1486 / Endodontics

Adopting this brand-driven approach, ‘‘where making the brand the central focus of the organization clari- Customer Satisfaction Index fies what is ‘on-brand and what is off-brand’’’.36 Then the entire organization needs to adopt this brand- 50% driven approach to guide critical business decisions 45% as well as determine appropriate staff behaviors. 40% Building a brand-based culture is simply not a quick 35% fix program. It requires a solid dedication to the 30% organization’s brand vision and an understanding 25% that branding cannot be overemphasized an overall 20% strategy. 15% As we learned in the beginning of this section, a 10% 5% brand is a promise that defines a patients’ value pro- 0% position that both their treatment and their experi- 12345 ence will be as expected or better than expected. ‘‘It completely neutral completely has meaning, prestige, and presence, and it helps dissatisfied satisfied confirm what is expected’’.37 The treatment per- formed must be unrivaled and the patient and referrer Figure 1 Customer Satisfaction Index. In this typical customer satisfac- experience must be unequalled. According to Pro- tion index, completely satisfied customers, rated 5, were six times more 38 likely to repurchase a product or service over the next 18 months than phets 2002 Best Practices Study, there are three 40 just merely satisfied customers, rated 4. main goals of any branding strategy: (1) increasing customer loyalty, (2) differentiating your organization from the competition, and (3) establishing market ability.’’ If we look at the lifetime value (LTV) of a leadership. Let us look at each of these goals and top-tier referring doctor whose career spans 35 how they affect practice success. years, revenue generated will easily exceed $1.5 million. While calculating LTV is complex 1. Increasing customer loyalty: A classic study by because of varying costs to acquire and maintain Xerox in the 1990s (Figure 1) looked at satisfac- each customer, there is no doubt that looking at tion and found that highly satisfied customers the ‘‘customer back’’ will allow formulation of were six times more likely to repurchase a Xerox strategies for each customer segment. Customer product than a merely satisfied customer.39 This loyalty rules! means that every highly satisfied patient will 2. Differentiating your organization from the com- demonstrate repeat behavior and require much petition: If a customer cannot tell the difference less effort on your part to maintain their loyalty between your service and another, they will buy than patients who are just along for the ride. Even on price. A practice needs to invest in the things more important, a patient who repeats their that highlight a unique benefit to the customer behavior is much more likely to continue repeat- and deliver it with skill and finesse, like a con- ing it, becoming more profitable as time goes on. cierge at a fine hotel. Identify and build on the For example, it takes the average credit card qualities or characteristics which make your prac- company 3 to 4 years of marketing effort to tice distinctive.43 Every customer, whether pur- attract a new customer, or 7 to 10 times the cost chasing a car, hospital services, or endodontic of merely maintaining an existing customer. An care usually has a choice. Your job is to wind up increase in customer loyalty of just 2% will equal in the referrers’ final consideration set and then the equivalent of a 10% cost reduction program, be chosen because of your unique capabilities. It and an increase of 5% in loyal customers can can range from a high-tech approach using a Web deliver 95% greater profitability over the lifetime based patient intake process to digital radiogra- of that customer.40 Even more striking is that phy and microscopic imaging to non-surgical 50% of customers will try a new product or revision therapy to diagnosing a difficult case. service from a preferred brand because of the Remember that technology implementation costs implied endorsement, credibility, and trust.41 money, so do not market your practice as the best According to Robinette et al.42 of Hallmark in town and then price it low, because you are Cards, Inc, ‘‘increased customer loyalty is the sending a mixed message and wasting some of single most important driver of long-term profit- your marketing dollars. Learn what characteristics Chapter 41 / Operations Management in Endodontic Practice / 1487

make you office distinctive. If you are going to be sionals or community organizations is endless. Here a brand, you must be inexorably focused on what are a few examples: (1) teaching at a dental school, (2) you do that adds value. getting involved in philanthropic and civic organiza- 3. Establishing market leadership: First and foremost, tions, (3) providing continuing education, (4) spon- communicate that you are a specialist. Make sure soring a blood drive with the American Red Cross that patients understand that you have undergone (Sidebar 2), and (5) partnering with another dental extensive post-graduate training. Use verbal and office to benefit a community program like a soup written communication to focus attention on con- kitchen, food bank, and so on. tinually improving outcomes with the latest science by using evidence-based treatment that leads to a painless procedure with the highest level USING TECHNOLOGY TO of success possible. Reveal the hidden by using OPERATIONALIZE YOUR BRAND models, drawings, and microscopic/radiographic imaging to increase the patient’s understanding Although all endodontic practices provide basic speci- of the procedure. For example, drawing a scaled alty services to patients and referring doctors, it is the diagram for each patient at the end of their visit value-added services that can help differentiate your will demonstrate your special skills. Be sure to let practice from competing practices. Research con- patients know that treatment you perform through tinues to link business success and professional the microscope is reflected through a mirror, so achievement with developing long-term appeal and that every hand movement is reversed. Use tech- credibility. And adopting proven technologies is one nology to create a value proposition for all stake- of the most visible and reliable ways to create a posi- holders—defined by modern management science tive impression and to continually engage patients, as everyone with an interest in what the organiza- referrers, and staff, to say nothing of the clinical tion does, such as clients, employees, and vendors. advantages. Demonstrate your proficiency both singly and as a Patients expect a high-tech approach to treatment. team, reaffirm the patient’s choice of endodontic In fact, the National Health Information Infrastruc- treatment over extraction by addressing the bene- ture (NHII) is establishing a national electronic infor- fits of decreasing dental disease to improve overall mation network for heath care. The NHII proposes to implement a computer-based patient record for most health, show sensitivity to patient’s mental and 45 physical comfort, provide impeccable service, and Americans by 2014. So how will your practice mea- offer superb facilities.44 sure up? With the expanding use of technology in every aspect of life, patients expect their healthcare One of the best ways to establish market leadership is encounters to include the newest technologies. Use of to use state-of-the-art technology to create value in the Internet to improve patient intake, receiving elec- the referrer’s and patient’s mind that they can see and tronic receipt of patient pre-treatment radiographs understand. Every patient treatment communication and information, digital radiography, computerized should reflect your technological competence. Digital charting, microscopes with imaging capability, instant radiographs and photographic images along with communication of your treatment reports by email, cogent narratives of treatment should reflect your online pharmacology information at the chairside, commitment to the latest technology and help oper- and music and entertainment options are all ways that ationalize your brand. Performing a state-of-the-art your office can project a technologically advanced procedure and then communicating the results by practice image. The list goes on and on, but the sending a film-based image and a few handwritten importance of differentiating your practice cannot be notes misses the opportunity to maximize your image overestimated, and one of the best ways is with useful as technologically sophisticated. This leads us to the and visible technology. next section about how to develop brand-building ‘‘A brand strategy is a statement of the brand’s programs that are the most cost efficient, effective, sustainable competitive advantage, usually consisting and credible. of a demographic and psychographic description of There are many ways to help define a brand. the intended customers and the benefits they get from Volunteerism and community outreach programs the brand.’’.46 A brand-driven approach will create are valuable ways to ‘‘give back’’ and also help your customer loyalty that will ultimately translate into a stakeholders understand your brand philosophy. The competitive advantage and increased profitability. list of opportunities to partner with other profes- Modern management science defines everyone with 1488 / Endodontics

OFFICE DESIGN

Appealing to consumer needs has defined marketing for the past one hundred years. According to Abraham Maslow107 in his book Motivation and Personality, once basic consumer needs like survival and safety are satisfied, higher order needs like experiential and aesthetic needs become increasingly important. A simplified version of his thesis depicts a pyramid with experiential and aesthetic needs at the top, which leads to the false conclusion that aesthetics is a luxury that humans care about only when they are wealthy. To the contrary, Virginia Postrel,108 in her book The Substance of Style, states that ‘‘aesthetics is not a luxury, but a universal human desire.’’ She contends that humans do not wait for all of their lower order needs to be satisfied before wanting aesthetic environments and products. She goes on to say that ‘‘there is no pyramid of needs, where each layer depends on what we already have,’’ but rather we make important decisions every day based on our sensory experiences. These experiences are based on the precept that appearance counts and that aesthetic value is real and gaining even more importance in the twenty-first century. According to Postrel, we have entered the ‘‘Age of Aesthetics’’ when beauty and style are found everywhere in market economies. Simply put, increasingly sophisticated consumers demand ‘‘an enticing, stimulating, diverse and beautiful world.’’109 To this end, a coordinated and appropriate office aesthetic is important, and color, texture, sounds, lighting, and artwork will all lead to an identity that will satisfy patients experiential and aesthetic needs. Creating positive attitudes and beliefs about your organization and its services will be influenced by how you deal with your brand identity. The overall impression of your practice will often depend on the management of the themes inherent in individual identity elements that must be coordinated and designed to convey your brand characteristics.110 Themes are an expression of your organization’s core values or mission and are typically created by graphic designers, interior designers, architects, and marketing experts. The level of finishes you choose should follow a consistent design theme and may include (1) lighting accent fixtures; (2) dry-wall soffits and upgraded ceilings; (3) color balanced walls and carpets; (4) coordinated artwork and furnishings; and (5) harmonized vinyl, fabrics, and custom finishes. Items that may cause negative visual impact include (1) showcasing your outside interests; (2) inexpensive furnishings and artwork; (3) unclean and misarranged furniture; and (4) signage that gives information that could be reasonably explained by the office staff. I hate reception area signs! When designing or renovating your office, strongly consider what the patient sees and design with them in mind. An office design that resonates with patients is an important factor in establishing a patient’s trust and helps them measure the quality of your treatment. Design themes should be repeated and coordinated to express a close association that increases recall and puts your practice in ‘‘top-of-mind status.’’

an interest in what the organization does, such as tion of employees and improves morale, aligning each clients, employees, and vendors are called stake- team member with your brand promise. All employ- holders. And each interaction with a stakeholder must ees need to think, speak, and behave in ways that be understood and prioritized along the entire treat- create the kind of patient and referring doctor experi- ment cycle. ence that has lasting impact. Assimilating your brand How important are employees to the branding pro- among the employees of your organization will ensure cess? The success of any branding strategy depends on that all employees understand and embrace your engaging employees around your brand in a way that brand and can translate this into actionable behavior. encourages ownership of the brand. We have all This way employees become brand advocates that experienced the exceptional employee who under- understand how his or her impact can affect satisfac- stands the brand’s unique character and communi- tion and ultimately loyalty. cates it to all of the practice’s patients, for example, patients, referring doctors, and fellow staff members. Employees who are engaged around the brand con- EMPLOYEE MOTIVATION AND MORALE firm that the patient, referrer, and the brand are the Every business relies on its organizational values to things to focus on. It facilitates recruiting and reten- deliver on its brand promise. Employee attitudes and Chapter 41 / Operations Management in Endodontic Practice / 1489 retention rely on a cohesive and upbeat culture. In BECOMING A LEARNING ORGANIZATION order to develop brand advocates among all of your When you go to a barber shop or a salon to get a haircut, employees, your practice must first generate excite- you tell the barber or hair stylist exactly how you want ment about what it does. If each employee under- your hair done. After a few visits to the same person, he stands the benefits of modern endodontic treatment, or she will probably know just how to shampoo, cut and, it will reinforce their choice of employment. It can blow-dry your hair. You have invested time and energy foster a sense of belonging to a profession they are to tell them how you want it, and they will have likewise passionately proud of. Employees need a leader who invested in learning your preferences. In fact, the more clearly understands the mission of the practice and youtellthemaboutwhatyouwant,themorelikelyyou can communicate his or her vision to each employee, will revisit the same hair stylist, because, after all, you patient, and referring doctor. have invested in them to create a mutual relationship. Brand-driven behaviors are enhanced by establishing We have all experienced this kind of service and will tend a strong brand-based culture that is constantly fed and to frequent the same establishment time and again nurtured. It is crucial that your brand commitment is becausetheyhaveestablishedalearningrelationship.If evident from the top down. If employees think that the you were to switch to another barber or stylist, you would practice leadership believes brand building is a priority, have to make that investment all over again. According they will embrace it with the same passion. Each endo- to Pine et al.49 in an article in the Harvard Business dontist in the practice must communicate their endor- Review,customers‘‘wantexactlywhattheywant–when, sement of the practices’ brand vision so that every whereandhowtheywantit.’’Andacompanythat employee experiences appropriate modeling at every aspirestogivecustomersexactlywhattheywantmust level of stake holder interaction. Without leadership establish a learning relationship that ensures that all support and willingness to lead by example, the old stakeholders collaborate. Developing learning relation- Russian proverb ‘‘the fish always stinks from the head ships with referrers is critically important. The more downwards,’’ will resonate loudly. you know about how they want it (new patients sent Successful brand strategies require a clearly articu- right over for consultation, one-visit treatment whenever lated vision of what your organization’s brand stands possible, etc.), the greater chance that this referrer will for and how to link it to your overall business strat- continue to use your services. If you think about the cost egy. For example, if employees are to bring the brand of replacing one referrer with another, consider their to life, a strategic foundation must be established. One lifetimevalue(LTV).LTVisthesumofthestreamof important first step is to establish well-defined roles profits attributable to this referrer. Take the average value for your most important asset—your employees. The of referrals in a year and multiply it by the projected notion that your patient coordinator can just answer number of years you intend to practice and you will see the phone, assign appointment times, and have cus- how important each referrer is to the bottom line. tomers fill out forms in the reception area will not New paradigms of patient care are emerging as the lead to a patient-centered practice model that will relationship between oral disease and systemic heath generate a loyal following. There needs to be a con- become clearer. Developing a learning relationship with versation between the patient, referring doctor’s physicians is an emerging area that can enhance your office, and your staff that is welcoming, informative, professional image with non-dental sources of referral. and nurturing. It is clear from the work of Silversen In order to continually differentiate your practice, con- and the Werthlen Group that the better prepared a sider practice-building strategies that incorporate the patient is before treatment, the more positive their 47 latest research in endodontics or health care in general. treatment experience will be. Of course, our treat- Liaising with other healthcare providers is a good way to ment must conform to the best available practices of promote improved health and communicate your brand the day, but also must provide the key satisfiers of the 48 identity. Study clubs, continuing education opportu- patient experience. In Bernick’s Harvard Business nities, one-on-one meetings, Web sites, and publications Review article about corporate culture, Alberto-Culver can create valuable brand advocates. was able to boost sales 50% by creating a more customer-centered approach. It embraced a manage- ment culture that listened to its employees, celebrating BRAND ASSIMILATION: PUTTING events like birthdays and anniversaries, and creating THE PROGRAM INTO ACTION passionate advocates of their brand. Without brand The most successful organizations divide brand assimila- advocates, your practice will just muddle along, redu- tion into three phases: strategic development, foundation cing the likelihood of reaching your desired future. building, and implementation.First,developastrategic 1490 / Endodontics plan that defines the scope and objectives of your pro- satisfied customers.50 What is the take-home from gram so that the right people and systems are identified this study? Simply put, the key to business success is to carry out your program. The second phase is founda- to create as many loyal referrers and patients as pos- tion building, the process of aligning all employees sible. Then to market your practice in a way that not around the central theme of your branding initiative only maintains your most loyal referrers and patients, through office workshops and reading. This is where each but attempts to increase their ranks by ‘‘marketing employee segment (e.g., chairside assistants and patient below the gold.’’ In other words, spend the bulk of coordinators) learns about your brand initiatives and your energy and precious marketing dollars taking a their role in communicating your message. The idea here merely satisfied referrer and elevate them to the extre- is to guide behaviors that foster participation and allow mely satisfied category. all employees to understand the benefits of your key What are the benefits of loyalty? Patients will objectives. Implementation, the final phase, is where a recommend your office to others. Hearing about rangeoftacticsareemployedtocreatekeymaterialsand how great your brand is from someone else will clearly talk about successes that will change employee behavior be much more effective than self-promotion. Loyal throughout the practice. As always, it is important to patients are more accepting of new services, will say monitor the responses to your program and make ‘‘no’’ to substitutes, and will pay a premium price for changes as necessary. you to treat them. According to Passikoff,51 over 50% Establishing a brand assimilation program will lead of customers would pay a premium of 20 to 25% to a number of changes, but at what cost? How do before they would switch to another brand. The ben- you measure success? The first hurdle is to make sure efits of developing loyal patients cannot be overem- that your employees understand your brand initiative. phasized. It takes 7 to 10 times the cost to gain a new They have to be invested in developing significant customer than to keep an existing customer. So do relationships with your patients. When your employ- whatever it takes to retain your current patients. ees assimilate your brand, you can begin to imple- Remember that a service needs to do what is expected, ment an action plan that markets your brand. One as expected, for as long as expected throughout the effective program can be an orientation luncheon for customer experience. a referring office. Have all of the referrer’s office staff Build on what differentiates you from the competi- join your staff for a catered luncheon, conduct a brief tion. If a patient cannot tell the difference between office tour, and present a short program to let them one service and another, they will buy on price. A know how you welcome new patients and how good practice needs to invest in the things that highlight a communication between your offices can build unique benefit to the patient and referrer and deliver patient confidence. The practice should strive to high- it with skill and finesse, like a concierge does in a fine light the ways that both practices can work together. hotel. After all, patients and referrers really want just Changes in organizational culture do not happen two things: results and process quality. The results part quickly. It takes a considerable amount of leadership of the equation applies to a great diagnosis or root and vision to promote meaningful changes to employee canal procedure, where the patient feels that he or she behavior.Butthepayoffwillbeastrongbrandthatwill received caring service and state-of-the-art care and resonate with patients and referrers and help excite the referrer feels confident to complete their restora- employees. This will ultimately result in increased loyalty. tion. Process quality is how the referrer and patient While the detailed application of these disciplines is were treated. Was the patient seen on a timely basis? beyond the scope of this chapter, it is instructive to Was the referral handled seamlessly? Was their treat- look at the relationship between providing services and ment compassionate, respectful, and safe? Did the recognizing the link between loyalty and profitability. procedure make the referring clinician seem like The service-profit chain provides just such a model for everyone was on the same team? operating in the medical environment. This is where Today’s consumers are increasingly brand-centric, leadership develops a dedicated team that provides and developing a brand identity is an important superb service to patients that go on to develop loyalty element in differentiating your services.52 The pro- to your organization. blem is how to get started so that you can deliver When customers are highly loyal, there are minimal your brand across every touchpoint and every stake- considerations of other brands. In the Xerox study holder. Begin by formulating a brand strategy that quoted earlier, a survey of 430,000 customers revealed creates visibility and recognition, unaided recall, top- that highly satisfied customers were six times more of-mind status, deep customer relationships, and likely to repurchase a Xerox product than merely build differentiation. Chapter 41 / Operations Management in Endodontic Practice / 1491

Does this seem impossible? Collins and Porras53 ask nuum that begins with the introduction of endodon- the question of how to use words that are not mean- tic therapy and only ends when the patient no longer ingless. All McDonald’s corporate strategies are still needs your services. Dividing these interactions into guided by Ray Crock, McDonald’s late founder’s three brand life-cycle stages, pre-treatment, treatment, acronym, QSVC (Quality, Service, Cleanliness, and and post-treatment procedures, each interaction can Value). Social psychology research indicates that when be choreographed to create a value chain that consis- people publicly espouse a particular point of view, tently fulfills the patient’s clinical and experiential they become more likely to behave in a manner con- needs. These steps are really brand touchpoints, or sistent with that point of view, even if they did not the different ways your services interact with patients, previously hold that belief. ‘‘Passion is a pretty fool referrers, and fellow staff members. The members of proof test of whether a value is a core value,’’ says your staff have to serve as brand ambassadors, and Mike Moser,54 an advertising and marketing expert. each interaction with patients and referring doctors ‘‘It will help you include your heart in the decision- must be consistent to ensure the best experience. making process instead of just your head. Passion is In order to be truly successful, every functional area what creates an emotional connection that transcends in your organization must be responsible for bringing ads, public relations, brochures, or any other crafted the brand promise to life. There must be total align- messages that a company puts out.’’ ment between your organization and your brand The brand–customer relationship remains one of strategy, so that you control the critical interactions the most underleveraged and yet potentially powerful your patients and referrers, or stakeholders, have with ways to drive sustainable, profitable, and long-term your brand. What are all the touchpoints that exist value back to your practice. First, determine your between your brand and a current or potential stake- practice’s core values. ‘‘Visionary companies tend to holder? How can you create a brand-driven organiza- have only a few core values, usually 3 to 6. . .only a few tion? Outlined below are 10 brand touchpoints com- values can be truly core values so fundamental and monly found in endodontic practices. Please note that deeply held’’ that they will rarely change.55 only 5 of the 10 involve the practitioner, and only one Every office has a personality, so maximizing the of these involves the practitioner alone. The impor- benefits of your practice by showing genuine warmth tance of selecting an outstanding staff and taking and sincere concern for the patient’s comfort are part control of all patient and referring doctor touchpoints of a thoughtful brand approach. Simple things like cannot be overemphasized. offering a warm, moist towel after treatment, provid- 1. Patient is informed that they need endodontic ing appropriate music or video entertainment, and treatment: The process begins when the patient always using the most current technology are critical is advised that he or she needs an endodontic to establishing your brand personality.56 Always make consultation. Providing each referrer with a kit sure your brand personality is appropriate for your that contains your office brochure, referral forms, audience. Is it predominately male or female, blue appointment cards, business reply envelopes, and collar, white collar, or service workers? Demographic Web site information will help introduce patients studies have shown that endodontic patients are 60% to your practice. According to Jack Silversin,58 in female, average 48 years old, with 69% older than 40 his American Association of Endodontists-funded years old.57 study to learn about the endodontist–patient rela- tionship, the more your patients know about their BRAND TOUCHPOINT OVERVIEW treatment in advance, the better their treatment experience will be. Like most world-class businesses, the best endodontic 2. Patient calls for their first appointment: When a practices operate with a clear vision to ensure peak new patient calls for an appointment, complete a performance. Just like an Olympic hurdler who men- written telephone intake form or software-based tally previews his or her performance before an event, pre-registration form, and set up an initial appoint- from leaving the starting block to breaking the finish ment. The telephone intake form should be line, each element in the patient’s visit must be care- designed with a sequenced set of questions in order fully planned to ensure that patients feel they are in to get efficiently critical information and document right place. Every staff member contributes to a suc- that all pre-treatment instructions were given. cessful visit by interacting with patients in a profes- sional and caring way. It is useful here to visualize the Telephones are an essential part of the new patient patient and referring doctor experience as a conti- experience, so make sure that proper telephone etiquette 1492 / Endodontics is practiced at all times. According to Albert Mehra- 3. Patient arrives for first visit: When patients arrive bian,59 a pioneer in communications research, there are for their initial visit, be prepared and give them a three elements to any face-to-face communication: warm and sincere welcome. Patients can complete words, tone of voice, and body language. When it comes their registration on a reception area computer to feelings and attitudes, approximately 7% of meaning is kiosk connected to the practice’s network or the in the words that are spoken, 38% of meaning is para- Internet, or fill out paper-based forms and view linguistic (the way that the words are said, like smiling on educational materials while in the reception area. the phone), and 55% of meaning is in facial expression. This is the time for scanning any film-based The telephone creates an immediate communication gap radiographs or appending digitally transmitted because facial expression is not apparent, so the words images into your radiographic database, if applic- and paralinguistic attributes take on added importance. able. Some endodontic software can allow front New patients should be queried about their status, office personnel to indicate the patient’s status because patients in pain and/or swelling are interested from their arrival at the office and transitioning in immediate treatment and will generally accept sche- through treatment and finally discharge. Besides duling at the convenience of the office. These patients depicting the status of each patient in the office, will ideally need to be appointed the same day they call. recording the chair time for each type of proce- Patients who have no discomfort or mild discomfort dure will allow create metrics that can be used to will generally be interested in convenience. measure profitability. There are several methods available to provide 4. Patient is escorted to operatory: Escorting patients to pre-treatment information. Invite new patients to the operatory is an opportunity to connect staff and view your office Web site, where they can complete patient. Employee name badges and a policy of each a secure patient registration and health history form. staff member introducing himself or herself to the Web sites are necessary, if not a necessity, in today’s patient by name should be practiced at all times. healthcare environment. According to Harris Inter- Also, chance encounters in the office where a patient active, in a poll of 1,015 US adults conducted in is within five feet should prompt a ‘‘hello’’ greeting. 2005, 72% search the Internet for health-related information.60 Almost 58% report looking for infor- When the patient is seated in the dental chair, the mation often search the Internet for health topics patient’s individual record should appear on the chair- andonly14%saythattheyhardlyeversearchhealth side computer screen in the operatory, maintaining topics. Even more remarkable, 85% of those who HIPAA compliance, and assuring the patient that your have ever searched the Internet for health-related efforts will be focused on them. Once seated, the assis- information did so in the last month of the study, tant should confirm that the patient has followed all and now averages seven searches each month per pre-treatment instructions, including their antibiotic patient. What does this mean to the endodontic pre-medication regimen if any, other pre-treatment practitioner? Today, patients expect to meet their medications, and have eaten breakfast or lunch to prospective practitioner on the Internet. Mailing, ensure a normal blood glucose level, whichever is faxing, or emailing a ‘‘welcome kit’’ to patients with appropriate. Of course, staff should confirm that all a welcome letter, brochure, procedure explanation, prescribed medications have been taken on schedule, doctor biography, financial policy, registration, and if sedation is contemplated, an escort is present to health history form, and map are also valuable ways accompany the patient after treatment completion. This to streamline new patient intake. Creating a Web site to isthetimeforyourstafftotellthepatientwhatcomes provide patient education opportunities, contact infor- next and set their expectations for their visit. Assuring mation, and referral materials will further enhance pre- that their comfort is of utmost importance, offering a treatment preparation and provide the most convenient blanketorpillow,describingwhattreatmentwillbe and cost-effective solution. While society is becoming performed, length of the visit, and so on are all impor- more accustomed to automation and the advantages it tant. Acknowledge and reassure the patient that his or her provides, ‘‘dentists must be careful not to allow tech- concerns will be addressed. This is also the time to project nology to interfere with the relationship between patient a safe practice image. Sanitize your hands in front of the and doctor and the patient and staff.’’61 patient or let them know you are leaving the operatory to If the office must meet the requirements of HIPAA, wash. Wear proper clothing and limit masks, gloves, and all online transactions, as well as the office network, other protective gear to the clinical areas of the office. It is must be secure. If the office uses a wireless network, incumbent on the endodontic practitioner to convey a appropriate security measures are required.62 senseofsafetythroughouteachvisit.63 Chapter 41 / Operations Management in Endodontic Practice / 1493

This is the time for the dental auxiliary to record sey require dentists to provide informed consent the chief complaint, history of present illness, medical even for non-invasive procedures. Also, a patient’s history and review all current medications. Once the refusal of recommended treatment should be general area of interest is determined, the auxiliary documented in writing to ensure that the patient should expose dental radiographs, record photo- comprehends the possible consequences of refus- graphic images, take vital signs, answer questions, ing treatment. After the discussion and informed and, most importantly, comfort the patient. Each staff consent processes are completed, any additional member should be dressed and groomed appropri- pre-operative issues should addressed. Any patient ately, scripted for this interaction, with the best who has not eaten a timely meal and will receive answers to commonly asked questions to promote local anesthetic should receive an appropriate consistency and accuracy. Of course, all medications nutrient supplement to avoid syncope from low should be recorded in the patient’s database so new blood glucose levels. EnsureÒ and GlucernaÒ are prescriptions can be automatically checked for lactose-free drinks designed for occasional meal advised interactions and cautions. replacement and intended for non-diabetic and diabetic patients, respectively. If non-steroidal 5. Doctor consults with patient: After introduction anti-inflammatory drugs or antibiotics are indi- by the dental assistant, you should establish eye cated, they can be dispensed at this time. contact, make sure the patient is comfortable, lis- 6. Doctor treats patient: Every effort should be made ten attentively without interrupting, and according to include the patient in the treatment process. to MaryJo Ludwig64 Clinical Faculty, Depart- Confirm that all of the patient’s questions are ment of Family Medicine at the University of answered. Then treatment can be initiated along Washington Hospital, ‘‘acknowledge and legiti- with documentation of the visit. If digital schedul- mize feelings, explain and reassure during exam- ing is available, patients can be reappointed while inations, and ask explicitly if there are other areas still in the operatory and their insurance informa- of concern.’’ First impressions are important, and tion can be sent to the office financial coordinator your first contact with the patient is no exception. via the network or directly to the insurance com- Psychiatrists Leonard and Natalie Zunin,65 stated pany, if the office LAN integrates with the Internet. in their book ‘‘Contact: The First Four Minutes,’’ 7. Doctor discharges patient: Once the treatment is that, on average, there is only a short moment in completed, the final 4 minutes should focus on time, a 4-minute window, ‘‘to grab someone’s the patient and their post-operative instructions. attention and establish credibility and rapport.’’ Communicate that you are a specialist by drawing These first impressions demonstrate our compas- a scaled diagram for each patient at the end of sion, care, intelligence, attention to detail, and their visit that explains the intricacy of your pro- pride. Be sure to limit the time you spend with cedures. Use technology to create a value propo- the computer at the expense of eye contact and sition for all patients. In the end, be sure to take personal interaction with the patient. Once the every opportunity to complement the patient on patient’s dental needs and intake data are their cooperative attitude. Medications can now reviewed, the initial oral exam is completed, a be dispensed, as necessary, and prescriptions discussion and informed consent can take place. selected and sent to the printer. According to Peter Sfikas,66 chief legal counsel of 8. Patient is escorted to front desk: Patients are then the ADA, the ADA’s Code of Professional Conduct escorted to the office departure station and rein- requires dentists to ‘‘inform patients of proposed troduced by their escorting assistant to the patient treatment and any reasonable alternatives in a coordinator. Sit-down departure stations at the manner that allows the patient to become involved front desk will serve to increase patient comfort in the treatment decision.’’ Every dentist should and to better accommodate disabled patients. In understand the requirements of their state practice some endodontic offices, advanced practice man- laws with regard to informed consent. In this agement software will allow the clinician or assist- regard, states differ greatly. In Pennsylvania, for ing staff to forward all pertinent billing state- example, a court ruling held that orthograde endo- ments and post-operative instructions to the dontic treatment was a surgical procedure requir- front desk computer with a few mouse clicks. ing written informed consent, while treatment 9. Patient is checked out: Once the patient is brought considered non-surgical in nature does not require to the departure station, they are asked the ‘‘1, 2, 3 informed consent. Conversely, courts in New Jer- questions’’: (1) The patient coordinator asks the 1494 / Endodontics

patient how they are feeling; (2) Next, the patient leadership by making them a partner in their treat- receives customized instructions, which outline ment. The relevance of your brand involves reverse their post-operative instructions and an explana- thinking. You need to ‘‘move out of your world and tion of check-up recommendations. Patients are into theirs.’’68 It is not what you are selling; it is what then appointed for their next visit and receive any they are buying, that counts! prescriptions and a patient satisfaction survey with a business reply form centered on the reverse side for mailing convenience; (3) Lastly, patients are asked to satisfy their financial obligation. DEVELOPING A CULTURE OF EXCELLENCE AROUND YOUR BRAND A business reply permit can be obtained from your The operation of the practice can be managed by local post office at a nominal cost. Patients can either asking a key question: How can I be excellent? And fill out the form immediately (highest response rate) the answer is by designing systems that allow you to or return it by mail. If patients are invited to fill out do the job right the first time. Creating a strategy to the form in the office, a box should be available for the achieve success requires five basic steps, each depen- completed survey. Because people often feel awkward dent on the preceding step to accomplish your goals. expressing their real views, this anonymity will improve compliance. 1. Step 1: Identify which patients you really want. Measuring patient satisfaction will provide two Begin with a clear understanding of who your main benefits: (1) it will allow patients to vent about patients are and which ones you want to serve. issues that will ultimately affect their loyalty and their 2. Step 2: Identify what your targeted referrers and likelihood to return for additional treatment, and (2) patients deeply value. All purchasers of services or surveys present valuable feedback about what really products want results and process quality. Finish- works and what doesn’t. All too often, we are provid- ing treatment with a pain-free and fully function- ing what we want to and not what the patient deeply ing tooth is the results part. And having a positive values. In a recent 2-year examination linking custo- experience where respect, timeliness, courtesy and mer satisfaction with purchasing behavior, and ulti- treatment with all needs (in the mind of the mately with company growth, Reichheld67 concluded patient or referrer) met on a consistent basis is that the likelihood of a customer recommending your the process quality part of the equation. services to a colleague or friend was directly related to 3. Step 3: Develop a ‘‘customer-centered focus.’’ increased growth. Learn to manage the convergence between what Patient treatment reports and other correspon- your patients deeply value and the things that you dence can be created by the front desk or assisting do best. This means that the core procedures are staff, reviewed by the practitioner, and then trans- performed in a caring and expert manner. Focus mitted to a printer and/or email client for distribution on the routine procedures that lend themselves to to referrers. It is important for the patient to list all of the highest levels of success with the most profit. their co-therapists during registration, so they will 4. Step 4: Make ‘‘creating a customer-centered focus’’ automatically receive the final treatment reports. your mission. Your mission is your ‘‘compass’’ in 10. Doctor telephones patient in evening: The last an increasingly challenging practice environment. touchpoint is the evening phone call by the This means understanding your mission and how practitioner to the patient. The value of this call each stakeholder will support and interact with the cannot be overemphasized, as it is one of the mission. Everyone needs a program that they can most appreciated services reported by patients own, but be ready to change on a routine basis. on their satisfaction surveys. 5. Step 5: Create an organization-wide obsession with Remember that patients want to be treated in a your mission. To become consistent and successful, clean and welcoming office environment. They evalu- communicate your mission to your staff, your ate your office on a continual basis, and educating referring doctors, and patients.69 In fact, brands your patients about the safety precautions you take demand consistency. According to Straine and will add value. Always assure patients that their com- Straine,70 ‘‘If your receptionist is rude, if your office fort and safety are major objectives of their treatment. manager is unhelpful when a patient needs finan- Try to explain the procedure, with permission, to the cing, if your policies are always changing, the nega- patient in terms they can understand. Use every tive impact on your brand’’ will destroy your efforts opportunity to further establish your technological to achieve clinical excellence. Chapter 41 / Operations Management in Endodontic Practice / 1495

‘‘QUALITY IN FACT’’ AND ‘‘QUALITY to a higher level.72 Many businesses spend a dispro- IN KIND’’ portionate amount of resources on a small percentage Another important concept that will help the of customers who are almost impossible to please. empathize with patients and referring doctors is the Pursuing these customers also may hurt company concept of treatment quality as viewed from the morale and will disparage the company to other patient perspective. In a look at quality, former Mal- potential patients. colm Baldridge Award examiner Patrick Townsend71 What impact will this have on an endodontic prac- defines quality in fact as goods or services that mea- tice? Referring doctors and patients who enjoy complete sure up to the specifications of the provider. For satisfaction with your services are more likely to be loyal ‘‘apostles’’ of the office than those who are just satisfied. example, when an endodontic procedure is com- 73 pleted, does it meet all of the desired specifications Professor James Hasket of the Harvard Business as defined by the practitioner? Are all of the canals School, in his ground-breaking research on the ‘‘satis- identified, cleaned, shaped, and obturated to comple- faction-loyalty link,’’ states that ‘‘if employee perfor- tely seal the root canal system? If so, then the proce- mance and loyalty is good within an organization, dure meets the specifications of the provider and then that organization’s customers will be more likely satisfies the criteria of a satisfactory case. But that is to repurchase a product or service.’’ One way to only half of the story. The other half is defined by the measure the satisfaction of your referring doctors authors as quality in kind, or the way that the patient and customers is to use a satisfaction survey. This perceives the procedure—from their viewpoint. For tool, outlined in more detail above, can point out patients, a successful visit will hinge on how the areas that you can improve, such as front desk opera- patient was treated, because the success of the proce- tions, office hours, parking, and so on. dure will be judged on the subjective quality as the Once you have identified areas that need corrective patient sees it, or the experiential aspects of their action, be prepared to create an action plan to fix the visit. And do not short change the importance of problem. Remember, a problem exists if a referring the physical environment of the office. If the office doctor or a patient perceives a problem. Problems can looks tired, patients will respond in kind, because be fixed and loyalty maintained if the problem is fixed patients will ‘‘judge the book by its cover.’’ There is quickly. It has been shown that 95% of customers will no way for most customers to even begin to assess repurchase a product or service if the problem is fixed the quality of the endodontic treatment they receive, on the spot, and 78% of customers will repurchase if they can only judge by how they were treated, the the problem is fixed within 24 hours. appearance of the office, and other non-technical Every patient and referring doctor should receive the aspects of their treatment. Take a quick mental jour- basicelementstheyexpect,likeaprofessionallyperfo- ney through your office, reception area, front desk rmed and technologically advanced procedure. Every- area, hallways, sterilization area, and operatories. Do one receives the basic support services that include they reflect your intended practice image? Are they instructions, assistance with financial arrangements, modern, clean, efficient, organized, and calm? Does it and insurance filing. Everyone gets the basic recovery send the message that your practice is up-to-date? help that includes an apology for an appointment delay Pay attention to the details—your patients and refer- or correction of a billing error. But only certain refer- rers are. Remember, you do not get a second chance rers will get extraordinary services that excel in meeting to make a great first impression. their personal preference that make the service seem customized. An example of the extraordinary services you might provide to a core referrer might be treating a UNDERSTANDING SATISFACTION patient for his or her convenience on a Saturday for A typical business customer satisfaction index is non-emergent treatment when you normally do not shown in Figure 1. If the satisfied and completely conduct business on a weekend. satisfied patients total 81%, should the directors of this company be content? Should a business concen- trate its resources on increasing the satisfaction of the PATIENT SATISFACTION SURVEYS very dissatisfied patients or try to raise the merely Patient questionnaires seek explicit information that satisfied customer to a completely satisfied level? can be analyzed and trended over time. Patient opi- Studies have shown that it is far cheaper to raise the nion surveys can help determine satisfaction with customer with a satisfaction index of from between 3.5 office personnel, procedures, or other aspects of the and 4.5 to a 5 than move a very dissatisfied customer practice which may ultimately affect patient and 1496 / Endodontics referring doctor loyalty. Opinion surveys can be cus- future, endodontists must acknowledge the enormous tomized to fit the needs of each practice and allow potential of this technology and develop sound strate- customers to vent if there are problems. gies for harnessing all its capabilities. In the larger Several options are available, each of which can be context, an Internet site can be part of your overall integrated into broader Total Quality Management identity management program that ties together all (TQM) initiatives or performance assessment strategies. marketing materials to communicate your practices Surveys can be short in-office questionnaires, with each vision. Using a professional design firm to create your patient filling out a form while in the office, or longer Web site, stationary, and brochures will ensure a coor- take-home questionnaires. Anonymity may prompt dinated look that will be more powerful than patients to be more honest with their feedback. If iden- unmatched pieces. Internet technology can enable tity is disclosed, the surveys can include call-backs to your practice to broaden the scope of patient relations patients after they have returned home. They can even and increase communications with patients, referring involve focus groups to investigate very specific ques- doctors, and study clubs. Over the last few years, the tions about programs, services, and staff. Other forms of Internet has become a unique medium for the endo- surveys include mail and email surveys, sent to a ran- dontist to promote innovative and technically sophis- dom selection of patients. These survey channels may ticated treatment. give the patient more time to complete the survey, Getting started on a Web site can be a challenging which may result in a more in-depth response. because there is a tendency to keep changing, and the The most personal way to conduct a satisfaction possibilities are virtually limitless. Here are some survey is in person or by telephone. You can have a pointers to help you get started: staff member or research professional perform the 1. The best way to begin is to visit other medical and survey. Patients can more easily elaborate on their dental provider’s Web sites. Learn how to navigate responses, but these types of surveys can be expensive. their site, what elements are required and if you want In recent research published by Press Ganey Associ- to include programs with more high-end graphic ates74 to evaluate heathcare satisfaction, patients rated effects. Simple is better, but patients and referring the courtesy, friendliness, and professionalism of the doctors will want to see some ‘‘eye candy’’ and learn dental assistant as more important than that of the on each visit. Video segments featuring you and your dentist! Infection control and cleanliness was rated staff are becoming more commonplace as video second. While the dentist’s skill was important, the technology over the Internet improves. dentist’s attention to patient anxiety and concerns 2. Decide on your goals. Is it to generate referrals via were directly related to patient loyalty and their Internet search engines, develop links to sites that potential to refer other patients. Patients also rated market dentists, or serve as a resource for your the amount of time spent with a patient and explana- patients and referring doctors? tion of treatment options as important indicators of 3. Work with Web site professionals to create a practice quality. design for your site. Remember that the design Installation of a bulletin board at your office to of the site should complement the image you are allow clinicians and staff to read each survey is an trying to project. Also, consider employing search easy way to share comments and build a consensus. engine optimization techniques to make your site Many surveys reinforce employee behavior, especially more prominent. if they mention a staff member by name. Each survey 4. Outline your proposed site and create a story- is an opportunity for your organization to improve. board that includes navigation possibilities for your audience. Design every page on a separate piece of paper and test your ideas with friends, CREATING A WEB SITE, STATIONARY, selected patients, and referring doctors. AND BROCHURE 5. Choose a Uniform Resource Locator (URL) so One of the most often neglected parts of an office that Internet address can be easily remembered branding program is the production of Internet and entered in a browser with a minimum of resources and coordinated office publications. Internet effort and confusion. The URL should tie into technology is advancing at a record pace. In every your desired image. field, including dentistry, entrepreneurs are using it 6. Then just fill in the blanks with copy, photo- to devise new and better ways to develop business graphs, and an appealing style that projects your and lower costs. To ensure brand awareness in the vision. Keep it fresh. If you want repeat visitors, Chapter 41 / Operations Management in Endodontic Practice / 1497

continually update the site and make sure your JOB DESCRIPTION links are relevant and functional. The largest cost items for most endodontic practices is employee wages and benefits.79 The plethora of reg- ulations, such as equal employment opportunity Human Resources (EEO) legislation enacted by local, state, and federal governments, has made job analysis a mandatory part Organizational success in endodontic practice requires of HR management. One of the most useful products 75 a high-performance staff. After all, your employees of comprehensive job analysis is the job description, are your brand. They must understand what your an Americans with Disability Act (AwDA) compliant brand stands for and how to deliver on your brand narrative of the major responsibilities and duties asso- 76 promise. Pfeffer and Veiga observe that ‘‘there is a ciated with each job. While most job descriptions are substantial and rapidly expanding body of evidence, limited to a single type of service or project, many some of it quite methodologically sophisticated, that endodontic offices require the use of cross-functional speaks to the strong connection between how firms team members to complete certain tasks or to fill-in manage their people and the economic results for a vacationing employee. achieved.’’ Exactly how important is marinating a A good starting point is to consult O*NET, a US well-trained and dedicated staff? Recent studies looked Department of Labor (DOL)-sponsored comprehen- at 968 firms representing all major industries and found sive source for continually updated information on that just a 7% decrease in employee turnover resulted in occupational characteristics. Based on the most cur- a per employee increase of $27,044 more in sales and rent version of the Standard Occupational Classifica- 77 $18,641 more in market value. It is clear that any tion System, each O*NET occupational title and code business, including an endodontic practice, can benefit includes descriptors for skills, abilities, knowledge, by adopting employee-related best practices to ensure tasks, work activities, work context, experience levels financial success and ultimately clinical excellence. required, job interests, and work values.80 A partial 78 According to Pfeffer and Veiga, the most important sample of O*NET’s listed tasks, knowledge, and abil- elements of a successful HR management program are ities section for dental assistants (code 31-9091.00) are (1) providing long-term job security to assure that summarized in Table 3. employee efforts will be rewarded; (2) recruiting and hiring the right people from the beginning; (3) creating self-managed project teams of peers to increase their THE STANDARD OPERATING PROCEDURE sense of responsibility and accountability; (4) providing Often overlooked but extremely valuable, the standard high compensation that is contingent on performance; operating procedure (SOP) is a written practices and (5) investing in extensive training for all employees; (6) procedures reference, which is designed to ensure that reducing status differences between employees to key procedures are performed in a safe and compliant improve idea generation from all employees; and (7) manner. The SOP is typically written by the current teaching information sharing to create a high-trust job holder and edited by the practice administrator.81 organization that allows inclusiveness. SOPs force employees to think through a procedure 1498 / Endodontics

Table 3 Tasks, Knowledge, and Ability Tasks Importance Category Tasks

99 Core Prepare patient, sterilize and disinfect instruments, set up instrument trays, prepare materials, and assist dentist during dental procedures 92 Core Expose dental diagnostic X-rays (certification may be required) 90 Core Record treatment information in patient records 88 Core Take and record medical and dental histories and vital signs of patients 88 Core Provide post-operative instructions prescribed by dentist 87 Core Assist dentist in management of medical and dental emergencies 77 Core Instruct patients in oral hygiene and plaque control programs 79 Supplemental Apply protective coating of fluoride to teeth 76 Supplemental Schedule appointments, prepare bills and receive payment for dental services, complete insurance forms, and maintain records, manually or using computer

Importance Knowledge

87 Medicine and Dentistry—Knowledge of the information and techniques needed to diagnose and treat human injuries, diseases, and deformities. This includes symptoms, treatment alternatives, drug properties and interactions, and preventive healthcare measures 73 Customer and Personal Service—Knowledge of principles and processes for providing customer and personal services. This includes customer needs assessment, meeting quality standards for services, and evaluation of customer satisfaction 64 English Language—Knowledge of the structure and content of the English language including the meaning and spelling of words, rules of composition, and grammar 59 Clerical—Knowledge of administrative and clerical procedures and systems such as word processing, managing files and records, stenography and transcription, designing forms, and other office procedures and terminology 51 Chemistry—Knowledge of the chemical composition, structure, and properties of substances and of the chemical processes and transformations that they undergo. This includes uses of chemicals and their interactions, danger signs, production techniques, and disposal methods 42 Computers and Electronics—Knowledge of circuit boards, processors, chips, electronic equipment, and computer hardware and software, including applications and programming 40 Psychology—Knowledge of human behavior and performance; individual differences in ability, personality, and interests; learning and motivation; psychological research methods; and the assessment and treatment of behavioral and affective disorders 40 Public Safety and Security—Knowledge of relevant equipment, policies, procedures, and strategies to promote effective local, state, or national security operations for the protection of people, data, property, and institutions 36 Mechanical—Knowledge of machines and tools, including their designs, uses, repair, and maintenance

Importance Ability

78 Oral Expression—The ability to communicate information and ideas in speaking so others will understand 75 Oral Comprehension—The ability to listen to and understand information and ideas presented through spoken words and sentences 72 Near Vision—The ability to see details at close range (within a few feet of the observer) 72 Written Expression—The ability to communicate information and ideas in writing so others will understand 66 Information Ordering—The ability to arrange things or actions in a certain order or pattern according to a specific rule or set of rules (e.g., patterns of numbers, letters, words, pictures, and mathematical operations) 66 Speech Clarity—The ability to speak clearly so others can understand you 62 Arm-Hand Steadiness—The ability to keep your hand and arm steady while moving your arm or while holding your arm and hand in one position 60 Speech Recognition—The ability to identify and understand the speech of another person 56 Finger Dexterity—The ability to make precisely coordinated movements of the fingers of one or both hands to grasp, manipulate, or assemble very small objects 56 Problem Sensitivity—The ability to tell when something is wrong or is likely to go wrong. It does not involve solving the problem, only recognizing there is a problem 56 Selective Attention—The ability to concentrate on a task over a period of time without being distracted 56 Written Comprehension—The ability to read and understand information and ideas presented in writing 53 Flexibility of Closure—The ability to identify or detect a known pattern (a figure, object, word, or sound) that is hidden in other distracting material 53 Manual Dexterity—The ability to quickly move your hand, your hand together with your arm, or your two hands to grasp, manipulate, or assemble objects

Table 3 continued on page 1499 Chapter 41 / Operations Management in Endodontic Practice / 1499

Table 3 continued from page 1498

53 Time Sharing—The ability to shift back and forth between two or more activities or sources of information (such as speech, sounds, touch, or other sources) 50 Category Flexibility — The ability to generate or use different sets of rules for combining or grouping things in different ways 50 Control Precision—The ability to quickly and repeatedly adjust the controls of a machine or a vehicle to exact positions 50 Deductive Reasoning—The ability to apply general rules to specific problems to produce answers that make sense

National wage and employment trends

Category Occupation information

Employment (2004) 267,000 employees Projected growth (2004–2014) Much faster than average (36+ %) Projected need (2004–2014) 189,000 additional employees

A partial list of the tasks, knowledge, and ability associated with dental assisting is reproduced above. Adapted from O*NET Web site http://online.onetcenter.org/link/ details/31-9091.00, accessed May 1, 2007. O*NET is a service of the U.S. Department of Labor and acts as a comprehensive source of ranked descriptors for more than 900 occupations. step by step and are in themselves useful training professional advice from your attorney, accountant, or a tools. More complex tasks lend themselves to the personnel advisory firm, so that personnel procedures SOP structure for training new employees and mod- are documented before contentious issues arise. Person- ifying procedures to improve efficiency and safety. nel advisory firms can provide comprehensive and cost- While SOPs work well for procedures that require effective help and implementation, providing excellent safety and standardization, they may limit creativity handbooks, supporting resource manuals, and technical where imagination is warranted. The best approach is assistance. The ADA also sells a hand-book resource to be concise and make the document as dynamic as manual with step-by-step guidance. possible. SOPs should be easily accessible to all Courts generally view both verbal and written policies employees via the practice’s computer network and as a contract. However, unwritten policies may pose at a minimum should be updated on an annual basis. more risk than written policies, because verbal policies Each SOP should have a header with the title, either can be implied or given by someone with no original issue date, revision dates, number of pages, authority. Written handbooks help avoid conflict by the author of the SOP, and ‘‘approved by’’ signature reducing the chances of a dispute between you and plus the following basic elements (Table 4): employee, especially in the most litigious areas of firing and discipline. It is critical that your handbook is prop- 1. Desired outcome erly vetted by knowledgeable advisors, because, as Peter 82 2. Definitions Sfikas, ADA general council notes, courts ‘‘have deter- 3. Measurement mined that manuals, handbooks and booklets can create 4. General information implied employment contracts, subjecting the employer 5. Step-by-step procedure with identification of cri- and employee to additional terms and conditions of tical information employment.’’ In the interest of both the employer 6. Attachments and forms to be used, if any and the employee, written handbooks that clearly state the policies of the practice serve to minimize the risk of CREATING THE EMPLOYEE HANDBOOK litigation, and well-drafted disclaimers may help to maintain the ‘‘at will’’ status of employees. Generally, a Employee handbooks help to establish the employer’s clear statement at the beginning of the handbook stating expectations and can prevent misunderstandings that that the handbook is not a contract and that the policies may reduce the risk of litigation. Because most employ- therein can change at any time without advanced notice ees want to be successful, they will generally welcome a will provide some measure of protection. description of expectations, procedures for obtaining a According to the U.S. SBA,83 an employee hand- promotion or raise, policies on dress, leave requests, book should include the following: work hours, disciplinary issues, and other important guidelines. The process involved in creating a handbook 1. Overview of practice philosophy and history can also help you think through and establish your own 2. Equal opportunity statement that hiring, promo- unique policies. To aid in the process, consider getting tion, pay, and benefits are not related to employee’s 1500 / Endodontics

Table 4 Standard Operating Procedures: Computers Desired Outcome: All computer equipment in the Practice will operate efficiently to create and store all radiographic and visible light images, clinical charts, patient financial transactions, appointments, protected health information (PHI), and other materials related to the Practice. Patient confidentiality will be maintained in accordance with the Practice’s current Health Insurance Portability, and Accountability Act (HIPAA) Manual and office policies. Definitions: Information technology (IT) refers to the use of computers and computer software to manage office information. Measurement: Evaluation of internal and external customer satisfaction by ‘‘Employee Evaluation of Office’’ and ‘‘Patient Satisfaction Survey.’’ Internal customers will experience infrequent computer down time, undergo adequate training, and use programs that do the intended job right the first time. Introduction: All computer systems in the office are critical to the success of the Practice. The Practice stores all clinical and administrative data on the office computer system. Therefore, the Practice’s computers and networks are to be used for Practice-related work only. No expectation of privacy: In the course of operation and maintenance activities, use of computers and networks may be monitored to ensure the continuing effectiveness and integrity of the Practice’s IT resources. Email, Web logs and data, and other files created or received while using the Practice’s computers are neither private nor confidential. The Practice reserves the right to access and disclose all messages sent by its computers and networks, as well as any data created, received, or stored on them. Computer security and access to files and email: Although the Practice intends to convey no expectation of privacy, its business communications must be protected from unauthorized access. At no time may any employee remove or transfer any data to computers outside of the office by any means, including disks, jump-drives, CD-ROMs, or the Internet for any reason. Employees are not to give any computer information to anyone on the telephone who calls our office without specific permission from Dr. Levin or Dr. Lee. The only exception is our IT services company. No disks, CD-ROMS, or other material of any kind can be brought from the home of an employee and placed on the Practice’s computer systems at any time. Patient confidentiality: see HIPAA Manual and office policies as published periodically. Internet use: No employee is allowed to use the computer system for personal use at any time. Web: When using the Web, only the approved Internet browser is permitted. Approved sites include only those directly related to the business of the Practice. Email: Only MS Outlook, Google, and Yahoo are approved for email use. Any email messages generated or viewed at the office are the property of the Practice. Virus protection: We use McAfee Enterprise virus protection, which automatically updates all of our workstations every night via the McAfee Web site and our LAN. All computers will be running McAfee virus protection at all times. This will protect our system from virus destruction and other potentially harmful computer intrusions. Confirm that this software is active at start-up and remains active at all times. Firewall protection: We are protected from hackers through our Internet switch called WatchGuard ‘‘Firebox.’’ Make sure this equipment is on at all times. Backup: We use a tape backup system, located in the server. Each business day, a numbered tape is placed in the server and noted on the ‘‘Backup Log’’ by the operator’s initials. Every Friday, the cleaning tape is placed in the tape drive, allowed to complete one cycle that takes approximately 1 minute, and is removed from the drive. On Monday, the Friday night tape is placed on Dr. Levin’s laptop bag for off-site storage. Passwords: Each employee will be issued a discrete user name and password to log into EndoVision. As there are nine levels of security, some codes will not allow every user to perform all tasks. SQL: EndoVision (EV) and Schick (CDR) use their own database engines that reside on the server. This SQL database software must be active on the server to allow workstation access to EV and CDR. Both of these SQL database engines will be running on the ‘‘Taskbar’’ of the server. If you cannot login from any workstation for either EV or CDR, check the server to see if their individual SQL database engines (icons in the taskbar) are active. PC software and hardware controls: Users may not download, purchase, or install software or hardware on office computers unless it is approved by Dr. Levin or Dr. Lee Copyrighted and licensed materials may not be used on a PC or the Internet unless legally owned or otherwise in compliance with intellectual property laws.

Critical information is italicized.

race, color, religion, sex, age, disability, or national time to advise employees of unsatisfactory origin. work. 3. Work hours should be defined, including time for 6. Paid holidays and all types of leave, including lunch and conditions that could require late family (maternity, adoption, and elder care), med- hours, such as treating after-hours emergencies. ical, dental, funeral, personal, jury, and military 4. Wage policies should include general information should be listed. about when paychecks will be issued, how and 7. A termination section should inform employees when promotions are handled, classification of about causes that will trigger firing, including part-time, full–time, and on-call employees, over- criminal activity, insubordination, absenteeism, time, loans, and leaves without pay. and poor work performance. 5. The performance review section should describe 8. All forms should be included, such as sample how and when employees will be evaluated; requests for vacation, medical leave, hepatitis vac- unscheduled evaluations may be made at any cination declination, and so on. Chapter 41 / Operations Management in Endodontic Practice / 1501

9. Acknowledgement of receipt and reading of coincide with the date of hire for each employee, will handbook by employees should be required by help improve compliance by the practice. the practice and kept in the employee’s personnel folder or other secure location. Employee handbooks should be written by a lawyer EMPLOYEE SELECTION CRITERIA specializing in employment law or by consultants who What are the predictors of the best job performance? In provide HR advice. A poorly written handbook may an article reviewing 85 years of the practical and theo- contain legal pitfalls that can lead to litigation. The retical implications of personnel psychology, research- following suggestions may help avoid some common ers Schmidt and Hunter86 have shown that, on average, errors: intelligence or general mental ability (GMA) is the most useful primary personnel measure for hiring deci- 1. A statement that conforms to your state’s sions when compared to all other attributes, including ‘‘employment-at-will’’ doctrine, which specifies conscientiousness. The positive economic effects of that employment can be terminated at any time, assessing an applicant’s intelligence and hiring only for any reason, or no reason at all, will generally the top performers cannot be overestimated. Further- provide some measure of protection against suc- more, this study states that performance in a skilled job cessful litigation. Good advice here is critical, will benefit more from a higher GMA than perfor- because construction of the document, obtaining mance in a semi-skilled job. It turns out that people written acknowledgement by the employee, public with a high GMA scientifically correlate with conscien- policy exceptions, situations where an expressed tiousness, agreeableness, and emotional stability.87 or implied employment contract exists, and Other studies have demonstrated that while intelligence ‘‘situations where an implicit duty of good faith is the best single predictor of performance, screening exists in the employment relationship’’ can lead to employees for how well their values fit with their confusion and ultimately to litigation.84 employer’s values (value fit) is also a predictor of 2. Announcing a ‘‘probationary period’’ of employ- employee satisfaction and retention. However, when ment may wrongly imply that employees are interdependent tasks were measured against non-inter- entitled to continuing employment after the pro- dependent tasks, value fit predicted only better citizen- bation period is over. ship behaviors, not higher performance.88 3. Employee manuals should not include benefit Of course, the success of your practice will depend, plan documents, but simply point employees in part, on the people you hire. Ritz-Carlton hotels toward other documentation. use an elaborate system for assessing job candidates, 4. Do not outline specific pre-firing procedures, and the qualities the company believes are crucial to because courts have held employers liable for its success. When Paul Hemp,89 a senior editor at the ‘‘wrongful termination when those steps were not Harvard Business Review, spent a week at the hotel as a followed.’’85 room-service waiter, he went through the new 5. Generally, paychecks must be paid within a spe- employee interview to see if he was the kind of candi- cified time limit, so be sure to specify these guide- date the Ritz was looking for. He said that ‘‘even after lines in accordance with local wage and hour fudging my answers to a few questions, I got only ten laws. points out of a possible fifteen in the composite hos- 6. Ensure that employees sign an acknowledgement pitality assessment.’’ The interviewer told Hemp that that they have received, read, and agreed to the a score of 10 was not bad, but they wanted someone provisions of the handbook. Otherwise, an with a score of 12. He later found that just taking care employee may claim that he or she never received of his sister in a time of need was not an extraordinary the manual. example of caring, but if he had given her his house 7. Limitations on employee–employee communica- for a month, he would have earned a higher score. tions about wages or benefits are not allowed. Using scientifically based criteria, the Ritz has mana- The employee handbook should be a positive tool ged to reduce its annual employee turnover from the for promoting better communication and improving industry average of 55 to 28%! morale. Be sure to review the handbook at least Surveys that rank the importance of pay is another annually to be sure it is consistent with office policies. area of interest for the endodontic practice. Research Also, annualizing employee performance reviews, raises has shown that self-reports of pay significance are and updating state and federal withholding forms to likely to ‘‘underestimate its importance due to norms 1502 / Endodontics that view money as a somewhat crass source of moti- It may also be helpful for you to conduct brief vation.’’90 But money speaks, and getting the right telephone interview with each of the remaining can- combination of remuneration and benefits will posi- didates. Asking a few open-ended questions like ‘‘Tell tively impact your practice. me about your recent job experience’’ may help to However, be certain to have any pre-employment identify those applicants you deem worthy of further exams or surveys thoroughly reviewed by an attorney consideration and will provide an opportunity for the or HR consultancy in order to ensure that it does not candidate to ask questions to determine whether they unintentionally skew results that disfavor applicants believe the job is right for them. After a positive based on their protected EEO classes. phone conversation, invite the candidate for a face- to-face interview. Have a job application form ready for the new candidate and make sure it includes appropriate lan- HIRING THE BEST PERSON FOR THE JOB guage authorizing reference checks. Notifying the can- The hiring process should begin only after creating a didate of your intention to check references gives the set of job descriptions and an employee handbook. candidate time to alert contacts to expect your Once these documents are created, the next step is inquiry. If you want to know what the prospective placing a job announcement in the print or online employee is really like, contacting his or her former media or contracting with an employment agency. employers may be the best way to find out. Many Typically, the Internet will produce same-day results companies check references as the final part of their and can be placed free of charge or on fee-based sites. hiring process, and sometimes extend job offers with An example of a job announcement for a Patient the condition that references check out. Using a refer- Coordinator written for Craig’s List, a popular online ence request form with a waiver signed by the pro- listing service follows: spective hire is a good way to safely get the informa- Dental specialty office has immediate opening for a tion. Try contacting former employers et al. at more Patient Coordinator with a friendly attitude. If you than one company, if possible, to get the broadest share our vision of a customer-centered focus with a picture of the candidate. It is best to restrict questions high-tech approach, this is the job for you! We are to those that relate to education, training, experience, looking for someone who is a team player and enthu- qualifications, job performance, professional conduct, siastic (someone who likes to smile). You will need and reason for termination. excellent telephone and customer service skills. Profi- Check with your attorney or HR consultancy to ciency with MS Word and Excel is required. Respon- make sure that you are in compliance with state sibilities include answering the phones, scheduling, employment laws. To ensure that the information and welcoming new patients, billing, and organizing exchanged is from a legitimate former employer, try practice promotion activities. using fax or mail to verify the information. To help This position requires some schedule flexibility as make the process a little less litigious, many states patient appointments may occasionally extend the have enacted legislation providing some immunity workday. Our usual hours of operation are Monday from civil liability for providing information about to Friday 8:15 am until 5:15 pm. Employee handbook the employee. Also, many employers have their own and complete benefits package including medical and policies regarding reference checks on current and parking await the right candidate. Please email your former employees that restrict the information they resume without attachments (cut and paste into body divulge to position title and dates of employment. If of email). you encounter such a response, do not automatically When candidates respond to the job announce- assume that the applicant had a negative employment ment, a pre-interview screening of the applications experience with their previous employer. by the person in charge of personnel can help in The purpose of the initial interview is to form an choosing the best qualified candidates. Ideally, the impression of how the candidate will fit into the screener should review the applications for basic practice culture, confirm his or her technical skills, objective criteria and reject those that do not possess and narrow down the field of applicants. Keep a the minimum education, experience, or skills set. record of the conversation, with each question and Having a formal intermediary step in the screening answer documented for future reference. Always meet process may help insulate against litigation because it candidates at your office during regular business will interject an objectively neutral perspective into hours with other staff on premises during the entire the hiring process that can mitigate any claims of bias. meeting to preclude any chance of allegations of Chapter 41 / Operations Management in Endodontic Practice / 1503 inappropriate behavior. Unfortunately, many inter- Always avoid asking about the applicant’s immigra- viewers are improperly trained or uninterested in tion or citizenship status. Although it will be neces- meeting with applicants. Nonetheless, endodontic sary for the applicant to establish that they are law- practices, like other small businesses, need to adhere fully permitted work in the United States, questions to good hiring practices or hire employees through regarding the specific immigration status of the appli- employment agencies. Because many questions can cant can give rise to national origin discrimination open the door to non-job-related information that claims. It is permissible to ask the applicant the yes or may be illegal, try to formulate behavioral questions no question ‘‘are you lawfully permitted to work in guided by the job description. Having this list of the United States?’’ questions ready will ensure that you get the precise Interviewers should avoid any assurances related to information you need every time. Examples of good job security. Assuring the interviewee that they will questions to ask are the following: ‘‘have their job for as long as they do a good job’’ is fraught with risk. If the applicant accepts the job and 1. Tell me about a time when your teamwork with a 6 months later is laid off, a breach of contract claim co-worker helped you meet a patient’s needs. could be filed, where the employee asserts that he or 2. Give me an example of a mistake you made while she cannot be terminated unless they did not do a carrying out your job duties. What happened? good job. How did you correct the mistake? Once an offer of employment has been extended 3. Tell me the procedures used for sterilizing a treat- and the candidate has accepted the offer, a welcome ment setup. packet of office information should be presented. This 4. What steps do you take to ensure patient and packet can include a welcome letter, employee hand- operator safety when working with a patient? book, a listing of compensation and benefits, Asking the right questions allows you to control the employee roster, hepatitis vaccination verification or interview and helps to make certain that the interview declination form (if applicable), health insurance is legally compliant.91 It is important that you ask the application, payment options, retirement plans (if same questions for each candidate during the hiring applicable), and any other information deemed process to ensure that each applicant is treated important for the new employee. In addition, federal equally. and state withholding forms, along with the Depart- Remember that there are areas where caution ment of Homeland Security, U.S. Citizenship and should be used in making pre-employment inquiries. Immigration Services’ Employment Eligibility Verifi- cation form must be completed within 3 business days Whether asked on an application form or in an inter- 93 view, the EEO Commission and state Departments of of the employment commencement date. Labor will consider some questions as evidence of discrimination, unless the employer is able to show POSTING OF EMPLOYEE NOTICES that the inquiries are job-related or that there is a The US DOL94 and all states including the District of documented business-related necessity for asking the Columbia require that notices be provided to question. Partial list of subject areas to avoid during employees and/or posted in the workplace where interviews:92 employees can readily observe them.95 Designating 1. Arrest records a wall area in the employee locker room or break 2. Garnishment records room will provide an ideal place for a bulletin board 3. Marital status to post periodic notices to staff and federal and state 4. Child-care provisions posters. DOL provides free electronic and printed 5. Contraceptive practices copies of these required notices and posters at the 6. Pregnancy and future childbearing plans ‘‘elawsÒ Poster Advisor’’ on the DOL Web site.96 7. Physical or mental disabilities State posting requirements can be determined by 8. Age, height, and weight contacting your state DOL through the links page 9. Nationality, race, or ancestry located on the DOL Web site. In addition, some 10. Other areas of potential discrimination include states, like California, require distribution of pamph- certain limiting physical requirements, availability lets, such as the State Disability Insurance and Paid for weekend work, appearance standards, and Family Leave pamphlets, to employees under certain fluency of the English language circumstances.97 1504 / Endodontics

EMPLOYEE BENEFIT AND SALARY There are several important laws governing salary ADMINISTRATION and benefits compensation packages. The Fair Labor Compliance with statutory wage and hour require- Standards Act (FLSA), the Employee Retirement ments is one of the areas that endodontic practices Income Security Act (ERISA), and the (HIPAA) may find confusing, that is, hourly versus salaried impose a myriad of complicated rules and regulations compensation or complying with wage and hour governing retirement plans, health insurance, cafeteria requirements for staff travel to and attendance at plans, and other benefits of employment. It is impor- continuing education meetings. Be sure to check with tant that you seek guidance from a plan benefits advi- your HR advisors to determine the best policy. sor and attorney or HR consultant in deciding how to Many practices use outside services for payroll pro- structure your employee salary and benefits packages. cessing and tax filing (i.e., W-2 and 1099 annual filing), reducing the chance of errors and incorrect filing of federal and state taxes. According to a recent TERMINATION study, the average small business that ‘‘ran payroll in- Few practice owners or managers want to face the house and filed and paid quarterly taxes manually emotionally charged process of firing people. Termi- spent more than 250 hours away from customers . . . nating employees in a way that preserves their dignity doing these tasks.’’98 Offering direct deposit of wages while preventing costly mistakes will benefit both the to each employee’s own bank account is an additional employee and the practice. The actual termination way to improve security and encourage staff members process will stay in everyone’s mind for a long time to maintain individual privacy and avoid salary com- and speak volumes about the practice. At best, a parisons. Direct deposit has the added advantage of successful termination can make the employee a ensuring that wages are available to employees as friend of the practice and in the worst scenario can quickly as possible. No one benefits by stressed-out result in a costly legal process. A termination will also staff members leaving the office during the business affect co-workers if not handled properly, even if the day to deposit their payroll checks. Check your state employee is not well liked. Remember that in most wage and hour laws to determine if you can require jurisdictions, employees have the right to claim direct deposit before mandating this service. Some unemployment benefits which will often raise the new endodontic practice management software even practice’s tax rate. The burden of proof is almost includes timesheets with biometric fingerprint identi- always on the practice to prove the reason for the fication technology. separation in unemployment claims cases. Additional information is available from the Amer- Even after carefully vetting new employees, he or ican Dental Assistants Association, ADA, Dental she may not meet your expectations or may even act Assisting National Board, Inc. and the DOL, Bureau illegally. As soon as performance or discipline pro- of Labor Statistics, on the national estimates for den- blems become apparent, start documenting your tal assistant wages, including industry and metropoli- communications with the employee in question. tan area profiles for this occupation (Table 5). Before terminating an employee, review your

Table 5 Dental Assistant Wages Employment Employment RSE Mean Hourly Wage Mean Annual Wage Wage RSE

270,720 1.3% $14.41 $29,970 0.6% Percentile wage estimates for this occupation

Percentile 10% 25% 50% (Median) 75% 90%

Hourly Wage $9.46 $11.53 $14.19 $16.92 $20.21 Annual Wage $19,680 $23,980 $29,520 $35,190 $42,030

Employment estimate and mean wage estimates for all categories of dental assistants, (31-9091) for May 2005 (Adapted from http://www.bls.gov/oes/current/ oes319091.htm, accessed March 2, 2007). According to the Dental Assisting National Board, certified dental assistants earn higher wages than those who are not certified (Adapted from http://www.dentalassisting.com, accessed March 2, 2007). Chapter 41 / Operations Management in Endodontic Practice / 1505 employment offer letters, company policies, hand- Although this list is not complete, it is a good start- books, and performance reviews to assure compliance ing point to consider when dealing with employee with the practice’s policies. If an employee performance misconduct. review was conducted, exercising special care will help In sensitive firing situations or if terminating an reduce the chances of litigation in the following situa- employee is new to you, consult with an experienced tions: (1) when firing someone who has filed prior employment lawyer or labor advisor ahead of time to complaints about harassment or Occupational Safety prepare what to say, understand state laws that govern and Health Act (OSHA) violations; (2) is older than 40 termination, and have all paperwork, salary checks, and covered by the Age Discrimination in Employment and severance pay ready to give to the employee. Act (ADEA); (3) is a member of a minority group Always keep all discussions confidential and document because of race, color, gender, religion, or national the termination to aid in future communications with origin; (4) has an employment contract; (5) has been any state or federal agencies. Be prepared to answer the promised job security or long tenure; and (6) if you are employee’s questions about their schedule, severance laying off more than one employee at once. In all cases, pay, references, what will co-workers be told, medical every employee must be treated even-handedly. and other insurance benefits, keys and security cards, In determining whether to discipline or terminate profit sharing plan, if any, and eligibility for unem- an employee, it may be helpful to consider various ployment insurance. factors to preserve objectivity. Consider the following: Conducting an exit interview is another way to improve the work environment for the practice. Exit 1. The nature and seriousness of the offense and its interviews should be conducted separately from the relation to the employee’s duties, position, and termination meeting and in small practices can be a responsibilities, including whether the offense was simple survey to be mailed back or a phone conversa- intentional, technical, inadvertent, malicious, for tion. Explain that the purpose of the interview is to personal gain, or was frequently repeated. gather information about the employee’s experience 2. The employee’s job level and type of employment, at the practice and how it treats employees. Be sure to including supervisory or fiduciary role and con- set the right tone, stay objective, and listen without tacts with customers. providing opinions or becoming defensive. 3. The employee’s past disciplinary record. 4. The employee’s past work record, including length of service, performance on the job, ability to get along with fellow workers, and dependability. EMPLOYMENT LAW 5. The effect of the offense upon the employee’s Many dentists assume that as they are practicing in an ability to perform at a satisfactory level and its ‘‘at-will’’ state, they can discharge employees at any- effect upon supervisors’ confidence in the employ- time without problems. In certain circumstances, ee’s work ability to perform assigned duties. other issues can supersede the ‘‘at-will’’ prerogative, 6. Consistency of the penalty with those imposed like violating an employee’s civil rights. For example, upon other employees for the same or similar the practice cannot discriminate against an employee offenses. who belongs to a protected class, where issues regard- 7. The notoriety of the offense or its impact upon ing age, sex, race, color, religion, disability, or national the reputation of the practice. origin may play a role. Get the advice of legal council 8. The clarity with which the employee was on or your HR advisory firm if you plan to discharge an notice of any rules that were violated in commit- employee whose dismissal may trigger other issues. ting the offense or had been warned about the It is best to administer your employment practices conduct in question. in a fair, equal, and consistent manner by counseling 9. The potential for the employee’s rehabilitation. and documenting disciplinary and performance pro- 10. Mitigating circumstances surrounding the offense blems in written form. Include specific comments such as unusual job tensions, personality pro- (i.e., reason for counseling, nature of disciplinary blems, mental impairment, harassment, or bad action, corrective action expected, consequences of faith, malice or provocation on the part of others non-compliance, and employee and employer com- involved in the matter. ments) that are dated and signed by the administra- 11. The adequacy and effectiveness of alternative tor, employee, and a neutral witness, if possible. Never sanctions to deter such conduct in the future by include an employee’s co-workers or peers in the the employee or others. termination process.99 1506 / Endodontics

The following suggestions may help avoid common for 3 years with respect to payroll and demo- legal pitfalls graphic information as well as information related to the individual employee’s leave of 1. Maintain two types of personnel files for each absence. employee, regular and confidential. The I-9 form 8. IRS: IRS rules require keeping copies of employ- should be kept in the confidential file and should ment tax records (Social Security documents) for not be given to anyone for inspection without 4 years after the due date of the tax. If a claimant legal advice. The I-9 form should be kept for 3 files a claim, the retention period should extend years from date of hire or 1 year from termina- for 4 years after the date of the filing. (26 CFR tion, which ever is longer. 31.6001). 2. Have an established protocol to follow when an employee or former employee or their attorney Other employment law issues to be aware of asks to review his or her personnel file. include the following: 3. Have a signed employment handbook with each 1. The Uniformed Services Employment and Reem- employee. ployment Rights Act (USERRA): USERRA 4. Prohibiting employees from talking about their requires employers to hold available the position wages or benefits is not allowed under the of employees who are active reservists called for National Labor Relations Act which specifies the duty. This includes short-term assignments for right of employees at all workplaces, unionized or training which may only require a few days of not, to engage in collective bargaining. leave, or long-term active duty in times of con- 5. To protect the privacy of employees, keep all flict. Additional guidance may be found at the employee files locked or off-site. Records in many DOL Web site at http://www.dol.gov/elaws/ states can only be disposed of by destruction, userra.htm. modification, or other reasonable action to pro- 2. The Pregnancy Discrimination Act: An amendment tect personal information.99 to Title VII of the Civil Rights Act of 1964, the 6. Employee records must be maintained on the fol- Pregnancy Discrimination Act prohibits an lowing schedule.100 OSHA: OSHA requires that employer from treating an employee who becomes records of job-related injuries and illnesses be kept pregnant differently than any other employee with for 5 years. Employers are also required to fill out a serious medical condition. For example, if your and post an annual summary. Any exposure to practice grants extended leave (either paid or toxic substances and blood-borne pathogens along unpaid) to an employee recovering from a heart with any records related to medical exams must be attack, you must grant the same consideration to a retained for 30 years after termination of employ- pregnant employee. Keep in mind, that pregnant ment. FLSA: Under the FLSA, the record-keeping employees may also have additional rights under requirements are 3 years to cover both supplemen- the Family Medical Leave Act. tary basic records and payroll records. Civil Rights 3. Sexual Harassment: It is imperative that your Act of 1964, Title VII, ADEA and the Americans practice have a strongly worded written policy with Disabilities Act (AwDA): Under the Civil stating that sexual harassment will not be toler- Rights Act of 1964, Title VII, and the AwDA, ated. It should include a provision that employees employers with at least 15 employees must retain who report sexual harassment will not be reta- applications and other personnel records relating liated against and notify them of a confidential to hires, rehires, tests used in employment, promo- process for reporting any instances of harassment. tion, transfers, demotions, selection for training, You should take prompt and remedial action in layoff, recall, terminations of discharge, for 1 year addressing any allegations of harassment includ- from making the record or taking the personnel ing investigating the claims, separating the person action. The ADEA requires the retention of the who reported the harassment from the alleged same records for 1 year for employers with 20 or harasser, and taking any necessary disciplinary more employees. Title VII and the AwDA require actions. For more information, please refer to that basic employee demographic data, pay rates, the U.S. Equal Employment Opportunities Com- and weekly compensation records be retained for mission (EEOC) guidance at http://www.eeoc. at least 1 year. gov/policy/docs/harassment.html. 7. Family and Medical Leave Act (FMLA): The 4. Local Laws: Local laws may expand or modify FMLA requires the retention of certain records Federal employment statues, so it is necessary that Chapter 41 / Operations Management in Endodontic Practice / 1507

you consult with an attorney or HR consultancy or require arbitration. Before purchasing coverage, to become aware of any additional requirements. carefully review limitations and exclusions to make For example, some jurisdictions also prohibit dis- sure the policy fits your needs, as follows: (1) find out crimination on the bases of sexual orientation what is covered in addition to wrongful termination, and/or political affiliation. harassment, and discrimination, such as invasion of privacy, negligent supervision, and hiring issues; (2) CONFIDENTIALITY AND check to see if the policy will cover claims made by NON-COMPETITION COVENANTS current part-time or temporary employees, indepen- dent contractors, and the EEOC; (3) confirm that you Some employers require employees to sign non-com- can choose your legal defense team; and (4) choose a pete covenants and confidentiality clauses. Generally, carrier that has a solid track record in the field. non-competition covenants with administrative or clerical staff will be held invalid. Some firms may legitimately enter into non-competition clauses with WORKERS’ COMPENSATION associates or other professional staff within their prac- Workers’ compensation provides wage replacement tice so long as they are for a limited duration (1 or 2 benefits, medical treatment, vocational rehabilitation, years); not overly restrictive (limited to a specialty and other benefits to certain workers or their depen- practice and not the entire medical or dental profes- dents that experience work-related injury or an occu- sion); and of a limited geographic scope (a few mile pationally related disease. Workers’ compensation radius of the current practice location). Keep in mind claims can be minimized by ensuring a safe workplace state laws and professional ethics rules may bar any and making sure employees are capable of performing non-compete covenants. their jobs before they are hired. Employers cannot ask Contrary to covenants not to compete, confidenti- about a prospective employee’s Workers’ compensa- ality clauses can be enforced so long as they pertain to tion history before a job offer is made. proprietary procedures or information and patient Whenever a work-related injury occurs, make sure medical information. Consult with an attorney if that an accident report is completed and a notifica- you are considering either covenant. tion is provided to your Workers’ compensation insurance provider. Any work-related injury that EMPLOYMENT LIABILITY PRACTICES occurs over a period of time, like carpal tunnel syn- INSURANCE drome or hearing loss, must be reported by the employee as soon as he or she learns that it is work- Liability arising from employment practices continues related. an upward trend that shows no signs of abating. Unlike comprehensive general liability (CGL) policies, which insure against claims for tangible damages, for STAFF MEETINGS AND PEAK example, property damage, employment practices lia- PERFORMANCE bility insurance (EPLI) insures against claims arising As the U.S. demographic picture continues to change, from employment practices. CGL policies differ from and the population/dentist ratio exacerbates health- EPLI policies by excluding intentional acts and bodily care manpower shortages, especially in rural and injury that might occur while working. Also, CGL underserved areas, there has never been a greater need policies cover claims made while the policy is in effect, for the dental team to work more efficiently. Dental even if the claim is brought years later, whereas EPLI practices must not only ‘‘provide optimum patient will cover only claims made during the coverage per- care, but also must operate as a profit-making busi- iod or claims that the employer knew about or should ness’’101 to ensure the ability to upgrade facilities and have known about during the coverage period. acquire new technologies and training Many EPLI policies include wording that requires Along with hiring the right people, using meetings the insurance carrier to defend the employer against to enhance peak performance and improve service claims, even if the deductible has not been met. How- quality are the hallmarks of a well run office. The ever, these clauses allow the carrier to choose the ‘‘morning huddle,’’ a 10- to 15-minute briefing, facili- attorney who will defend the employer against the tated by the patient coordinator, is a valuable way to claim. Some policies also contain a provision that keep up-to-date on patients, procedures, scheduling, allows the carrier to settle the case, and if the upcoming events, and miscellaneous matters. As a employer rejects the settlement offer, the carrier can group, determining the best place to schedule emer- limit its liability to the amount offered in settlement gency patients and share suggestions about how to fill 1508 / Endodontics appointment openings will improve efficiency and advice must be tailored to the specific circum- reduce stress. The agenda should include a brief stances of each case. Nothing provided herein review of production and collections from the pre- should be used as a substitute for individual endo- vious day, expected for the current day, and the dontic or dental management advice. Laws vary month, along with some time to discuss operational considerably from jurisdiction to jurisdiction, and issues that need attention. Try to end on a positive even within jurisdictions. Therefore, some informa- note, adding a birthday or anniversary acknowledge- tion may not be correct for a jurisdiction or locale. ment, a joke or a complement.102 Regular staff meetings are another way that prac- tices stay ahead. Start by creating a file for staff to References place suggestions and complaints between meetings (a word processing file accessible to all computers on the 1. Lavers JR. Market trends in dentistry. Dent Econ network will be helpful). Make the meetings a safe 2002;92:64–72. environment for all to be heard, take minutes, and 2. Dentistry Today. 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INDEX

Page numbers followed by ‘‘f’’ indicate figures; page numbers followed by ‘‘t’’ indicate tables.

A ADA. See American Dental American Dental Association Association (ADA) (ADA), 4, 87, 88, 113, AAE. See Association of Adaptive immunity, cells of 709, 748, 814, 1476 Endodontists (AAE) regulatory T lymphocytes, 351f American Endodontic Society, 1066 Abscess theory, 313, 506 subpopulations of T cells, 349t American National Standards Abutment tooth selection T cells and Naı¨ve CD4 T cells, Institute (ANSI), 814, 1036 technique, 1461 349–350 American Society of Access cavity, 894, 1127 T cytotoxic and B cells, Anesthesiologists (ASA), magnified view, 1098f 348–357 749 preparation, 877 Th3 cells, 349 categories and classifications, effect on structural integrity, Treg and Tr1 cells, 350 755–758 1033 A- fibers, 664 Anaerobic bacteriologic finding pulp chamber, 895 Adjunctive procedures, root canal techniques, 24 increased susceptibility to treatment, 113 Anatomic apex, 25 fracture, 918f Adjunctive therapy, 1350 Anesthetics and drugs, 786t obtaining SLA, 894 Adrenal suppression and long-term ANSI. See American National obtain uniform contact of file, steroid use, 770 Standards Institute 861 Adverse effects, drugs combination (ANSI) penetration through occlusal coumadin with quinolone, 784 Anterior cingulated cortex (ACC), surface, 896 digoxin–tetracycline, 784 398 sequence of steps, 927f macrolide–quinolone Antibacterial/microbial activity, unroofing dentin, 886 combination, 784 992 types of designs, 943 methotrexate with penicillin, 780 CHX, 1005–1010 varying according to degree of AEL. See Electronic apex locator EDTA, citric acid and other curvature, 887 (AEL) acids, 990–1015 Actinomyces, 258 AH 26 (thermaseal), 1071–1072 hydrogen peroxide, 1002 Actinomyces israelii,500 fluid conductance model, 1071f NaOCl, 994–997 Activated pathways during ALARA, 574, 584 Antibiotic prophylaxis regimens for inflammatory response, Allergy to materials used in patients with total joint 353f endodontic therapy, 770, replacement, 768f Acute inflammation, 345, 473–474 771f Antibiotics, 775 histologic evidence, Alveolar bone, 13 and analgesics, 772–776 inflammation in Amalgam and effects on oral underlying pulp, 473f perforation repair, 1156 contraceptives, 751 polymorphonuclear leukocytes, Ameloblastoma, 616f Anticoagulant therapy and early inflammation, 474f desmoplastic type, 617f bleeding disorders Acute inflammatory process, 381 growth/removal, 101f discontinuing aspirin prior to Acute rhinosinusitis, 628. See also American Association of proposed surgery, 760 Chronic rhinosinusitis; Endodontists (AAE), 86, modification of anticoagulant Subacute rhinosinusitis 93, 103, 266, 660 therapy, 760

1513 1514 / Index

Antigen-presenting cells (APCs), 497 Apical patency/preparation, 28–29 radiographic Antimicrobial peptides, Apical perforation management, aspects of, 605 -defensins, 360 1133 and histological appearance Anxiety/fear problem, endodontics Apical periodontitis, 2, 311, 603, of, 534f management, 741 604, 887, 1092 reversal/regression in healing of, recognition, 748–749 causage, 936 1189f APCs. See Antigen-presenting cells cholesterol and, 324 success and failure of endodontic (APCs) crystals and cystic condition treatment, 617–618 APEXIT, 1070 of, 325f teeth treated with associated, 1198 Apical cholesteatoma, 325 clinical relevance of cysts, dynamics of healing, 1191 Apical constriction, 25, 930 322–324 functional teeth, 1191 lost, 930 condensing at distal root, 603f healed teeth, 1198–1199 Apical dental cyst, 584f cone beam CT, 606f healing in progress, 1191 Apical diagnosis criteria for assessing healing of, teeth treated without associated acute apical abscess, 529 919 dynamics of developing acute/chronic apical abscess, 529 cystic, 311f disease, 1184–1187 apical scar, 529 diagnoses, 597 functional teeth, 1184 asymptomatic apical echographic examinations, 598 healed teeth, 1191 periodontitis, 529 endodontic orthograde Apical scar, progressive cellulitis, 529 treatment, 597 development of, 1164 condensing osteitis, 529 etiology of refractory, after Apical sizes and preparation normal periapical tissues, 529 treatment, 1901–1903 diameter of, 886 prognosis and informed consent, giant cell granuloma mimicking, larger sizes, 944 530–531 614f measured diameters and symptomatic apical healing of, 607, 607f suggested size for, 932t periodontitis, 529 lesions, 318f, 321f pre- and postoperative canal Apical foramen, 25, 640 prevalence of cysts in post diameters, 933f Apical lamina dura treatment, 324t Apical surgery, 324, 337 resorption/remodeling of, 602, microbial etiology of refractory, follow-up studies reporting on 602f 1192 outcome, 1212t surgical endodontic, 602 molar with canal in mesiobuccal laser in endodontics, 868 Apical leakage, 1068 root unfilled and with, outcome assessment of multi- delayed filling and, 1098, 1079f 605f rooted tooth after, 1173f and lasers, 1073 more frequent, 930 potential for healing and retained mean leakage values of sealers, origin of cyst epithelium, 344 function after, 1201 1071f persistence or recurrence of, 1193 dynamics of healing, 1191 microleakage and its evaluation, per-treatment variables functional teeth, 1191 1068–1069 apical enlargement, 1201 healed teeth, 1199–1192 smear layer and, 1073 bacterial culture before root healing in progress, 1191 Apical neurovascular damage, filling, 1197 recurrence of disease, 1211f consequences complications, 1209 Apical surgery, factors influencing prevention of pulp space flare-up during treatment, healing after, 1210 infection, treatment, 1198 post-treatment variable 1343–1344 length of canal preparation dynamics of resorption, 1211 pulp canal obliteration, 1343 and filling, 1195–1199 endodontic treatment, multinucleated osteoclasts, materials and techniques, 1207 outcome, 1222–1224 appearance of, 1343, number of treatment sessions, potential for healing and 1343f 1198 function after pulp necrosis, 1348 post-treatment variables replantation, 1119–1121 root canal disappearance, restoration, 1209–1211 results of biopsy, 1209 placement of thick prevalence of pretreatment variables calcium hydroxide, 1345, radicular cysts, 312t age, gender, and systemic 1345f in 35–45 year-olds, 622f health of patient, 1212 Index / 1515

apparent quality of previous previous perforation (in Avulsed tooth root filling, 1195 re-treatment), 1195 open/closed apex, 1339–1152 clinical signs and symptoms, pulp vitality or necrosis (in dry time, 1356 1202 initial treatment), 1194 replant, 1357 restoration, 1213 size of radiolucency, 1202 size of radiolucency, 1202 systemic health, 1201–1205 supporting bone loss, 1202 tooth location, 1201 B tooth location, 1201–1204 Apicalterminus/cleaning, apical second-time surgery, patency, 25–28 Bacteria pretreatment variables, Apical transportation, managing coccal forms of, 225f 1202–1207 Type I transportation, 1124 cultured/identified from root antibiotics, 1214 Type II transportation, canals of teeth with apical barriers and bone grafting 1124–1125 radiolucencies, 227t substances, 1209 clinical steps for, 1126f in dentin repair, 224f complications, 1209 MTA as barrier for choice of, influencing the outcome, hemostasis, 1214 1133–1135 242–243 laser irradiation, 1209 Type III transportation, 1125 persistence after intracanal level of apical resection and Apical true cysts, 313 disinfection procedures, degree of beveling, 1204 Apicoectomy. See Root-end 242t magnification and resections intracanal disinfection illumination, 1208 Applications of LDF, dentistry procedures, 241 operator’s skill, 1209 clinical dentistry, 551 invasion of pulp cavity, 225 presence or absence of dental trauma, 551 one visit versus two visits, 240–241 root-end filling, 1214 Appropriateness, Care and Quality post-instrumentation/ quality and depth of root-end Assurance Guidelines post-medication/ filling, 1205 AAE, 88 post-obturation samples, retrograde root canal Arachidonic acid, prostaglandins/ 240–241 re-treatment, 1208 leukotrienes, 395 Bacterial biofilms, 268–273 root-end cavity design, 1205 Armamentarium, clinical, 885 characteristics, 270 root-end filling material, accessory instruments, 895–896 communication/exchange genetic 1214–1215 Stropko Irrigator, 885–896 materials/acquiring new surgical and orthograde burs, 888 traits, 271, 271f treatment, 1208 examples, 890f criteria, 268 Apical surgery, persistent infection rotary instruments, 885 dentistry, 277–278 after, 1203–1204 Arrhythmias and cardiac development, 271 healing after pacemakers, 761 co-aggregation/co-adhesion, endodontic treatment, 1201 Arteriovenous anastomosis (AVA), 273f nonsurgical treatment, 1201 131 factors influencing initial pretreatment variables and ‘‘U’’-turn loops blood flow, bacteria–substrate age and gender of patient, regulation of, 132, 133f interaction, 272f 1201–1204 Association of Endodontists stages, 273f apparent quality of previous (AAE), 809 nutrient trapping/establishment root filling (in re- guidelines of, 56 of metabolic treatment), 1202 Assorted gutta-percha points, cooperativity, 270 clinical signs and symptoms, 1022f organized internal 1202 Asthma, 763 compartmentalization, elapsed time after previous Atherosclerosis, 324 270–271 treatment (in re- high level of cholesterol, 324 protection from environmental treatment), 1195 Automatic Exposure threats, 270 periodontal support, Compensation (AEC), resistance of microbes, 1194–1195 573, 586 antimicrobials, 281–3, presence/absence, Autotransplantation of human 273–274 radiolucency, 1205 teeth, 31 ultrastructure, 277–278, 269f 1516 / Index

Bacterial elimination in periapical Bacterial plaque, 318f Calcitonin gene-related peptide- lesions Bacteriostatic, 995 immunoreactive apical periodontitis, pain, Bacteroides melaninogenicus, 237 (CGRP-IR), 138f 501–502 BBHI-2. See Brief Battery for immunohistochemical staining of SRIF, 501–502 Health Improvement nerve fibers in rat dental athymic animals, studies in, (BBHI) pulp, 138f 503–504 B-cell antigen receptor (BCRs), 348 nerve fibers, 138f, 139f bacteria in periapical lesions, 499 Behavioral factors, pain behaviors, Calcium hydroxide, 992–912, extraradicular infection, 499 403 1067–1069 B cells/plasma cells/ Benzodiazepine for perforation repair, 1129 immunoglobulin and all drugs, 783t periapical repair following production Biofilm, 999 application of, 1968f antigen-presenting cells Biomaterial-centered infection Calcium hydroxide disinfection, 24 (APCs), 497 (BCI), 285–286 Calcium phosphate cement (CPC), bone-resorbing cytokines, BioPure. See MTAD 1066–1067 cellular sources, 503–510 Bisphosphonate-associated Calcium sulfate bone resorption in periapical osteonecrosis of jaws, 766 as perforation barrier material, lesions, 502–503 Bisphosponates, 967 1142 NSAIDs, 502 Bleaching of discolored dentin/ Campylobacter gracilis, 237 cells/immunoglobulins/ enamel, causes, 70 Campylobacter rectus, 237 cytokines, periapical Bleeding Canal(s) lesions, 495 increased risk of, 755 accessory, 154 complement activation (chain Blood flow rate, 133f curvature, observing reaction), 494 ‘‘Blunderbuss’’ canal, 27 radiographically, 886 diapedesis, 494 BMS. See Burning mouth managing blocked, lubrication, equilibrium, bacteria and host, syndrome (BMS) 1133 500–501 Bone loss, fenestration type of, 679, shaping procedures, 907 ‘‘phoenix abscess,’’ 500 679f effect of, anatomy, 961 flare-ups in periapical lesions, Bone marrow and solid organ surface modification, 970–971 immunobiological view, transplantation appearance after shaping, 933f 500–501 hematopoietic stem cell irrigation dynamics, 967 immunobiological concept of transplantation, 766–767 photodynamic therapy, 970 periapical lesions, Bone resorption, mechanisms of smear layer removal, 966t evolution, 495–496 mediators promote or inhibit, 364t surfaces, 969 local activation, nociceptors in regulations of osteoclast systems to prepare canal, 966t apical granuloma, 501f differentiation and key in tooth, identification of, 581 macrophage presence, kinetics cytokines, 365f transportation, 961 of, 499 Brief Battery for Health types macrophages in periapical Improvement (BBHI), 406 Sert and Bayirli’s, 154f granuloma, 511–512, 505f Brynolf’s interpretation, 26f Vertucci classification, 154f, 155f osteoclast activation Buccal cusp, occlusal view, 1433f variations osteoprotegerin ligand, Bull-like teeth. See Taurodontism factors contributing to, functions, 504 Burning mouth syndrome (BMS), 151–152t PMNs, 494 453, 454–455 in number of, 153 protective function of T Canal, preparation lymphocytes in periapical anticurvature filing, 939 granuloma C balanced force, 940–946 T lymphocytes, role of, description, 943 508–509, 505f Calciobiotic root canal sealer, 1035 principles of the, 965f T lymphocytes, periapical Calcitonin gene-related peptide cross sections before and after granuloma, 497–498 (CGRP), 395, 461 preparation, 958f Bacterial factors, flare-ups, and substance P (SP receptors), crown-down pressureless, 942–943 707–708 120, 120f sequence of instruments in, 960f Index / 1517

devices for powered, 951 Cavit, 1042 CC chemokines, 352 motors for rotary endodontic perforation repair, common chemokines, receptors instrumentation, 951–953 1128 and cells, 352t sonic canal instrumentation, Cavity CXC chemokines, 352 954 cleansing, 481 Children, treatment for ultrasonic canal crown preparation, 480 educational curricula and instrumentation, 953–954 Cavity preparation attitudes of pediatric double flare, 943 access, 886–889 dentists, 1423–1425 handpieces with continuous improper angulations and, 882f nonvital pulp therapy, 1417–1418 rotation, 961 standard hand instruments, 884 pulpal pathosis in children, instruments coronal access, 877 diagnosis of, 1403 cutting blade design, 961 CBVCT. See Cone-Beam Chlorhexidine digluconate (CHX), instrument shaft design, 961 Computed Tomography 1002–1006, 1010–1011 k-files, 963 (CBCT) Choice of practice, operations prevalence of instruments Cellulose granuloma, 334 management, 1474 fracture, studies on, 983 paper-point granuloma affecting associate-employee/independent relationship of torque during and root-canal-treated human contractor, 1478 fracture load, 953f tooth, 335f Internal Revenue Service root canal Cemental apposition, healing, 62f (IRS) guidelines, 1478 aseptic techniques and Cementodentinal junction, 26 part-time schemes, disinfectant, 1057, 1058f Cemento-enamel junction (CEJ), combination, 1478 filling/vertical root fracture, 638, 883–884 hybrid, 1478 959f centered pulp chamber, 891f new practice, 1477–1478 preparation, 959f Cements and pastes (filling practice models, 1476–1477 sequential mechanical materials) ADA, 1476–1477 enlargement, 960f calcium hydroxide, 1067–1068 DTA, proposed model, 1477 standardized, 936–937 calcium phosphate cement, service factory model, 1477 step-back (telescopic technique), 1066–1067 service theaters, 1477 937 dentin chip apical obturation, super-norm model/ sequence of instruments, 938f 1067–1068 Armstrong’s service step-down, 945–946 N2/Sargenti paste, 1066 theater approach, 1477 procedure itself, 938f resin cements, 1067 setting goals, 1476 purpose, 945 Central incisors fluorosis, treated by practice goals, 1476–1477 shaping coronal aspect, 938f, external bleaching, 1385 strategic planning, 1475–1476 945 Central mechanisms, 384 vision and mission statements, ultrasonic inserts fracturing, 955f alternative hypotheses, 385f 1475 Canal Finder system, 951 sensitization, 384 ‘‘22 Keys to Creating a Cancer chemotherapy and Central nervous system (CNS), 393 Meaningful Workplace,’’ radiation therapy, definition, 764 1475 765–767 depressants, 743t mission, definitions, 1475 Ca(OH)2. See Calcium hydroxide Central trigeminal pain system, PEST analysis, 1476 Capillary loops, 132f organization and function SWOT analysis, 1476t Capset. See Calcium sulfate of, 379 Cholesterol, 324 Carbon fiber-reinforced (CFR) Cervical root resorption, 602f, 603f apical periodontitis, 324–325 epoxy resin post, progress, apical, 603f crystals, accumulation of, 325 1453–1454, 1453f CGRP. See Calcitonin gene-related cyclopentanoperhydrophe- Caries removal, vital pulp therapy peptide (CGRP) nanthrine, 324f caries affected dentin, 1318 Charge-Coupled Device (CCD), in disease, 324 rubber dam isolation, 1391 573, 577, 581 Teflon cage model, 325 Catonella morbi, 237 Chemokines tissue reaction to, 325, 326f, 327f Causalgic pains adhesion molecules, tissue Chronic apical periodontitis, 1099 sympathetically maintained distribution and ligands, Chronic inflammation, 345, 474–475 pains (SMPs), 443–444 353t granuloma, 475 1518 / Index

pulpal abscess, 475 Cone-Beam Computed Tomography Coronal tooth preparation, 1458, beneath deep cavity (CBCT), 573 1458f preparation, 486f demonstrating apical dental cyst, Corrective surgery Chronic obstructive pulmonary 600f bicuspidization, definition, 1281 disease (COPD), 752 Cone positioning, endodontic curved periodontal probe, 1279f Chronic rhinosinusitis, 628, 634 radiography, 559 definition, 1274 Claims against, endodontists, 87t horizontal cone angulations. See hemisection, 1279–1281 Clark’s rule of horizontal Horizontal cone completed on mandibular angulation, 560, 561f, 929. angulations second molar with See also Ingle’s MBD rule long cone, 557 fracture, 1299f Cleaning/disinfecting, root canal short cone, 557 periodontal regenerative system (laser), 860–861 teeth, 559f procedures/ Cleaning/shaping, instruments, Congestive heart failure, 761–762 contraindications, 1281 813–838 New York Heart Association’s periradicular repair, 1295–1296 basics. See Endodontic classification system, 762f replantation, intentional, instruments Coronal access cavity preparation, 1281–1284 Nickel-Titanium. See Ni-Ti 877 root amputation, 1277–1279 endodontic instruments Coronal disassembly devices nonsurgical root canal rotary. See Rotary instruments active instruments, 1096–1097, therapy, 1277 Clinical examination, endodontics, 1097f root canal therapy, completed, 524 grasping instruments, 1096 1298f vital signs, 524 percussive instruments, 1096 traumatic root fracture repair, blood pressure/temperature/ Coronal evaluation 1277 cancer screen, 524–525 intraorifice barrier, 1042 Cracked tooth, 660 coronal evaluation, 525 Coronal leakage, 645, 1091 Crown fractures extra/intra oral examination, barrier, 645 complicated, 1330–1331 525 closure materials and variations histologic appearance, pulp Clinical guidelines, preoperative, 886 in, 1076, 1077f within 24 hours of assessing complicating factors, 886 evaluation methods, 1056 traumatic exposure, 1353f assessing occlusal/external root leak proof amalgam, 1078f concomitant attachment form, 886 Coronal leakage and prognosis for damage, 1331 determining point of penetration, healing, 1091–1093 restorative treatment plan, 886 armamentaria and missed canals, 1331–1332 radiographic assessment and 1097–1100 root measurement, 886 coronal disassembly, 1095 horizontal, 1304f, 1339 CMOS-APS, 573, 577–578 coronal disassembly devices. See treatment, 1341 CNS. See Central nervous system Coronal disassembly time between accident/treatment, (CNS) devices 1331 Codes of Ethics, ADA, 88, 102 factors influencing restorative tooth development, stage of Collagen, 129–130 removal, 1095–1096 ‘‘blunderbuss,’’ 1331 as perforation barrier material, non-surgical versus surgical treatment, 1331 1130 retreatment, 1095 vital pulp therapy, 1313 Color power Doppler (CPD), 592 technology of retreatment, C-shaped canals, 915 application to echography, 593 1094–1095 Cuspal fracture odontalgia confirming information, 593 temporary coronal restorations, identification problem, 663 picture representing the echo, 608f 1093–1094 Cyclopentanoperhydrophenanthr- Complementary Metal Oxide Coronal pulp, 131f ine, 324f Semiconductor (CMOS), Coronal restorations, temporary, Cyst, 311, 321 573, 577, 580f 1093–1094 bay cyst, 313 Complement cascade, 354f Coronal restorative nonsurgical root canal therapy, 322 Composite resins, 1042 procedures, 71 radicular cyst, 323f Computed Dental Radiography root canal space/coronal access apical pocket cysts, 315f, 316 (CDR), 573, 586 openings, involvement, 71 apical true cysts, 313 Index / 1519

Cystic apical periodontitis, 311f Dental materials, 482 distribution, 137–139 cysts and periapical healing, Dental pulp, 37, 119, 119f, 126. See function, 139–141 321–322 also Vital dental pulp neuropeptides, 137 diagnosis of periapical cysts, chronology of discoveries neurophysiology, 142–143 309–310 histology, 37t–38t receptors, 141–142 foreign bodies, 328–332 pulpodentinal histology, 37 structures and functions genesis of pocket cysts, 316–321 layers in, 126f arteriovenous anastomosis and genesis of true cysts, 313–316 photos, 39f ‘‘U’’-turn loops, 131–132, oral pulse granuloma, 332–334 sensory and sympathetic nerves 132f periapical cysts to, 137f cellular structures, 127 histopathology of, 312–313 Dental Trade Alliance (DTA), 1477 dental pulp, 125–126 incidence of, 309 Dental trauma, treatment methods dental–pulp complex, 121 Cystic lesions, 320–321 Cvek partial pulpotomy, 1335f dentin permeability, 121–123 ciliated columnar epithelial cells full pulpotomy, 1336 dentin sensitivity, 124–125 (CEP) lining of, 312f partial pulpotomy, 1333 dentin structure, 121 Cyst luminal wall, 317f ‘‘Cvek pulpotomy,’’ 1333 extracellular matrix, 129 Cyst management, 60f pulp capping, 1333 fibers, 129–130 Cyst versus granulomas, 597 pulpectomy, 1336 fibroblast, 127 differential diagnosis, 595 technique, 1333–1337 ground substance, 130 Cytokines Dental treatment immunocompetent cells, 129 origin and actions of, 356–357t level of compliance, 750 interstitial fluid, 125–127 roles of cytokines in modification of, 749 low-compliance system theory, periradicular bone need for modification 134–135 resorption, 366 MD-RAM, 752, 753f lymph vessels, 136 systemic effects of, 358 physical examination prior to, 751 odontoblasts, 127–129 previous dental, 751 pulpal microvasculatures, recommendations for 130–131 D modification of, 752 pulp reaction to permeating stress of, 751 substances, 123–124 Decayed-missing-filled (DMF), 10 Dentin, 121 regulation of pulpal blood Decimated dentition, 15f permeability, 121f flow, 132–134 Deep caries, treatment of, and pulp, balance between, 123f stealing theory, 134 1403–1405 and pulp complex, structure of, transcapillary fluid flow, 135 pulpotomy treatment and 118 Dentin thickness, after endodontic indirect pulp therapy, sensitivity, theories of, 124 treatment 1403–1405 tubules, 121 post/core, type of success rate of, studies, Dentinal hypersensitivity, 386 prefabricated, 1452–1457 1404–1405 Dentinal tubules Dentistry, initial suggestions, Definitive restoration, type of exposed, as communication 549–550 coronal tooth preparation, 1458 pathways between pulp Design aesthetics, operations DEJ. See Dentin-enamel junction and periodontal ligament, management, 1484 (DEJ) 638, 608f branding, 1484–1485 Dens evaginatus, 165, 201 scanning electron micrograph of assimilation, program in Dens invaginatus, 165 open, 639 action, 1489–1490 type 1, 162 Dentin chip apical obturation, 1067 brand–customer relationship, type 2, 162 root canal plug after 3 months, 1491 type 3, 160f, 161f, 158–165 1068f customer relationship, 1491 radicular-form of, 165f Dentin-enamel junction (DEJ), 481 developing culture of excellence, Dental claims, frequency, 87t Dentin–pulp complex, 118 basic steps, 1494 Dental implants embryology, 118–121 enabling successful practice, on endodontics, effects of, 108 nerves in pulp 1484 provisional restorations, classification of nerves, increased concern, case, 1296–1306 136–137, 137t 1484–1485 1520 / Index

office personality, 1488 physical examination electronic thermography, 543 strategic development, cranial nerve examination, Hughes Probeye 4300 thermal 1489–1490 411, 411t video system, 543 strategic development/ inspection, 411, 423t transillumination, 540 foundation building/ local pathosis of extracranial fiberoptic illumination, 541 implementation, structures, 413t ultraviolet light, 544 1489–1490 myofascial TrP examination, visual oral examination/review of technology to operationalize, 411 systems. See Visual oral use of, 1487–1488 psychogenic pain, 413 examination, diagnostic touchpoint overview, 1491–1494 Diagnostician, requirements testing understanding, 1494–1495 curiosity, 521 Diaket, 1070 creating a web site/stationary/ interest, 520, 521 Dialister invisus, 237 brochure intuition, 521 Dialister pneumosintes, 237 web site, starting pointers, 1506 knowledge, 521 Differential scanning calorimetry customer satisfaction index, patience, 521 (DSC), 802–807, 804f, 1486, 1486f Diagnostic studies, 412, 412t 805f, 827 employee motivation and Diagnostic testing Digital Imaging and morale, 1488–1489 anesthetic test, 542 Communication in attitudes/retention, 1492 infiltration, 542 Medicine (DICOM), 573, brand-driven behaviors, 1489 dyes, 542–543 576, 579 goals, branding strategy, 1486 caries indicator solutions, 543f Digital intraoral radiography, HIPAA, 1492 electric pulp testing. See Electric endodontic roots of, 574 learning organization, existence, pulp test (EPT) Direct pulp cap, 1405 1489 magnification, 542 treatment recommendations, NHII, 1487 mobility, 539 1320–1322 office design, 1483t Miller Index, 539 vital pulp therapy patient satisfaction surveys, palpation, 539–540 of mandibular left molar, 1495–1496 crown of tooth with crack radiographic/clinical TQM, 1496 located transilluminator, sequence, 1322 ‘‘quality in fact’’/’’quality in 553f one-step pulp capping, 1322 kind,’’ 1495 toris mandibularis, 540 Discoloration, 11 understanding satisfaction, 1495 PDL injection, 542 Doctor-Patient Relationship Diabetes, 762–763 percussion, 539 (DPR), 86 Diagnosis periodontal probing, 541 Dog pulp, 118f case history, 407 double-ended instruments, 541 Doppler technique, 134 classification, 407 Glickman classification Drainage through coronal access clinical classification of system, 541 opening, 706 craniofacial pain, 407t methylene blue dye, 541f complex diagnoses, 707 extracranial/intracranial vertical root fracture (VRF), 541 instrumentation, 707 pathema, 408 pulpal blood flow, measurement, magnification/illumination, history 544 enhanced, 707 chronic paroxysmal system B hot pulp test tip, 537 trephination, 707 hemicrania (CPH), 409 test cavity, 541–542 Drug administration, comparison general inspection, 410 thermal tests, 533–537 of routes, 747t myofascial TrP pain, 409 carbon dioxide snow, 535 Drug–drug interactions past medical, 410 cold response, 534 antibiotics and effects on oral PHN, 408 false negative, definition, 534 contraceptives, 781 social, 410 solid CO2, applied on tooth/ effect of oral contraceptives, 781 temporal patterns, 408 tank, 536f effects of combination of drugs, operant pain (pain behavior) warm/cold, 535–538 781 somatization/malingering/ warm thermal technique, 537 patient’s response to, 780 munchausen syndrome, tooth surface temperatures, problems with higher levels of 414 measurement, 543–544 combination of drugs, 782 Index / 1521

serious drug reactions with Electric pulp test (EPT), 630 ethical basis for standard of macrolides, 782 Analytic Technology pulp tester, care, 88 unexpected effects of new drugs, 538, 538f moral behavior, 88 781 Electrocardiogram (EKG), 538 factors deciding retreatment, 1100 Drug interactions patient placing finger lightly on fractured premolar restoration, change in reactions, 781 metal part of the probe 12f by combination of drugs, 781 handle, 538f frequency of claims, 86–87 increased/decreased effects, Electric pulp tester, 534, 547, 713 future of, 74 781 Electronic apex locator (AEL) historical stalwarts, 73–74 with food and herbals, decrease/ accuracy, 844 informed consent, 87–94 increase effects of dual-frequency electronic apex AAE, 93 Ginkgo biloba, 787 locators, 851–852 definition, 92 Kava, 787 high/low frequency apex objective standard, 92 Khat, 787 locators, 851 length determination Licorice, 788 multiple-frequency electronic controversies in, orange juice, 788 apex locators, 852–853 1139–1140 other drugs, 787 resistance-based electronic malpractice, common elements, Drug interactions and laboratory apex locators, 849–850 86t tests voltage gradient apex locators, miracle cures/pastes/mystery, 73 with food and herbals, 787–788 851 anesthetics, 74 drugs prescribed by dentist generations, first to fifth, 849 irrigants, 73 that may interact with parameters for use, 853 medicaments, 73 herbal medicines, 802t Electrosurgery/electrofulguration, obturation materials/ lab tests of potential importance 1412–1414 techniques, 74 in endodontics, 788–789 comparing studies, 1413–1417 surgical materials/instruments/ Drugs, banned, 781 Emergency surgical procedures techniques, 74 Drugs prescribed by dentists radiographic interpretation, 1285 non-surgical treatment, root interact with warfarin Emphysema, 1146 canal systems, 48–53 anticoagulant, 787f radiograph of lower left canine, periapical origin DSC. See Differential scanning 1147f differential diagnosis/ calorimetry (DSC) swollen tissues, 1146, 1147f treatment, oral pain in DSC heating (lower)/cooling Employee Retirement Income pulp, 43–46 (upper) curves, 803f, 804f, Security Act (ERISA), etiology/diagnosis/prevention/ 805f 1504 treatment, pulp disease, D-speed film radiographs versus Enamel knot, 119 40–43 TACT, 582–583 Endodontics, 3–4, 12f morphology/physiology/ DTA. See Dental Trade Alliance access human dental pulp, (DTA) clinical methods, 153 pathology/periapical laboratory methods, 153 tissues, 37–40 anxiety/fear problem periapical pathosis, surgical E management, 738 removal, 53–66 recognition, 737–738 record keeping, 98–100 Echography, 309 regulation, 739–740 SOAP format, 98 The Economics of Endodontics,4 areas, 37 referrals, 100–103 Edentulism, 10 chronology, developments, four general categories, 102 Educational curricula and attitudes 51t–52t subsequent radiograph, 100 of pediatric dentists, clinical symptoms and lesions of, scopes, 65 1423–1425 origin, 1097f standard of care, 88–91 caries on primary incisors, 1424f defined, 1 controversy, 89 EEO. See Equal employment definition, 37 definition, 88 opportunity (EEO) DPR. See Doctor-Patient endodontic instrument, 89f Eikenella corrodens, 237 Relationship (DPR) informed/uninformed, Electric foramen locator, 929 ethics/morals, 86–88 consent, 91 1522 / Index

instrument breakage, 89 hard tissue apical barrier, culture, advantages/ legal claims, role of, 88 1337–1338 limitations, 234–236, 230t paresthesia, 91 internal root resorption, 1352–1353 endodontic flare-ups, 266 root canal filling, 89 luxation injury, 1347–1348 specific bacteria, endodontic vital pulp therapy, 46–48 pulp revascularization, 1338–1339 symptoms/associations, Endodontic abscesses/cellulitis, mature teeth, 1339 267–269 treatment of, 692 root filling visit, 1351 intracanal disinfection acrylic stint in place for treatment. See also Dental procedures, 241 decompression, 699f trauma, treatment microbes, association, 224–227 antibiotics, 692–698 methods outcome, bacterial influence, in endodontics, 693–695 established external root 241–243 aspirate from abscess/cellulitis, resoption, 1345–1347 primary intraradicular 693f nonvital pulps. See Nonvital infections, 236–238 biopsy from window consistent pulps treatment Endodontic disease, primary with radicular cyst, 699f root fracture complications. endodontic therapy, 626 capillary/penrose/rubber dam, See Root fracture in mandibular first molar with drain, 693f complications, treatment necrotic pulp, 648f collection of a microbial sample, of osseous repair, following trauma, 696 vital pulp therapy. See Vital pulp 648f conditions not requiring, therapy, traumatic dental Endodontic endosseous implants, adjunctive antibiotics, injuries 69–70 694t Endodontic disease, microbiology Endodontic examination cortical trephination, 696–697, actinomyces, 262–263 apical diagnosis. See Apical 699f bacterial biofilms, 268–269 diagnosis decompression, aspiration and adoption of resistance, clinical examination. See Clinical irrigation, 697–701 phenotype, 276–277 examination, endodontics nasogastric tubing in cyst for BCI. See Biomaterial-centered diagnostician, requirements of, decompression., 700f infection (BCI) 520 drain sutured in place, 692f characteristics, 270 history healed surgical window, 699f communicate, exchange chief complaint, 523 incision for drainage, 692–693 genetic materials/acquire medical history form, 521, 522t needle aspiration, 692–694 new traits, 271 present dental illness, 523–525 prophylactic antibiotics for in dentistry, 277–278 pulpal diagnosis, 526 medically compromised development, 271–273 Endodontic failure, 309, 1296, patients endodontic, 278–279 1296f AHA, 695 extracellular polymeric matrix, cause, 1125 surgical window into cyst, 699f resistance, 276 Endodontic flare-ups Endodontically treated teeth extraradicular microbial, age of patient, 701 risks associated with post- 283–284 anatomic location, 701–702 retained restorations of, growth rate/nutrient anxiety, 702 1200 availability, resistance, 276 gender, 701 Endodontic biofilms, 278–279 intracanal microbial, 279–283 glossary, endodontic terms, 700 Endodontic considerations in microbes to antimicrobials, inter-appointment pain, causes dental trauma resistance, 273–275 of, 702 adjunctive therapy, 1350 organized internal mechanical/chemical injuries, apical neurovascular damage, compartmentalization, 702 effects, 1343–1345 270–271 obturation, 704 avulsed tooth, 1348–1352 periapical microbial, 284–285 preoperative history, tooth, 702 crown fracture, 1330–1332 protection from environmental pulp/periapical status, 702 dental trauma, unique aspects, threats, 270 re-treatment cases, 703 1330 ultrastructure, 269–270 swelling associated with flare- endodontic essentials/treatment. diagnostic techniques, up following revision, 703f See Endodontics, essentials microbiological, 227–228 systemic conditions, 701 Index / 1523

treatment of teeth, vital/non-vital fracture mechanisms, 943 diabetes, 762–763 pulps, 702–703 gates glidden modification, 823 heart murmurs and valvular treatment visits, number of, 702 hand instrument conclusions, 823 disease, 757–760 working length, 703–704 hedstrom files, retraction, hypertension, 754–757 Endodontic flare-ups, treatment of 821–822 ischemic heart disease, diagnosis and definitive H-style file modification, 822 756–767 treatment, 705–706 Quantec ‘files,’ 823 vasoconstrictor use in patients Endodontic implants, 1298, 1299f reamers, 816 with cardiovascular Endodontic infections, 223–224 tip modification, 820–821 disease, 755–756 anachoresis, 225 H-style instruments, 821f central nervous system, 764–765 colonization, 223 U-file, 822 human immunodeficiency virus, control of cross-sectional view, 822f 768–769 host defense system, 992 lightspeed instrument, liver disease, 769 instrumentation and unusual, 822f medical consultations, 752 irrigation, 992 marketed names, 820–821 medical history and patient intracanal medicaments, 1009 Endodontic panacea. See Calcium interview, 749–750 permanent root filling, 992, hydroxide medications and allergies, 1003 Endodontic patient, medically 750–751 interaction and characteristics, complex, management of physical exam: vital signs, 751 1089f adrenal suppression and long- physical health status, 751–752 microorganisms, 238–240 term steroid use, 770 pregnancy, 768 archaea, 238 allergy to materials in previous dental treatment, 751 fungi, 238 endodontic therapy prosthetic joints and other virus, 238–240 antibiotics and analgesics, prosthetic devices, missed canals, finding, 1100 772–773 767–768 and MSDO, 631–635 intracanal medications, pulmonary disorders: asthma, pathogenicity, 224 cements, and filling COPD, and tuberculosis, polymicrobial interactions/ materials, 773–774 763–764 nutritional requirements, irrigating solutions, 773 relative stress of planned 225–226 latex, 772 procedure and behavioral pulpal/periapical pathoses, 224 local anesthetics, 770–772 considerations, 751 virulence factors, 245–249 assessing need for treatment renal disease and dialysis, 765 Endodontic instruments, 2, 89f, 814 modifications sickle cell anemia, 769 AAE, 814 multidimensional risk Endodontic–periodontal diseases, ADA, 814 assessment model 654, 654f ANSI, 814 (MD-RAM), 752–754 communication, main pathways, barbed broaches, 823–824, 823f bone marrow and solid organ 638 cutting blades, 814 transplantation diagnosis for treatment and endodontic instrument hematopoietic stem cell prognosis, 647 standardization transplantation, 766–767 primary endodontic disease, autoclaving, 814 solid organ transplantation, 767 647 K-style modification, 815–816 cancer chemotherapy and primary periodontal disease, unused instruments, condition radiation therapy, 647 of (comparisons), 815f 765–766 secondary periodontal files, 816–820 bisphosphonate-associated involvement, 647–650 competing brands for cutting osteonecrosis of jaws, 766 endodontic and periodontal, 638 ability, comparison, 817 cardiovascular disease in mandibular first molar, 655f instrument breakages, anticoagulant therapy and presence and prevalence of fungi, Sotokawa’s classification bleeding disorders, 761 643–644 of instrument damage, arrhythmias and cardiac role of bacteria, 641–644 819f pacemakers, 761 Endodontic–periodontal instrument fracture, cracks congestive heart failure, interrelationships and deformation, 820f 762–763 communication, 638 1524 / Index

apical foramen, 640 processing, 570 kerr pulp canal sealer EWT, 1069 dentinal tubules, 638 rapid-processing solutions, rationale for use of sealers, lateral and accessory canals, 570–571 1068–1069 638–640 short cone, 557 roth’s 801, 1069 contributing factors, 644 table-top developing, 571 SealApex, 1069–1070 coronal leakage, 645 traditional machines, 557 VITAPEX, 1070 developmental malformations, vertical angulation, 560 Endodontics mode, 878 646–647 working radiographs, 558–559 accessing through crown, inadequate endodontic Endodontic retreatment disadvantages, 878 treatment, 644 preoperative radiograph of non- areas in, use of lasers, 962–963 root perforations, 646 healing maxillary central existing restorations, advantages, traumatic injuries, 645–646 incisor, 1094f 878 dentin exposure, importance in special concerns in, 1090 Endodontic specialists, 3, 5f, 6f, 7f progression, 638 Endodontics, digital imaging for, Endodontic studies differential diagnosis, 647 573–574 acceptable, relevant procedures, primary endodontic disease, digital intraoral X-ray imaging 1178 647 options categories, 1171 with secondary periodontal digital radiography, 576–577 evidence-based practice, 1171 involvement, 647–650 using secondary capture of minimizing bias in studies, primary periodontal disease, analog film images, 1171 647 574–576 research design, 1170 secondary endodontic radiation dose, 583–587 confounding effects of different involvement, 650–653 working principles of digital variables, 1179–1181 prognosis, 654–656 systems considerations specific to, 1179 true combined diseases, advantages of digital X-ray treatment differences in studies 653–654 imaging, 579 on apical surgery, 1190 etiological factors, 641 conventional versus digital, variation in treatment bacteria, 641–643 581 procedures, 1175–1177 fungi, 643–644 detection of periapical lesions, Endodontic surgery viruses, 644 581–582 anatomical considerations, pulpal–periodontal detection of root canal 1235–1237 interrelationship, 640–641 anatomy, 582–583 anesthesia and hemostasis, Endodontic-periodontal lesion, digital subtraction 1237–1239 608f radiography, 583 adrenergic receptors in tissues, Endodontic procedures, evaluation of assessment of 1238 nonsurgical root canal length, 582 beta-adrenergic effect, 1239 confined to root canal, 930 examples of digital images objectives, 919 Endodontic radiography, 554 used in endodontics, osteotomy on mandibular application of radiography to 579–580 molar, 1238f endodontics, 554–556 solid-state systems, 577–578 periradicular surgery, 1244 limitations of radiographs, 556 storage phosphor detectors, vasoconstrictor, 1249 technology systems, 556–557 578–579 vasopressor agents, 1237 cone positioning, 559 Endodontics, essentials, 1348 corrective surgery. See diagnostic radiographs, 558 concussion/subluxation, 1347 Corrective surgery extraoral film placement, 570 extrusive/intrusive/lateral emergency procedures. See film, 557 luxation, 1347–1348 Emergency surgical horizontal angulation, 560 treatment, 1350–1351 procedures horizontal cone angulations. Endodontic sealers, 1068 flap designand soft tissue See Horizontal cone APEXIT, 1070 management. See Soft angulations bonding to gutta-percha and tissue management and intraoral film placement, dentin, 1072f flap design 557–558 calciobiotic root canal sealer, greater palatine foramen, long cone, 557 1069 opening of, 1235f Index / 1525

historical perspectives Endodontic therapy educational curricula and microsurgical endodontics, allergy to materials used in, 770, attitudes of pediatric 1233 771f dentists, 1423–1425 specific indications, 1234 anticipating the future, 29 electrosurgery/electrofulguration, horizontal/vertical sulcular case representation, 10–12 1412–1414 incisions, 1241, 1241f considerations, 16 ferric sulfate, 1259–1260 implant surgery. See Implant indications, 12–15 formocresol, 1406–1411 surgery oral conditions, 16–21 freeze-dried bone, 1412 indications/contraindications/ change glutaraldehyde, 1411–1412 classification attitudes, 4 lasers, 1414–1415 endodontic surgery, endodontics, 3–4 medical factors in determining if contemporary instrument design/ a primary tooth should be classification of, 1234 standardization, 2–3 saved palatal flap reflected and nomenclature, 1–2 contraindications, 1460–1461 sutured, 1244f endodontics, controversies mineral trioxide aggregate, 1030 periradicular surgery/treatment. apical patency and its nonvital pulp therapy for See Periradicular surgery, preparation, 28–29 children, 1417–1423 treatment planning apicalterminus and cleaning pulpotomy, 1406 rectangular flap to perform apical patency, 25–28 treatment of deep caries: indirect periapical surgery on postoperative pain, 23 pulp therapy, 1403–1405 maxillary central and single-appointment therapy, vital pulp therapy for children: lateral incisors, 1242f 21–23 direct pulp cap, resection, root-end. See Root- success versus failure, 23–25 1332–1333 end resections factors influencing post removal Endodontic therapy and mishap scar (arrow) in gingival tissues and heat transfer, management, retreatment resulting from use of 1136–1138 of non-healing, 1088 semilunar flap for future, as speciality, 4–10 air emphysema, 1146 periapical surgery, 1243f inadequate radiograph of blocks, ledges, and apical soft tissue lesion, 1250 mandibular first molar with transportations, 1122 submarginal flap at time of crown, screw post, 1115f techniques for managing apical suture placement, 1244f mishaps and serious transportations, 1123–1125 surgical outcomes. See Surgical complications of techniques for managing outcomes factors influencing post blocked canals, 1122–1123 tissue management removal and heat transfer, techniques for managing canal hard, curettage. See Hard 1135–1137 ledges, 1123 tissue management and thermal injury with use of carrier-based gutta-percha, 1141 curettage ultrasonics, 1135–1136 coronal leakage and prognosis soft, suturing/postoperative past/present, future prologue, for healing, 1091–1093 care. See Soft tissue 29–30 armamentaria and techniques management, suturing post insufficient, 1097f associated with missed and postoperative care; thermal injury with use of canals, 1097–1100 Soft tissue management ultrasonics, 1135–1136 coronal disassembly, 1095 and flap design transforming advances coronal disassembly devices. topical/local, hemostasis. See saliva, diagnostic/informative See Coronal disassembly Hemostasis, topical/local fluid, 30 devices triangular flap to perform tissue engineering, 30 factors influencing restorative periapical surgery tooth regeneration, 30–31 removal, 1095–1096 distobuccal root of maxillary Endodontic therapy, primary teeth non-surgical versus surgical molar, 1241f comparison of primary and retreatment, 1095 mandibular second premolar, permanent tooth technology of retreatment, 1241f anatomy, 1400–1402 1094–1095 Endodontic techniques diagnosis of pulpal pathosis in temporary coronal aspects of, 1198–1199 children, 1416 restorations, 1093–1094 1526 / Index

damage to neurovascular repair based on evidence, risks, 1090 anatomy: causes and 1129 special concerns in endodontic outcomes, 1141–1142 esthetics and perforation retreatment, 1090 diagnosis and management of repair, 1130 techniques for obturation control inferior alveolar nerve hemostatics for perforation when neurovascular injury, 1142–1143 repair, 1130 proximity exists, 1140 management of inferior location of perforation, thermoplasticized gutta-percha alveolar nerve injuries, 1127–1128 and effects of heat, 1143–1144 MTA for perforation repair, 1140–1141 fractured instrument removal, 1129 Endodontic treatment 1114–1115 perforation repair materials, aim and asymptomatic function, coronal and radicular access 1128 1165 for, 1116–1117 periodontal condition and consent, 530–531 creating a staging platform, perforation repair, ameloblastoma, 100f 1117 1129–1130 disinfecting agents factors influencing, 1136–1137 restorative materials in Ca(OH)2, 1009 removal using microtube perforation repair, 1131 CHX, 1002 system, 1120–1121 size of perforation, 1128 hydrogen peroxide, 1388 techniques for, 1122 techniques for perforation NaOCl, 997–1002 ultrasonic techniques for, repair, 1131–1135 and increased susceptibility 1117–1119 timing of perforation repair, fracture, 920f length determination 1125–1127 internal resorption, 601f controversies in treatment sequence for local contraindications, 48f endodontics, 1139–1140 perforation repair, 1130 non-surgical, 643f mishaps and serious vision and perforation repair, persistent disease after complications of 1130 re-treatment, 1174f endodontic therapy post removal, 1110 replacing pulp tissue, 921 factors influencing post factors influencing, 1110 re-treatment in conjunction with removal and heat transfer, mechanical devices, internal perforation 1136–1138 1112–1114 repair, 1196f thermal injury with use of techniques for, 1110–1112 role of radiograph, 574 ultrasonics, 1135–1136 post-treatment infection of root root-end management with NaOCl accident, 1145 canal system bonded composite resin, causes of NAOCL accident, disease factors, 1088–1089 1177f 1145 previous root canal treatment, success of, 573 management, 1145–1146 1089 Endodontic treatment failure, prevention, 1146 prevention of obturation microbes, 257–258 obturation and irrigation mishaps, 1144–1145 Endodontic treatment outcome, mishaps, 1137–1138 removal of obturation materials, 1173 anatomic and imaging 1100 ambiguity of outcome definition, characteristics of inferior gutta-percha, 1131, 1162–1165 alveolar canal, 1138–1139 1138–1389. See also consequences of using terms anatomic and imaging Gutta-percha (filling ‘‘success’’ and ‘‘failure,’’ characteristics of material), removal of 1163–1165 maxillary sinus, 1138 microtube removal options, lenient definition of ‘‘success,’’ importance of accurate 1105–1107 1163 radiographic imaging, 1138 paste removal, 1108–1110 outcome definition as perforation and prognosis for Resilon, 1103 ‘‘uncertain,’’ healing, 1125 silver points, 1065 ‘‘questionable,’’ barrier materials for perforation risks versus benefits, 1089 ‘‘doubtful,’’ or repair, 1130–1131 benefits, 1089–1090 ‘‘improved,’’ 1163 clinical considerations patient considerations, strict definition of ‘‘success,’’ influencing perforation 1090–1091 1163 Index / 1527 antibacterial efficacy of intra- teeth treated without swallowed endodontic file in canal procedures, 1200 associated apical appendix resulting in apical enlargement, 1201 periodontitis, 1181–1183 acute appendicitis, 792f dressing with medication, Endogenous opioid system, 382 Erbium:YAG laser 1200–1201 pain modulation removal of debris, effective, 963, factors influencing healing endogenous opioid peptides, 964f after apical surgery, 1201 398 ERISA. See Employee Retirement irrigation, 1200 pain suppression, 398 Income Security Act apical periodontitis, teeth Endo-Rez, 1072 (ERISA) treated with associated, Endoscope visual system (EVS), 873f Escherichia coli, 232 1187 Endoscopic sinus surgery Ethylenediaminetetraacetic acid dynamics of healing, rhinosinusitis, 629 (EDTA), 1075 1199–201 Endosseous root form implants, citric acid and other acids, functional teeth, 1184 1298 1000–1002 healed teeth, 1184–1189 Endotoxin, 1103 Etiological factor of apical healing in progress, 1188 Enterococcus, 258–260 periodontitis, bacteria, apical periodontitis, teeth treated prevalence in endodontic 990 without associated infections, 259t Eubacterium, 226 dynamics of developing Enterococcus faecalis Extracellular matrix (ECM), 127, disease, 1184–1187 cells, 999f 129 functional teeth, 1188 samples of, 996f Extraction/alveolar preservation healed teeth, 1190 Enterococcus faecalis, 227 allograft hydroxyapatite, 1303f apical surgery, potential for Enzyme-linked immunosorbent atraumatic extraction, 1302f healing and retained assay (ELISA), 1028 Extraction/implant placement, function after, 1190 Epinephrine immediate dynamics of healing, 1191 containing local anesthetics and atraumatic extraction, 1302f functional teeth, 1191 all drugs, 786t final drill, surgical template, healed teeth, 1187–1188 Epiphany, 1073 1304f healing in progress, 1188 sealer, 1028f grafting the gaps, implant/bone appraisal of endodontic outcome Epoxy resin sealers, 1035–1037 walls, 1305f studies, 1171–1181 Epstein–Barr virus (EBV), 238 horizontal root fracture, 1304f exposure (treatment, EPT. See Electric pulp test (EPT) Extraradicular infections, intervention), 1175–1178 Equal employment opportunity endodontics, 243–244 outcome assessment, (EEO), 1497 apical actinomycosis, 243 1187–1179 Equipment, rubber dam, 791 Extraradicular microbial biofilms, reporting of data and analysis, adjuncts to rubber dam 283–284, 283f 1179–1181 placement, 796 appraisal of studies, 1171–1175 plastic/cement instrument/ appraisal of studies, general dental floss, 796 F considerations, 1170–1171 clamps, 795 dynamics of developing disease, variety, 795f Fair Labor Standards Act (FLSA), 1184–1187 winged clamp/wedjets cord, 1504 evidence-base for outcome of 796f Federation Dentaire Internationale endodontic treatment, dam material, 791–792 (FDI), 1036 1165–1170 forceps, 795–796 Ferric sulfate radiographic outcome rubber dam clamp selection, comparing with formocresol assessment, 1162 795t pulpotomies and selected studies comprising frame/dam combinations, 794f inference, 1429–1430 ‘‘best’’ evidence, 1181 frames, 792–795 internal resorption in a primary potential for healing and hinged rubber dam frame, 794f molar, 1416f function after latex-free barrier/U-shaped Fiber optic endoscope (orascope), nonsurgical treatment, Young’s rubber dams, 793f 873, 873f, 874f 1192–1194 punch, 792 fogging, 873 1528 / Index

Fibrefill, 1073 challenge to remove broken Ni- Giant cell granuloma, 615f Fibroblast, 127 Ti file, 1130 Ginkgo biloba, 749 Fibronectin, 355 coronal and radicular access for Glass fiber-reinforced epoxy resin Filifactor alocis, 237 instrument removal, (GFR), 1453–1455, Filling 1116–1117 1454–1455f gutta-percha versus Resilon, 1065f factors influencing fractured Glass ionomer repair lateral canal, significance of, instrument removal, perforation repair, 1128 1075, 1075f 1115–1116 Glass ionomers, 1042 success/failure of root canal File Adapter, 1119 Glickman classification system, therapy, 1056t staging platform, 1118 periodontal probing, 541 with and without radiography, Gates Glidden drills, 1117f Glutaraldehyde, 1411–1412 clinical success of, 1055t graphic representation of, GMA. See General mental ability Film, X-ray machine, 559 1117f (GMA) film placement techniques, 1128 Granulomas, 595–597 extraoral film placement, 571 Titanium instruments, Grossman’s sealer, 1038, 1069, intraoral film placement, 1117–1119, 1118f 1072. See also Zinc 557–558 ultrasonic preparation, 1118 oxide–eugenol-containing teeth, 568f ultrasonic techniques, 1117–1120 sealers hemostat, 558f design of, 1128–1129 Growth factor advantages, 561 direct contact with obstruction bone regeneration, 361 holder, 558f and activation, 1118 classifications, 360t processing, 571 use of piezoelectric ultrasonic, Guarded enthusiasm, 31 rapid-processing solutions, 1128 Gutta-balata, 1028. See also Gutta- 570–571 using a microtube system, percha table-top developing, 571 1120–1121 Gutta-percha delivery system, ‘‘Finger-powered’’ instruments, 3 creating potential for thermoplasticized First molar, 14f instrument retrieval, Calamus system, 1024–1025, Fixed partial denture (FPD), 1120f 1025f 105–106 Freeze-dried bone elements system, 1024f Flaring apex, 22 inference, 1478 UltraFil system, 1025 FLSA. See Fair Labor Standards Furcation perforation, 1127 Gutta-percha (filling material), Act (FLSA) Fusobacterium nucleatum, 237 1066 Focal infection theory, 221–223 Fusobacterium periodonticum, 237 biological objectives, 933 Food–drug interactions, 775 carrier-based, 1025–1027, 1141 Foreign body reaction Densfil, 1025 nonmicrobial aspects of disease G errors in technique, 1141 accumulation of cholesterol removal, techniques used for, crystals, 325 Galilean optics, 871f 1100–1107 cystic lesions, 320–321 Gates Glidden (GG) burs, 880, SimpliFil, 1027, 1027f root canal filling, 328 1117f SuccessFil, 107 scar tissue healing, 336–337 General mental ability (GMA), chlorhexidine, 1021 Formocresol, 1417 1501 composition, 1020t caries removal, 1407f General practitioners (GPs), 113 design objectives for cases to be placement of zinc oxide, 1408f Gene-targeting experiments, 119 filled with, 932 primary molar with stainless steel Genetic polymorphism, 343 disintegrated, 329f crown, 1408f Gene transfer systems, 249 enterococcus faecalis, 1021 pulpotomy in primary teeth, antibiotic resistance/virulence, giant cells within apical 1408f with plasmids, 252 periodontitis, 332f removal of roof of pulp chamber horizontal gene pool, 249–252 inject-R fill, 1062 and coronal pulp, 1407f pheromone-initiated conjugative lateral/vertical compaction of, studies on, 1421–1424 transfer of plasmids, 252 1062 Fractured instrument removal, GFR. See Glass fiber-reinforced undesirable stress 1115–1116 epoxy resin (GFR) concentration, 1063 Index / 1529

nickel–titanium versus stainless MTA barrier, 1337–1338 periodontal condition and steel spreaders, 1058 apexification, successful, perforation repair, observation in lateral grooves, 1337f 1129–1130 1075f pulp revascularization, restorative materials in perforation repair with 1338–1339 perforation repair, 1131 phosphate cement, 1131 immature tooth, necrotic size of perforation, 1128 plastic-embedded semithin of infected canal with apical techniques for perforation repair, apical area, 331f periodontitis, 1346f 1131–1135 properties, 1027–1028 reinforcement of thin dentinal timing of perforation repair, removal of, 1111–1112 walls, 1338 1125–1127 carrier-based, 1107–1108 traditional method, 1337 treatment sequence for heat and instrument, 1102 Hard tissue deconstruction, perforation repair, 1130 paper point and chemical mechanism of, 1361 vision and perforation repair, removal, 1102–1103 Hard tissue management and 1130 rotary instrumentation, curettage Health Insurance Portability and 1100–1102, 1108f bony window of adequate size to Accountability Act ultrasonic, 1102 perform periapical (HIPAA), 1488 versus Resilon, 1064f surgery on mandibular Heart murmurs and valvular root-filled and periapically premolar, 1250f disease, 757–760 affected left central bur, shape, 1249f antibiotic prophylaxis for dental maxillary incisor, 330f curettage of inflammatory soft procedures, 759f root filling in split tooth model tissue, 1251 antibiotic prophylaxis with straight and round curettage of soft tissue lesion recommended, 758f canal, 1062f allows for visualization of increased risk for infective sodium hypochlorite, structural mesiobuccal root apex, endocarditis, 757 effects, 1023 1251f risk of dental procedures, 758f stereochemical structure, 1021f osseous tissue response, surgical Hematogenous total joint infection, system B plugger technique, removal, 1249 767f 1061–1062 root end located following Hematopoiesis of immune cells, thermomechanical compaction, careful osseous removal, 344 1025 1249f Hemostasis, topical/local, 1258 MicroSeal System, 1022–1025 root surface distinguis, 1253 bone wax, 1258 thermomechanical compaction HBD. See Hypophosphatemic calcium sulfate, 1260 of, 1060 bone disease (HBD) collagen products, 1260 thermomechanical solid core, 1060 H&D curve, 585, 586, 586f ferric sulfate, 1259 thermoplasticized, 1023–1024 Healing, perforation and prognosis gelfoam/spongostan, 1260 and effects of heat, 1140–1141 for, 1125 microfibrillar collagen hemostat, injectable, 1061 barrier materials for perforation 1260–1261 tissue reaction to, 328f repair, 1130–1131 racellet container and pellets, ultrasonic plasticized, 1060–1061 clinical considerations 1258 vertical versus lateral, 1062–1063 influencing perforation root-end filling materials, Gutta-percha point, 90f repair based on evidence, 1261–1266 1129 surgicel, 1261 esthetics and perforation repair, thrombin, 1260 H 1130 vasoconstrictor-impregnated hemostatics for perforation cotton pellets/sponges, Hard tissue apical barrier repair, 1130 1258–1259 crown-root fractures, 1339 location of perforation, Hemostasis, vital pulp therapy, filling of root canal, 1338 1127–1128 1319–1320 ‘‘Swiss cheese’’ consistency, MTA for perforation repair, enterococcus, faecalis, 1320 1338 1129 evaluation, clinical/short-term, horizontal root fractures, 1339 perforation repair materials, 1319 treatment, 1341 1128 importance, 1319 1530 / Index

irreversible pulpitis, 1319 Human immunodeficiency virus, Hypersensitivity reactions NaOCl 768–769 innate, 368 advantages of, 1319 Human pulp, 126f types, 367–368 recommendations, 1320 Human resources, operations Hypertension, 754–755 Hemostat, straight, 558, 558f management in blood pressure classification, advantages, 559 endodontics 755f Herbal medicine–drug interactions, confidentiality/non-competition Hypophosphatemic bone disease 780 covenants, 1507 (HBD), 487 Hermetic, 1053. See also dental assistant wages, 1504t Impermeable seal EEO, 1497 Heterogenous nature of dentin employee benefit and salary I tubular, 122f administration HIPAA. See Health Insurance ERISA, 1504 IASP. See International Portability and FLSA, 1504 Association for the Study Accountability Act HIPAA, 1504 of Pain (IASP) (HIPAA) employee handbook, suggestions Iatrogenic effects, dental pulp, Histopathology of periapical for creation, 1499–1501 479–482 lesions of endodontic standard operating ‘‘blushing,’’ 480 origin procedures: computers, cavity cleansing, 481 ‘‘abscess theory,’’ 506 1500t dentin-enamel junction (DEJ), acute apical abscess, 500, 508 employee notices, posting, 1503 481 apical granuloma, 501f employee selection criteria, etching dentin/smear layer, epithelial strands in apical 1501–1502 481 granuloma, 505f GMA, 1501 cavity/crown preparation apical cyst, 506, 506f employment law, 1505–1507 heat apical scar, 508–509 law issues, 1506 cutting dentin, 480 asymptomatic apical suggestions, avoid common experimental observations, periodontitis, 507 legal pitfalls, 1506 480 cellulitis, 508 employment liability practices laser beams, 481 chronic apical abscess, 508 insurance, 1507 tooth structure, safe condensing osteitis, 508 hiring best person for job, preparation, 481 normal periapical tissues, 507 1502–1503 crown cementation, 482 nutritional deficiency theory, 506 areas to avoid, interviews, dental materials, 482 symptomatic apical 1503 desiccation by hygroscopy, 483 periodontitis, 507 job description, 1497 heat upon setting, 482 true cysts, 506 management program, elements, microleakage/cytotoxicity, 482 Historical stalwarts, endodontics, 1497 impressions and temporary 73–74 staff meetings and peak crowns, microleakage, Homeostasis phenomenon of pulp, performance, 1507–1508 482 periodontal ligament standard operating procedure local anesthetics, 479 preventing osteoclastic (SOP), 1497–1499 pins, 481 attacks, 1358 tasks/knowledge/ability tasks, Iatrogenic perforations Horizontal cone angulations, 560 1498t–1499t management, 1144 mandibular anterior teeth, termination, 1504–1505 setting of MTA and required 568–569 factors, preserve objectivity, treatment, 1124f mandibular molars, 560–565 1505 Idiopathic osteosclerosis, 608 mandibular premolars, 565–566 workers’ compensation, 1507 IHS. See International Headache maxillary anterior teeth, 569–570 Hurter and Driffield curve. See Society (IHS) maxillary molars, 566–567 H&D curve Imaging Plate, 573–579 maxillary premolars, 567–568 Hydrogen peroxide, 1002 Immune complex reactions, Host defense, 1011 Hygroscopy, desiccation by, 483 367–368 Human cytomegalovirus (HCMV), Hyperparathyreoidism, primary, Immunological methods, 230 238–240 616f Immunologic reactions, 367 Index / 1531

Impermeable seal, 1053 NF-kB and NF-kB-activating Intact coronal structure, 1296 Implant fracture, esthetic, 1307 pathways, 362–363 Intentional replantation, 1220–1221 Implant surgery molecular mediators of Intentional teeth replantation, 67–69 endodontic endosseous implants, proinflammatory Interactions, microorganisms, 1294 response 249–257 osseointegrated implants, 1295 adhesion molecules, 352 antibiotic resistance and Incisive canal cyst, 613f chemokines, 352 virulence associated with Indirect pulp therapy, 1425 plasma proteases, 353 plasmids, 252 Inferior alveolar nerve (IAN), 714 coagulation cascade and cooperative/antagonistic, Inflamed dental pulp fibrinolytic systems, 354 253–254 acute inflammatory process, 381 complement system, 354 extra-chromosomal DNA, Inflammation, 344 kinin system: bradykinin, horizontal gene pool, Inflammation and immunological 353 249–252 responses matrix metalloproteinases, gene transfer systems, 249 -defensins, 348 354–355 pheromone-initiated conjugative cells of adaptive immunity, neutrophil elastase, 355 transfer of plasmids, 252 348–351 platelet-activating factor, 352 plasmids in oral and endodontic cells of innate immunity, 344–348 neuropeptides, 358–359 microflora, 253 cytokines nitric oxide, 355 species-specific interactions, proinflammatory cytokines, oxygen-derived free radicals, microorganisms in root 356–358 355–356 canal infections, 254–256 systemic effects of, 358 toll-like receptors, 359–360 International Association for the growth factors, 360–361 Inflammatory mediators, 383 Study of Pain (IASP), 393 hypersensitivity reactions, Inflammatory response, 343, 352, International Headache Society 367–368 353, 353f, 357, 358, 468 (IHS), 426 inflammation-induced bone Infraorbital nerve block injection, International Standards resorption 721 Organization, 573 inhibition of bone resorption Ingle’s MBD rule, 561, 564, 935 Interradicular periodontal lesions, 69 by bisphosphonates, 366 Inhibition of bone resorption by Intracanal disinfection procedures, mechanisms of bone bisphosphonates 241 resorption, 364–365 mechanism of bisphosphonate Intracanal irrigation, 696 microbial role in pathogenesis (BP)-induced, osteoclast Intracanal medicaments containing of periradicular lesion, apoptosis, 366, 365f antibiotics, 1011 363 Innate immune system, 344 Intracanal medications, cements, role of immune cells in phagocytosis, 345 and filling materials, periapical lesion Innate immunity, cells of 772–773 formation, 364 comparison of mast cells and Intracanal microbial biofilms, roles of cytokines in basophils, 347t 279–283, 279f periradicular bone dendritic cells (DCs) and NK Intranasal drug (IN drug), 746 resorption, 366–367 cells, 347–348 Intraoral X-ray sensors, diversity innate and adaptive immune eosinophils and basophils, 347 of, 575f systems, 344–345 odontoblasts, 348 Intravenous conscious sedation, MHC and antigen presentation, PMNs and macrophages, 743–745 351–352 346–347 Iodine potassium iodide, 1006 molecular mediators of anti- Instrumentation and irrigation, 242 IRM, 1043 inflammatory reactions Instrumented and uninstrumented Irrigants and intracanal anti-inflammatory cytokines: root canal wall after medicaments, 992 IL-10, TGF- , IL-4, and irrigation, 1000f, 1001f, alternatives for interappointment IL0–0, 362 1007f medicaments membrane phospholipids/ Instrument Removal System (iRS), intracanal medicaments arachidonic acid 1107, 1108f, 1120, 1121 containing antibiotics, metabolic pathways, clinical case utilizing, 1120f 1011 361–362 Insular cortex (IC), 398 phenol compounds, 1011 1532 / Index

developments in root canal K parameters, while operating disinfection, 1009 laser, 874f effect of instrumentation on root Kava, 787 principles of operation canal microbes, 993–994 Kerr Broach, 2f LASER beam, 857–859 elimination of microbes in root Kerr pulp canal sealer EWT, 1069 ‘‘surgical’’ beam, 857 canal system, 992–993 Ketac-endo, 1071 pulpal diagnosis, 859 goal of endodontic treatment, 993 Khat, 787 LDF, 859 infection control in human body, pulp capping/pulpotomy, 992 859–860 instrumentation of root canal, L mineral trioxide aggregate 985 (MTA), 1030–1033 intracanal interappointment Lactobacillus casei, 245 radiograph, vertical root medicaments Lamina dura, 564–566 fracture, 879f Ca(OH)2, 1006–1007 Laser-assisted canal preparation, schematic diagram of laser, 873f CHX, 1002–1006 962–964 wavelengths, laser types physical means of canal cleaning limitations of, 964 according to emission and disinfection removal of debris using spectra, 873f lasers, 1008–1009 erbium:YAG laser, 989f Lasers, 1428 ultrasonic cleaning, 1007–1008 effective, 990f compared with four pulpotomy root canal disinfection by shaping of single rooted teeth, techniques, 1415 chemical means 989f in endodontics, 1005–1006 antibacterial irrigating use in endodontics, 968 Lasers in Endodontics, 857 solutions, 997 Laser beam, 857–861 Lateral canals CHX, 995–1003 Laser doppler flowmetry (LDF), clinical aids for identification, EDTA, citric acid and other 859 640 acids, 1000–1002 applications. See Applications of detection, 640 hydrogen peroxide, 1002 LDF, dentistry vessels, 131f iodine potassium iodide, 1006 laser Doppler setup, example, 548f Latex, use of, 770 NaOCl, 997–1001 potential modalities, 551–552 LDF. See Laser Doppler antibiotic-containing technology, development and Flowmetry (LDF) irrigation solutions principle, 547 LDF technology, development/ MTAD and tetraclean, Fast Fourier Transform (FFT) principle, 547–549 1006–1007 analysis, 548 Licorice, 787 challenges, 994 laser Doppler machine, LightSpeed (LSX), 944 ex vivo and in vivo models, readout, 563f Lightspeed NiTi rotary instrument, 995–997 use and development, 552 805 in vitro models, 994–995 Laser in endodontics Limited liability company (LLC), Irrigating solutions, 771 apical surgery, 865–866 1481 Irrigation dynamics, 967–968 preparation of apical cavities, Limited liability partnership (LLP), effect of sizes and canal Er:YAG laser/ultrasonics, 1481 diameters needle position, 866 Lipopolysaccharide (LPS), 224, 967f cleaning/disinfecting, root canal 245–246, 468 irrigation performance and size system, 860–864 Lipotechoic acid (LTA), 246–247, of needle, 968 intra-canal use of lasers, 468 Ischemic heart disease, 756–758 limitations, 861 Liver disease, 769 treatment modification, 757 endodontic retreatment, 865 LLC. See Limited liability laser interactions, basic types, company (LLC) 874f LLP. See Limited liability J laser irradiation, 878f partnership (LLP) obturation, root canal system, Loading protocol, immediate Japanese 864–865 additional requirement, 1306 and one appointment therapy, 21 thermoplasticized compaction, advantages, 1315 Journal of Endodontia, 36 concept, 864 Local anesthetics, 768 Index / 1533

and all drugs, 783 IAN block injections, 716 radicular third root EPT, 714 factors, for success, 717 bifurcation, 196f preliminary factors, clinical trial lack of success, 716 two canals and two roots, 194 literature, 713 reasons, lack of success, 716 Mandibular central incisor Loupes, visual enhancement intraligamentary injection, canal system, 181–183 single/multi lens loupes, 870 supplemental, 717–718 number of canals and apices, Low-compliance system theory, effects, potential adverse, 717 179 135 intraosseous shape, 184 LPS. See Lipopolysaccharide (LPS) anesthesia delivery system external root morphology, 184 LPS-binding protein (LBP), 346 X-tip, 737f labial and mesial view, 185f LTA. See Lipotechoic acid (LTA) characteristics, 718–720 root cross-sections, 185f Luxation injuries stabident system, 718 length of, 184 definitions intrapulpal injection, 720 versus mandibular lateral incisors concussion, 1347 long-acting local anesthetics, 715 exihibiting fusion, 188f direction, 1342 mepivacaine, 715 number of canals, 183t extrusive, 1342 prolonged pain control, 715 root number and form, 184 lateral luxation, 1347 ropivacaine, 716 1 root and 1 canal, 186f subluxation, 1353 time-response curve, two canals trauma, types, 1354 development of pulpal connecting apical third web- external/internal inflammatory anesthesia, 712f canal and one apical root resorption, 1343 VGSC, 716 foramen, 187f Mandibular anterior teeth and one apex, 187f horizontal cone angulations, two separate apical foramina, M 560–570 188f horizontal X-ray projections, 583f variations and anomalies, 186 Macrolides projecting directly through dens invaginatus, 184 potential reactions between canine, 584f fusion, 188f macrolide antibiotics and Mandibular canines gemination, 188–189, 189f all drugs, 783t anatomy and morphology, Mandibular first molars Macrophage colony-stimulating 909–913 achieving SLA, 939f factor (MCSF), 365 versus mandibular incisors, anatomical variations in, 940f Macrophages, 327 912 anatomy and morphology, activation and function, 346f canal system, 188, 188t 915–916 Macrophages release somatostatin clinical, 913–914 canal system, 210 (SRIF), 502 external root morphology, three-rooted, 205t Major histocompatibility complex 191–192 two-rooted, 209t (MHC), type II, 470 labial and mesial view, 194f clinical, 919–921 Malignant tumors in jaws, 617 mesial curvature of root in distal canal, 915 Malpractice/negligence, common apical third, 196f external root morphology, elements, 86t 1 root and 1 wide canal, 195f 205–206 Management (winning) practices, root cross-sections, 195f buccal and mesial, 209f, 210f operations management labial, mesial, and incisal views, root cross-sections, 210f in endodontic practice 933f 2 roots and 3 canals, 210f, 211f focusing matrix, 480t root number and form, 193, 193t length of, 206 measuring customer defections, similarity to maxillary incisors, with periapical lesion, 1165f 1479t 930f presence and impact of furcation primary, 1479–1480 treatment sequence of two canals canals, discussion, 915 secondary, 1480 in, 934f root and root canal anatomy Mandibular anesthesia, 714–716 variations and anomalies, 197 of distal root, 932t adverse effects, 722 dens invaginatus, 197, 198f of mesial root, 932t articaine, 715 fusion, 191 root number and form, 209–210 bidirectional rotation method, gemination, 197, 198f Mongoloid versus non- 716 presence of two canals, 191 Mongoloid, 206–208 1534 / Index

number of roots, 208t fin or groove with pulp tissue C-shaped canals, 915 searching middle mesial canals, between them, 928f, 910 external root morphology, 205 939, 940f labial, mesial, and incisal views, buccal and mesial view, 214f variations and anomalies, 890f, 905f root cross-sections, 215f 209–210 root and root canal anatomy, 2 roots and 3 canals, 215f, 216f extra canal, 213f 912t length of, 216 supernumerary roots and Mandibular lateral incisors root number and form, 206, 208t canals, 213f, 214f canal system, 191t variations and anomalies, 209–210 taurodontism, 214f shape, 191 additional canals, 218f Mandibular first premolars two canals and one apical C-shaped canal, 216 anatomy and morphology, 909 foramen, 192f fused or single roots, 209, 210f bifurcated teeth, 193 external root morphology, 187 two canals, 210f buccal, mesial, and occlusal labial and mesial view, 188f variations in anatomy, 926f views, 935f root cross-sections, 189f Mandibular second premolars canal system, 201–202 length of, 187 anatomy and morphology, 915 number of canals and apices, root number and form, 187–188, buccal, mesial, and occlusal 204t 190t views, 928f clinical, 915 1 root and 1 canal, 190f canal system, 208–209, 208t external root morphology, 1 root and 1 canal with incidence of two or more 191–193 multiple lateral canals, canals, 200 buccal and mesial view of, 199f 190f clinical, 915 root cross-sections, 200f separation of single canal into external root morphology, length of, 198 2 canals, 190f 202–203 versus mandibular second variations and anomalies, 191 buccal and mesial view, 205f premolar dens invaginatus, 191 root cross-sections, 205f number of canals and apices, fusion, 192, 193f single root and single canal, 204t gemination, 192, 193f 194f separate canals, 209 Mandibular molars length of, 203, 205 removal of more buccal cusp access preparations, 918f, 938f root number and form, 205t, 206 than lingual, access moderate/severe root variations and anomalies, 205 cavity, 936f curvature, 937f dens evaginatus, 200, 200f root and root canal anatomy, buccal mesial occlusal views, two canals, 200, 201f 912t 936f two roots, 208 root number and form, 203 four canals, 578f Mandibular third molars main buccal and vestigial mid- horizontal cone angulations, anatomy and morphology, root lingual root, 195f 560–570 915–916 single root and single canal, hourglass-shaped canal, 579f clinical, 922 194f, 195f and lamina dura, 565–566 Master apical file (MAF), 880 Tome’s root, 193 lingual and mesial inclination of, Matrix database elements, two root canals, incidence, 880 diagnostic software 199–200 ‘‘opening up’’ roots, 571f (AEL), 850f variations and anomalies, 200 root canal-treated, 928f Matrix metalloproteinase (MMP), rare three-rooted, 202f standard horizontal X-ray 127, 354, 355t three canals and two roots, projection, 561f Maxillary anesthesia 196, 196f Mandibular premolars anterior middle superior alveolar three canals in single root, 196, first premolar, 580f (AMSA), 721 196f horizontal cone angulations, infraorbital nerve block Mandibular incisors 560–570 injection, 721 anatomy and morphology, 909 Mandibular second molars, 209 palatalanterior superior alveolar buccal and lingual canals with anatomy and morphology, 915 (P-ASA) injection, 721 separate apical foramina, canal system, 213–215 Maxillary anterior teeth 916f two-rooted teeth, 216, 209t horizontal cone angulations, clinical, 909 clinical, 921 560–561