continuing Education R aestor tive In sIDe Periodontics

Bleaching the Single Dark Tooth Learning Objectives Changing the color of just one anterior tooth presents unique challenges. • identify the causes of tooth discoloration in the initial examination. By Van B. Haywood, DMD | Anthony J. DiAngelis, DMD, MPH • discuss how tooth trauma impacts the approach to tooth bleaching. • discuss how endodontic treatment impacts there is no reason to initiate endodontic the approach to tooth bleaching. Abstrt ac therapy based on vitality testing alone. • describe each possible bleaching approach, Single dark teeth represent a major challenge to obtain best esthetic outcome in a Often single dark teeth are the result of the indications for each, and its benefits. patient’s smile. Treatment options may include single crowns, veneers, bonding, or trauma, which should be determined in bleaching. Bleaching is the most conservative option to consider, but the potential the dental history. It can take anywhere Logno o t www.insidedentistryCE.com for a successful outcome varies based on the cause and extent of the discoloration. from 1 to 20 years after the trauma be- to take the FREE CE quiz. fore any pulpal problems develop. Additional considerations for the occurring injury in permanent teeth.10,11 single dark tooth are the color of the Also, studies have reported that 71% to hen a patient must be aware of the basic principles of gingival tissues around the tooth, as well 92% of TDIs occur by age 19.12 presents with changing the color of one or more teeth as whether there is any root structure T he etiology of dental injuries varies either intrin- in order to implement a successful treat- visible due to recession. A smile analysis by age. In the 0 to 6 age group, falls pre- sic or extrin- ment plan. is used to determine these conditions as dominate.13 As children enter school, sic staining or well as the movement of the lip during falls, collisions with other children discoloration The Initial Examination smiling and whether a “gummy smile” and objects, as well as participation in and seems to T he first and most important con- exists. The dentin in the root is differ- organized physical activities and sports be a candidate for tooth bleaching, there sideration is to determine the cause ent from the dentin in the anatomic contribute to dental injuries.9,14-16 Tdis Wis a variety of factors and options for the of the tooth discoloration. A clinical crown, and does not bleach well if at in the teen and young-adult age group clinician to consider. What is the cause examination is conducted, which in- all, regardless of whether internal or are more the result of sports and motor for the discoloration? Is there tooth cludes evaluation of the color of the external bleaching is attempted. Also, vehicle accidents.14 Several studies have trauma involved, or has the affected teeth and the adjacent gingiva (Figure discolorations of the gingiva may cause documented that approximately one tooth been endodontically treated? 1). Additionally, transillumination, ra- a tooth that may be a perfect color match third of dental injuries are sports-re- What is the best delivery method for diographs, and pulp testing may be ap- to not be harmonious. Either of these lated.15-23 Other causes of TDIs include the patient’s lifestyle, financial situation, propriate. Radiographs should always conditions is magnified if the lip exposes physical abuse, fights, and assaults—of- and commitment level to home care? be taken of a single dark tooth, as teeth much of the root or gingiva because of a ten involving alcohol as an aggravating Single dark teeth present a unique chal- can undergo pulpal necrosis without hyperactive lip or gummy smile. factor.24-26 lenge for color change and the clinician any other symptom than becoming dark T he pulp can respond to trauma in (Figure 2). From this examination, the Trauma and Calcific a limited number of ways. Primarily it Van B. determination is made of whether the Metamorphosis can survive, die, or undergo pulp canal Haywood, DMD tooth is vital or not. A vital tooth may Many studies suggest that the preva- obliteration (PCO), often referred to Professor be darker due to trauma and resultant lence of traumatic dental injuries (TDI) as calcific metamorphosis.27 The latter Director of Dental bleeding into the dental tubules with- is high, although significant variation represents a common finding subse- Continuing Education Department of Oral out loss of vitality. Vital teeth may also occurs between countries, populations, quent to luxation injuries, 3.8% to 24%, 1-4 2,28-30 Rehabilitation discolor from internal or external re- age, and gender. Epidemiological and root fractures, 69% to 73%. School of Dentistry sorption, calcific metamorphosis, as well studies, while not always comparable, The precise mechanism of PCO is not Medical College of Georgia as decay or leaking restorations on the support the growing body of evidence known but disruption of the neurovas- Augusta, Georgia proximal or lingual surfaces. A non-vital that Tdis represent a significant chal- cular bundle appears to stimulate the tooth may have become darker from the lenge for clinicians.5 A study by Koste rapid formation of hard tissue (dentin Anthony J. same reasons as a vital tooth, but also and colleagues reported that 25% of or osseous) beginning within the pulp DiAngelis, DMD, MPH have experienced pulpal death. A tooth 6- to 50-year-olds in the United States chamber and progressing along the Chief Department 6 31 of Dentistry that has received endodontic treatment had experienced a TDI. Approximately pulp canal walls. It may present as Hennepin County may also later darken, especially if there 30% of children have sustained a TDI to partial or total obliteration of the pulp Medical Center is a poor seal of the endodontic access their primary dentition, and 25% of all canal space. Although radiographs may Minneapolis, Minnesota opening (Figure 3). school-aged children have experienced reveal what appears to be total oblitera- E ven if a tooth tests as non-vital, it a Tdi.7-9 Other reports document that tion of the pulp canal, generally there Professor University of Minnesota may not require endodontic therapy. If luxations represent the majority of remains clinical evidence of a pulp 32,33 Minneapolis, Minnesota there is no radiographic evidence of pa- primary teeth injuries, whereas crown canal and pulpal tissue. Clinically, thology and no clinical symptoms, then fractures constitute the most commonly the tooth will appear dark yellow due

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to the increased deposition of under- restorative procedure. A recent article the form of a discolored incisor presents bleaching efficacy.44 It is not possible lying dentin. Additionally, there may by daCunha and colleagues suggests a long-term esthetic challenge. The most to “spot bleach” a tooth either, because be a gradual diminution in response implementing endodontic therapy prior conservative approach to managing the bleaching material goes through to electrical and thermal pulp testing. to development of a periapical radiolu- PCO-induced discoloration is bleach- the enamel and dentin to the pulp in 5 PCO occurs more frequently in teeth cency in a tooth with PCO, based on two ing without endodontic therapy. to 15 minutes, and bleaches under res- with open apices and in more severe major considerations: (1) the technical torations and from one surface to the luxation injuries involving displace- difficulty and complications that may Tray Bleaching other (facial to lingual). It has also been ment.2,34 Extrusive and lateral luxation occur in treating these teeth; and (2) T here are a number of types of bleach- shown to bleach beyond the borders injuries in immature permanent teeth their review of a study that demonstrat- ing techniques to consider for both vital of the tray, generally to the cementoe- have demonstrated high rates of PCO.35 ed a 97.9% success rate for teeth treated and non-vital teeth, but these types may namel junction (CEJ), even if the tooth A recent study by Netto and colleagues without periapical radiolucencies vs a be divided mainly into those performed is only partially erupted. reported the chances of PCO in in- 62.5% success rate for teeth treated with in-office or those continued at home. T he ideal bleaching tray is fabricated truded permanent teeth to be six times periapical radiolucencies.42 Specific With the advent of nightguard vital on a horseshoe-shaped cast with no greater than in mature teeth, open vs clinical situations will dictate clinical bleaching involving tray application vestibule to provide good adaptation closed apex, and that PCO occurred in decisions; however, given the relatively of 10% carbamide peroxide, a method of the bleaching tray material. Also, the 26.7% of such injuries.36 PCO can oc- low incidence of pulp necrosis in teeth for bleaching single dark teeth became cast should be trimmed such that the cur in subluxated and crown-fractured with PCO, endodontic treatment usually more readily available, and did not in- central incisors are vertical to avoid teeth, although with less frequency.37 is not recommended in the absence of volve the use of highly caustic chemi- folds on the facial. One challenge in As mentioned previously, PCO is a a periapical radiolucency or symptoms. cals.43 The original recommendation fabrication of the single-tooth or regu- common occurrence after root frac- N onetheless, if a periapical lesion de- for a single dark tooth was to make a lar bleaching tray is trimming the cast tures. The location of PCO is thought velops, endodontic therapy can be both non-scalloped, no-reservoir tray, and without abrading either the teeth or the to be indicative of the type of healing. challenging and fraught with complica- bleach all the teeth. The tooth that was gingiva. This outcome is accomplished PCO in the apical segment only is sug- tions (Figure 4). The use of operatory darker generally took longer, so an “X” by trimming the cast from the base gestive of hard-tissue callus formation, microscopes in the hands of a skilled was made on that tooth mold of the tray rather than the sides (Figure 5). whereas PCO in the coronal segment or clinician is warranted and improves the so the patient could continue to bleach in both coronal and apical fracture seg- chances of a successful outcome. that tooth longer than the other teeth. Single-Tooth Bleaching Tray ments is indicative of connective tissue Most traumas to primary teeth are T he use of the “X” on the teeth to be An improvement on this concept is repair of the fracture.2,38 luxation injuries that frequently result in bleached was also helpful when the pa- the use of the “single-tooth” bleaching Pulp necrosis as evidenced by periapi- radiographic evidence of PCO. Although tient already had crowns on some teeth, tray when one tooth is darker, but the cal radiolucency is an infrequent sequela this may or may not result in crown dis- and placing bleaching material on them other teeth are reasonably acceptable to PCO occurring in approxi­mately 7% coloration, it ceases to be a concern for was a waste of material. While this tray (Figure 6). In this tray design, a conven- to 16% of cases; consequently, prophy- the patient, parent, or clinician as the system was simple and effective, it did tional non-scalloped, no-reservoir tray lactic endodontic therapy is not recom- tooth is eventually exfoliated. The only not always result in a perfect match of is fabricated. Then the teeth molds on mended by most authors.28,39-41 T eeth indication for bleaching primary teeth, the teeth. All the teeth would lighten, either side of the dark tooth are removed with PCO likely have diminished heal- which are generally very light, is trauma but often the darker tooth was not able (Figure 7 and Figure 8). The patient is ing capacity, and it is not well established that caused the tooth to become dark and to lighten as much as the normal teeth, given one syringe of bleaching mate- whether a secondary trauma or addi- the patient is being affected psychologi- and the resultant outcome was lighter rial and applies it only to the single dark tional dental treatment causes necro- cally by the darker teeth. There is no in- teeth, but still with one tooth slightly tooth mold and sleeps in the appliance. sis. In some instances, such as prepar- dication for endodontic therapy. darker than the others. Some authors T eeth will bleach at different rates and ing a tooth with PCO for an abutment, it I n contrast, younger patients who have recommended using a reservoir to different color levels.T he goal is to de- may be prudent to perform prophylactic sustain Tdis where development of the on the darker tooth, but the use of res- termine how light the single dark tooth endodontic therapy before the definitive permanent tooth is incomplete, PCO in ervoirs has not been shown to increase will bleach first.I f the color of the single

fig. 1 fig. 2 fig. 3 fig. 4

CLINICAL EXAMPLES (1.) A clinical examination demonstrates a single, very dark lateral incisor CLINICAL EXAMPLES (3.) A radiograph will indicate wheth- and a moderately dark central incisor with a crown on the adjacent central incisor and several er the dark color is related to materials remaining in the pulp dark gingival areas. (2.) A radiograph finds no pulp chamber in the slightly dark central incisor chamber, leaking restorations, caries, internal resorption, and a silver point on the darkest lateral incisor. A titrated approach to bleaching was needed us- or failed endodontic therapy. (4.) Endodontic therapy was ing individual tooth treatments. attempted on a tooth with calcific metamorphosis, with subsequent perforation and file fracture in the PDL.

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dark tooth does not get as light as the sur- been subsequently restored with an ac- rounding teeth, then the other teeth are ceptable lingual composite that matched not bleached (Figure 9) and the closest the tooth color. However, in subsequent match has been achieved. If the single years, the tooth may have discolored dark tooth matches the other teeth then, (Figure 10). In this situation, the deci- again, the other teeth are not bleached. sion for bleaching favors external bleach- Only if the single dark tooth gets lighter ing, because going inside the tooth to than the adjacent teeth should they remove the composite will weaken the be bleached, and in that case, daytime tooth (Figure 11). However, the choice fig. 5 fig. 6 bleaching in short intervals should be not to go inside the endodontic tooth used to avoid getting the adjacent teeth depends on whether the treating dentist lighter than the single dark bleached is aware of the extent to which the pulp tooth. Generally, the patient should be chamber was debrided during endodon- informed that the bleaching time for tic therapy, as well as the height in the the single dark tooth is about 8 weeks, chamber of the cement and filler. although it is highly variable. In-Office Bleaching fig. 7 fig. 8 “One challenge in I n-office bleaching is the oldest form of bleaching. Attempts to bleach single fabrication of the dark teeth date back to the 1800s, and single-tooth or regular bleaching a single dark tooth was one of the first bleaching research areas.45 bleaching tray is A number of materials have been used, trimming the cast but hydrogen peroxide has been the historic favorite. The high concentra- without abrading tion of hydrogen peroxide could be either the teeth or the applied externally or internally, and often involved heat and light. The gingiva. This outcome classic non-vital in-office bleaching is accomplished technique involved the placement of 35% hydrogen peroxide into the pulp by trimming the cast chamber, and increasing the chemi- from the base rather cal reaction by the use of heat or light. fig. 9 However, this technique lacks precise than the sides.” control as to the amount of lightening. More critically, when cases of external Endodontically Treated or internal resorption were evaluated, Anterior Teeth there were four common concerns list- I f the dark tooth has already received ed: 1) teeth had received trauma; 2) high endodontic therapy, then additional concentrations of peroxide were used; considerations for the discoloration 3) high heat was used to enhance the fig. 10 fig. 11 include remaining pulp materials in bleaching, and 4) there was no seal over the pulp chamber, endodontic sealer the gutta-percha. Although the dentist CASE EXAMPLE ONE (5.) Trimming the cast only from the base (with the or filler in the pulp chamber, and dark or cannot control the trauma, elimination central incisors horizontal) until the vestibule is removed and a hole oc- leaking restorations in the endodontic of the other three areas under dental curs in the palate will avoid the danger of damaging teeth from traditional trimming as well as create the best cast for use in a vacuum-former. (6.) A access opening, as well as endodontic control should be done to lessen the single dark tooth from trauma needs to be examined carefully and evalu- failure. The type of filler is also impor- chances of resorption and loss of the ated with a radiograph. The safest approach is to bleach this tooth alone tant, as silver points require different tooth. Other possibilities for resorp- until the tooth’s response and maximum lightening can be determined. (7.) The “single-tooth” bleaching tray has no reservoir or spacers and extends considerations from gutta-percha fill- tion include the fact that 10% of teeth onto the gingiva 1 mm to 2-mm, but avoids frenum movements. The teeth ers. Treatment considerations also do not have a connection between the not to be bleached have the tooth molds removed from the tray while may depend on when in the endodontic enamel and cementum, with possible maintaining the intact tray. (8.) The single-tooth bleaching tray extended further onto the palate than the traditional tray to preserve the tray treatment and subsequent follow-up percolation of hydrogen peroxide into integrity when the adjacent teeth molds were removed from the tray. The the tooth was noticed to be dark. the surrounding areas, lowering the pH. tray edges are hidden behind rugae and go onto the tissue in all areas. Endodontically treated teeth may be Using a bleaching product with a higher (9.) A reasonable match was obtained from about 8 weeks of single-tooth bleaching. Often patients discontinue treatment when the single tooth is treated from the inside, the outside, or pH or a salivary catalase are attempts no longer a mismatch, even if the outcome is not ideal. CASE EXAMPLE both. The decision for inside or outside to reduce resorption issues. TWO (10.) This root canal has been successful for 30 years, but the tooth depends on a knowledge of what has has become slightly discolored. There is no reason from the radiograph to re-enter the pulp chamber, as this will further weaken the tooth. External occurred inside the tooth during the Walking Bleach Technique bleaching by a single-tooth bleaching tray is indicated (11.) The 10% carb- endodontic therapy, as well as the type T he change in in-office bleaching led amide peroxide bleaching material was applied externally with the single- of restoration used to seal the access to the next step of “walking bleaching.” tooth bleaching tray nightly until the shade of the endodontically treated tooth returned to match the adjacent teeth. Should the tooth re-darken opening. The tooth may have received a I n this technique, the gutta-percha was again, the process can be repeated without danger to the tooth. Figure 10 satisfactory endodontic treatment and removed 2 mm below the CEJ and a and Figure 11 courtesy of Meigan Johnson.

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base was applied to seal the endodontic Inside Bleaching filling material from the pulp chamber. When performing internal bleaching Then, initially, a high concentration of on a non-vital tooth that has received hydrogen peroxide was applied, sealed, endodontic therapy, it is important to and the patient “walked out of the office” clean out the inside of the pulp cham- while the hydrogen peroxide oxidized ber (Figure 12). Often, when endodon- the discoloration. This treatment took tic therapy is performed because of anywhere from 1 to 6 weekly applica- trauma, the pulp chamber is large, with fig. 12 fig. 13 tions. The challenge was that the high high pulp horns. The access opening concentration of hy­drogen peroxide to the apex may not include debride- could be caustic to either the dentist ment of the chamber (Figure 13). The or the patient. Later, this technique restorative dentist should open the evolved into mixing the hydrogen per- access opening enough to access both oxide with sodium perborate to form the incisal extent as well as the lateral a mixture that was easier to handle. extent of the pulp chamber. Often, re- Sodium perborate breaks down into moval of the remaining pulp chamber fig. 14 fig. 15 about a 3% solution of hydrogen per- will significantly alter the color of the oxide. Finally, the high concentration tooth, even before the bleaching has of hydrogen peroxide was eliminated begun (Figure 14). and sodium perborate alone was used. I nternal bleaching treatment was fol- Inside-Outside lowed by the use of a catalase to neu- Closed Bleaching tralize the hydrogen peroxide and el- One of the best options for an endodon- evate the pH around the tooth. With tically treated tooth is to use both the any bleaching treatment, time should inside and outside techniques in combi- fig. 16 fig. 17 be allowed for the shade to stabilize and nation. Entering the inside of the tooth the oxygen to dissipate from the tooth. will allow removal of any pulp tissue, If bonding is initiated immediately af- filler, or cement sealer, as well as discol- ter bleaching, there is a 25% reduction ored restorations in the chamber. The in bond strengths due to the inhibition classic walking-bleaching treatment is of the composite set from the oxygen in performed as described above (Figure the tooth, resulting in shorter enamel 15 and Figure 16), then the tooth is tags. It generally takes about 2 weeks temporarily sealed while a single-tooth or longer for the shade to stabilize and bleaching tray is fabricated. Bleaching the bond strength to return to normal. continues at home externally using the Later, 10% carbamide peroxide was single-tooth tray approach until the sin- found to be equally as effective as so- gle dark tooth has reached its maximum dium perborate for internal bleaching, lightness (Figure 17). Then the patient at the same concentration, with the waits 2 weeks for the shade to stabilize additional benefit of causing a rise in and the bond strengths to return to f ig. 18 pH, which may be beneficial to avoid normal. Upon return to the dentist, a resorption. A 10% solution of carb- comparison of the single tooth is made CASE EXAMPLE THREE (12.) The initial examination and radiograph determined that the dark lateral incisor was abscessed. After endodon- amide peroxide is equivalent to 3.5% to the adjacent teeth. If the endodon- tic therapy, the tooth was then ready for bleaching. Had bleaching been hydrogen peroxide and 6.5% urea. It tically treated tooth remains slightly performed without the radiograph, the abscess would have remained is the urea that causes the increase in darker than the remaining teeth, an untreated and further damaged the tooth. (13.) The endodontic access opening should be enlarged until it can be certain that all the remaining pH within 5 minutes after application opaque stark-white composite is used brown pulp tissue has been removed from the lateral walls of the pulp to a level above 8, which cannot be ac- internally to fill the pulp chamber and chamber as well as the incisal extent. Pulps that became necrotic when complished with hydrogen peroxide provide an additional slight lightening the tooth was young often have pulp chambers much larger than the endodontic access opening. (14.) Even before bleaching the tooth, the re- alone. Also, the carbamide peroxide of the tooth (Figure 18). The final ori- moval of the brown necrotic pulp remnants and dental materials makes the has a slower peroxide release and is fice is closed with the appropriate color- tooth much lighter. This occurrence demonstrates how the materials inside active longer than hydrogen peroxide. matched composite to the external por- the tooth affect the color of the outside. (15.) For internal bleaching, the gutta-percha should be removed 2 mm below the CEJ. (16.) Once the gut- T his slower application of peroxide tion of the tooth. Some clinicians prefer ta-percha has been removed to the appropriate depth and from the walls seems to favor the rate of color change. to use a resin-modified glass ionomer of the pulp chamber, the endodontic filler is sealed from the pulp chamber Because trauma is one of the initia- internally to improve the bond to dentin, with a resin-modified glass ionomer. Etching is not required for bleaching. (17.)The patient may bleach externally (as well as internally) with a full tray tors of resorption, that event cannot followed by the traditional composite rather than a "single-tooth tray" to lighten all the teeth or because there be totally eliminated. Even teeth that restoration to close the opening. This are crowns that will not change color. To identify the dark tooth for ad- have not been bleached can begin to approach of both inside and outside ditional treatment, an “X” is placed on the tooth mold for the placement of the bleaching material. If the tray is to be worn during the day rather have resorption, so there is always that bleaching with a closed pulp chamber than at night, the “X” should be placed on the lingual. (18.) After the tooth possibility. Traumatized teeth should gives the benefits of both techniques. being bleached has reached its maximum lightening, the bleaching process have recall radiographs taken every T he inside bleaching segment allows should be stopped for 2 weeks to allow the shade to stabilize and the bond strengths to return to normal. Then an opaque whiter composite can 1 to 2 years, whether they have been the tooth to be cleaned as well as tem- be placed in the chamber if needed to further harmonize the tooth color. bleached or not. pers the final color with a composite

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restoration, while the outside bleaching single-tooth tray, then the standard re- adjacent tooth colors. A “single-tooth” 10. Hedegård B, Stalhane I. A study of trauma- segment allows the patient to bleach as placement of the internal carbamide bleaching tray is the tray of choice for tized permanent teeth in children aged 7-15 long as necessary to obtain the maxi- peroxide is performed weekly, taking 1 external bleaching. Single dark teeth years. Part 1. Swed Dent J. 1973;66:431-450. mum whitening of the tooth without to 6 office visits for completion. A pro- with calcific metamorphosis should not 11. Gelbier S. Injured anterior teeth in chil- returning to the office (Figure 19 and visional restoration maintains the seal, be treated endodontically unless there dren. A preliminary discussion. Br Dent J. Figure 20). Because a cast already ex- and the patient is instructed to call the are clinical symptoms of pain or radio- 1967;123:331-335. ists for the single-tooth tray, should the office immediately if occlusion or food graphic evidence of an abscess. 12. Davis GT, Knott SC. Dental trauma in single tooth get lighter than adjacent disrupts the provisional seal. For internal bleaching of an end- Australia. Aust Dent J. 1984;29:217-221. teeth, a new bleaching tray can be fab- odontically treated tooth, a “walking 13. Kramer PF, Zembruski C, Ferreira SH, ricated and the patient can use it for Bleaching or Crown Decisions bleach” approach using 10% carbamide Feldens CA. Traumatic dental injuries in day wear to titrate the color to a final T he question is often asked why the an- peroxide internally seems to afford Brazilian preschool children. Dent Traumatol. match. The average treatment time for terior endodontically treated tooth is the safest approach over previous tra- 2003;19:299-303. single dark teeth seems to be 8 weeks, not crowned today as it once was in the ditional methods. The combination of 14. Skaare AB, Jacobsen I. Dental injuries in although there is a wide range of treat- past. One reason for the resurgence of one internal bleaching appointment to N orwegians aged 7-18 years. Dent Traumatol. ment times. While 10% carbamide per- bleaching single anterior teeth is that debride the pulp chamber, followed by 2003;19:67-71. oxide is generally used for traditional the research has shown that while pos- tray bleaching with a single-tooth tray or 15. Hosnik A. Emergency treatment of dentoal- overnight treatment, higher concentra- terior teeth that have received a root ca- full non-scalloped, no reservoir tray pro- veolar trauma. Phys Sports Med. 2004;32(9):1-10. tions may be used once it is determined nal should be crowned, anterior teeth vides the flexibility of unlimited time of 16. Onetto JE, Flores MT, Garbarino ML. that sensitivity is not a problem. should only be crowned if they needed treatment without incurring significant D ental trauma in children and adolescents a crown regardless of the endodontic in-office charges. Additionally, waiting in Valparaiso, Chile. Endo Dent Traumatol. Inside-Outside therapy. The reason is because the single 2 weeks after bleaching for the shade to 1999;10:223-227. Open Bleaching greatest predictor of survival of an end- stabilize and the bond strengths to re- 17. Cornwell H. Dental trauma due to sport in I n special patients and situations, the odontically treated tooth is the amount turn to normal and then using internal the pediatric patient. Calif Dent Assoc J. 2005; dentist may chose to perform inside and of remaining dentin. If an intact anterior composite bonding can harmonize final 33(6)457-461. outside bleaching while leaving the ac- tooth has a root canal, the external enam- shade discrepancies. Regardless of the 18. Zerman N, Caralleri G. Traumatic injuries cess opening unrestored. In this situa- el and dentin is still intact. Preparing the technique used for bleaching, a relapse to permanent incisors. Endod Dent Traumatol. tion, the patient injects carbamide per- tooth for a crown after the endodontic is possible in 1 to 3 years, and is generally 1993;9:61-64. oxide into the pulp chamber and the tray, treatment removes the remaining den- best addressed by outside bleaching in 19. Skaare AB, Jacabsen I. Etiological factors then seats the tray in the mouth to pro- tin and results in a premature loss of the a single-tooth tray with 10% carbamide related to dental injuries in Norwegians aged tect the opening. While this may shorten tooth. Research has also shown that the peroxide to re-bleach the tooth until it 7-18 years. Dent Traumatol. 2003;19:304-8. treatment time due to the continued ap- post does not strengthen the tooth, and matches the surrounding teeth. 20. Gassner R, Bösch R, Tulit, Emskoff R. plication of fresh bleaching material, it cannot compensate for the loss of dentin. Prevalence of dental trauma in 6000 patients is essential that the patient be able to Hence, the tooth has a better prognosis to References with facial injuries: Implications for treatment. perform their part, and also return to be bleached and restored with composite 1. Glendor U, Halling A, Andersson L, Eilert- Oral Surg Oral Med Oral Path Oral Radiol the office to have the opening closed. than to receive a post, core, and crown. Petersson E. Incidence of traumatic tooth Endod. 1999;87:27-33. While the tooth will not get any tooth injuries in the county of Västmauland, Sweden. 21. Brunner F, Krasti G, Filippi A. Dental trauma decay during the bleaching process due Conclusion Swed Dent J. 1996;20:15-28. in adults in Switzerland. Dent Traumatol. to the increase in pH afforded by the T he single dark tooth is an esthetic 2. Andreasen JO, Andreasen FM, Andersson L. 2009;25:181-184. carbamide peroxide,46 there is the dan- challenge regardless of the treatment Textbook and Color Atlas of Traumatic Injuries 22. Promoting oral health: interventions for ger that the patient may cease bleach- approach. Bleaching the single tooth to the Teeth. 4th ed. Oxford, England: Blackwell preventing dental caries, oral and pharyngeal ing but not return in a timely fashion alone is the safest, most conservative Munskgaard; 2007. cancers and sports related craniofacial injuries: to have the orifice sealed.I f the office is approach to determining the response 3. Davis GT, Knott SC. Dental trauma in a report on recommendations of the Task Force not equipped to fabricate the additional of the single tooth before changing the Australia. Aust Dent J. 1984;29:217-221. on Community Preventive services. MMWR. 4. Brunner F, Krasti G, Filippi A. Dental trauma 2001;50(R R 21):1-13. in adults in Switzerland. Dental Traumatol. 23. Tuli T, Hachl O, Hohlrieder M, et al. 2009;25:181-184. D entofacial trauma in sports accidents. Gen 5. Glendor U. Epidemiology of traumatic dental Dent. 2002;50(3):274-279. injuries—a 12 year review of the literature. Dent 24. Needleman HL. Orofacial trauma in child Traumatol. 2008;24:603-609. abuse: types, prevalence, management and the 6. Kaste LM, Gift HC, Bhat M, Swango PA. dental profession. Pediatr Dent. 1986;8:71-80. Prevalence of incisor trauma in persons 6-50 25. Dimitroulis G, Eyre J. A 7-year review of years of age: United States, 1988-1991. J Dent maxillofacial trauma in a central London hos- Res. 1996;75:696-705. pital. Br Dent J. 1991;170:300-302. 7. Petti S, Tarsitani G, Arcadi P, et al. The preva- 26. Perkeentupa U, Laukkanen P, Veijola J, et al. lence of anterior tooth trauma in children 6 to 11 I ncreased lifetime prevalence of dental trauma f ig. 19 f ig. 20 years old. Minerva Stomatol. 1996;45:213-218. is associated with previous non-dental injuries, 8. Rocha MJ, Cardoso M. Traumatized perma- mental distress and high alcohol consumption. CASE EXAMPLE FOUR ((19.) The endodontically treated canine is much darker than the adjacent teeth, but in this less-esthetic area, a full tray was nent teeth in Brazilian children at the Federal Dent Traumatol. 2001;17:10-16. used to lighten all the teeth. The canine was bleached internally with one University of Santa Catarina, Brazil. Dent 27. Feiglin B. Dental pulp response to traumatic treatment and externally to completion. (20.) After 3 weeks of external Traumatol. 2001;17:245-249. injuries—a retrospective analysis with case bleaching with 10% carbamide peroxide at night, the adjacent teeth reached their maximum lightness. While the other teeth are slightly lighter than the 9. Flores MT. Traumatic injuries in the primary reports. Endod Dent Traumatol. 1996;12:1-8. canine, the color match was much closer and pleasing to the patient. dentition. Dent Traumatol. 2002;18:287-298. 28. Amir FA, Gutmann JL, Witherspoon DE.

50 inside dentistry | S eptember 2010 | insidedentistry.net Considerations for Managing Bleaching Sensitivity

Tooth sensitivity is the single most significant deterrent to cacy of hydrogen peroxide (30 to 60 minutes), they still bleaching, and must be understood to be able to manage the generate tooth sensitivity as well as gingival irritation. Even treatment of patients. All forms of vital tooth bleaching are shorter treatment times of OTC strips with higher concen- associated with some level of sensitivity.1-6 Hence, the den- trations have exhibited greater sensitivity than lower con- tal office and the patient must be prepared for the possibili- centrations with longer treatment times.13 ty of sensitivity during bleaching treatment. The classic tray bleaching treatment involves 10% car- bamide peroxide or 3.5% hydrogen peroxide. Incidences of PREVALENCE AND CAUSE 25% to 75% are reported,14,15 although differences in study design influence data in all treatment options. Generally, The three major classes of bleaching—in-office, tray, and sensitivity occurs in the first 2 weeks of treatment, often in over-the-counter (OTC)—all demonstrate some prevalence the first few days.16 The more recent addition of potassium of sensitivity. Typical bleaching ingredients are either hydro- nitrate to bleaching materials has reduced, but not eliminat- gen peroxide or carbamide peroxide. For comparison, a 10% ed, sensitivity. It is important to note that the presence of carbamide peroxide product is approximately 3.5% hydro- sensitivity is the most probable cause for persons discontin- gen peroxide. Generally, the higher the concentration of the uing bleaching, with one report of 14% termination of peroxide, the greater the chance of sensitivity.7 In-office bleaching due to sensitivity.17 bleaching uses the highest concentration of peroxide (15% A recent report on double-blinded, placebo-controlled to 35% hydrogen peroxide), and has a range of sensitivity clinical trials has provided evidence that the addition of low from 10% to 90%, with some sensitivity being so severe as to levels of potassium nitrate and/or potassium nitrate and flu- require analgesics posttreatment.8-10 Typically, multiple in- oride significantly reduce postoperative sensitivity relative to office visits are required for maximum whitening,11 and those products that do not contain either agent.3,5 visits should be spaced at least 1 week apart to allow for Whereas all of the typical causes of dentin hypersensitiv- reduction of sensitivity ity generally involve caused by treatment.12 the hydrodynamic the- It is also recommend- ory of fluid flow, the ed to pre-medicate pa- sensitivity associated tients with non-steroid with bleaching seems anti-inflammatory to have a different ori- drugs to reduce the in- gin. In bleaching situ- cidence of sensitivity.12 ations, the teeth may The second highest be in excellent condi- concentration of per- tion, with no cracks, ex- oxide is found in the posed dentin, or deep OTC products. These restorations, but after products typically range a few days of bleaching, from 6% to 15% hy- the tooth may experi- drogen peroxide. Al- ence severe sensitivity. though they have a This seems to be relat- shorter treatment time Figure 1 Tray application of a potassium nitrate-containing desensitizing ed to the easy passage due to the limited effi- material is a very effective approach to treatment of sensitivity. of hydrogen peroxide

25 Figure 2 Bleaching Sensitivity Treatment: Stage 1 Prevention options in patients with existing sensitive teeth. and urea through the intact enamel, through the dentin in ing is very individualistic, and can only be determined by the interstitial spaces into the pulp within 5 to 15 minutes.18 beginning treatment. However, the history of sensitive teeth In effect, the tooth is a semipermeable membrane that is by the patient, as well as their response during examination quite open to certain-sized molecules. Once it is understood to explorer touch or air, can be a reasonable predictor. how easily the peroxide penetrates the tooth, the resultant Because bleaching tends to produce some tooth sensitiv- pulpal response of sensitivity may be considered a reversible ity under ordinary circumstances, patients with pre-existing pulpitis. Tooth sensitivity is the main side effect of bleach- tooth sensitivity must be cautioned that increased sensitivi- ing, and may be caused primarily by the peroxide penetra- ty, albeit transitory, may occur, and that management of the tion to the pulp, and secondarily by the mechanical pressure sensitivity may require a longer time span for bleaching as a of an improperly fitting tray or occlusion on the tray. The result of the additional time to treat the sensitivity. other side effect recorded is gingival irritation, which may Other contributors to sensitivity include rigid tray mate- be related to an improperly fitted tray, occlusion on the tray, rials, the base vehicle composition and viscosity, flavoring or chemical irritation from higher concentrations of hydro- agents, or patient habits such as clenching or bruxism. The gen or carbamide peroxide. short-term pulpal response varies from patient to patient and even from tooth to tooth. Although penetration of per- PREVENTION oxide through the tooth to the pulp can produce sensitivity, the pulp remains healthy and the sensitivity is completely Because tooth sensitivity mainly depends on inherent patient reversible when treatment is terminated. No long-term sensitivity, frequency of application, and concentration of sequelae remain after the sensitivity has abated.23-25 Research the material, a history of sensitivity should be determined also has shown that patients have tooth sensitivity even during the examination.14,19 Patients generally will report when using a non-bleaching agent in a tray, or just wearing or should be asked if their teeth are sensitive to cold. Ad- a tray alone. Hence, it is not possible to have all patients be ditionally, existing sensitivity can be determined from the sensitivity-free because of the mechanical forces of materials preoperative exam by simple methods of explorer contact and occlusion, and some plans must be made to address with areas on the teeth, or air blown on the teeth. Patients potential problems. can be counseled in the frequency of application and the appropriate concentration of bleaching agent, with instruc- TREATMENT tions that applications more than once a day or higher con- RECOMMENDATIONS centrations of bleaching agent increase the likelihood of sensitivity.3,4,20-22 All other delineators, such as pulp size, Most of the earlier treatments for sensitivity involved tray exposed dentin, cracks, gingival recession, caries, sex or age bleaching, as the ease of use of this system and universal of the patient, or other physical characteristics are not pre- popularity made it the most commonly used system for dictive of who would have sensitivity. tooth bleaching.26,27 The passive approach for treating sen- Most reports of sensitivity occur within the first 2 weeks, sitivity was first used. This involved a reduction in wear regardless of how long the patient may treat their teeth. time, or in frequency of application. Sensitivity treatment Often, these reports are a single day of sensitivity, followed could also involve temporary interruption of the bleaching by no problems the next day. The tooth’s response to bleach- treatment. After the interruption, treatment can often be

A recent report on double-blinded, placebo-controlled clinical trials has provided evidence that the addition of low levels of potassium nitrate and/or potassium nitrate and fluoride significantly reduce postoperative sensitivity relative to products that do not contain either agent.

27 Figure 3 Bleaching Sensitivity Treatment: Stage 2 Treatment options for patients who experience sensitive teeth during bleaching. resumed without any fur- need it with tray applica- ther sensitivity. Cessation tion, even before a prophyl- of treatment results in no axis. This approach was lingering sensitivity. Al- extended by Haywood to though the passive approach include patients experienc- has some success, patients ing sensitivity during bleach- and dentists prefer to have ing.28 Tray application could a more active approach. The be used either before or active approach involves after the bleaching treat- the use of either fluoride, ment (Figure 1). Because potassium nitrate, or both the pain can occur remote- in combination. Tradition- ly from the bleaching treat- ally, fluoride has been used ment, the potassium nitrate as a method of reducing could be used as needed sensitivity. The primary during the day or night. In mechanism for action is to severe situations, the po- occlude dentinal tubules or tassium nitrate could be increase the hardness of substituted for the bleach- enamel, which impedes the ing material on alternating flow of materials to the nights of wear. pulp. However, the perox- Figure 4 The three options for avoidance or treatment of - The more readily avail- ide molecule is so small bleaching sensitivity involve the application of potassium able source of 5% potassi- that it can travel in the in- nitrate products either in the bleaching tray or topically. um nitrate in the United terstitial spaces between the States is desensitizing tooth- dentinal tubules. Hence, fluoride has not been particularly pastes that contain 5% potassium nitrate. Five percent is the beneficial in treating bleaching sensitivity. maximum amount of potassium nitrate approved by the US Food and Drug Administration, and is the primary ingredi- Potassium Nitrate Use in Bleaching ent for sensitivity treatment allowed in OTC toothpaste. Potassium nitrate has a completely different mechanism of Based on the tray application study, desensitizing toothpaste action than fluoride. Potassium nitrate penetrates the enam- can be placed in the tray for 10 to 30 minutes whenever sen- el and dentin to travel to the pulp and creates a calming sitivity occurs. The only caution with toothpaste application effect on the nerve by affecting the transmission of nerve is that some patients may experience a gingival reaction to impulses. After the nerve depolarizes in the pain stimulus- the foaming ingredient sodium lauryl sulfate. This reaction is response, it cannot re-polarize, so the excitability of the nerve not caused by the potassium nitrate. The reaction generally is reduced. Potassium nitrate almost has an “anesthetic-like produces a tissue burn or reddening of the gingiva. If this effect” on the nerve. irritation occurs with one brand or flavor of toothpaste, the One study demonstrated that applying potassium nitrate clinician may have to experiment with various OTC formu- for 10 to 30 minutes in a bleaching tray could be successful lations for certain patients. Initially there was only one in reducing sensitivity in more than 90% of the patients, toothpaste available which had potassium nitrate, but not and allow them to complete the bleaching procedure suc- sodium laural sulfate, and that was the original “Pink pack- cessfully.28 This technique was originally used by Jerome to aged” Sensodyne. More recently, the advent of “Pronamel treat tooth sensitivity after periodontal surgery in non- Sensodyne” has provided a new option for a non-sodium bleaching patients.29 He placed desensitizing toothpaste laural sulfate, potassium-nitrate containing toothpaste to be into soft trays that covered the now-exposed root surfaces of used in brushing or in the tray for treatment of sensitivity. the teeth, and achieved good results. For patients with If suitable toothpaste cannot be found for the patient, then chronic sensitivity unrelated to bleaching, the toothpaste the clinician should use the professionally available products gives them an OTC product that they can use whenever they containing 3% to 5% potassium nitrate and fluoride.

29 Several companies provide 3% to 5% potassium nitrate in a Recommended Treatment syringe for application in the bleaching tray as needed. The Bleaching sensitivity may result from a combination of the syringe materials, which must be purchased from the compa- patient’s pre-existing tooth and gingival conditions, the nies, may be more appropriate for episodic sensitivity associated chemical nature of the peroxide, and the mechanical nature with the bleaching itself where the toothpaste was not accept- of the tray. The dentist should determine if the patient has able because of the gingival response. There are also disposable pre-existing sensitive teeth that require a protocol to mini- trays containing potassium nitrate which may be helpful, especially mize sensitivity during bleaching. If the patient has no pre- if there is no bleaching tray available for in-office techniques existing sensitivity, a proactive protocol should be developed being used alone. to address sensitivity should it occur. Figure 2 and Figure 3 Once research determined that potassium nitrate in the offer this information in two treatment options, one for tray was successful, the next step was to incorporate this patients with a history of sensitivity, and one for patients material in the bleaching material rather than require a sep- with no pre-existing sensitivity. They also explain the options arate application. First attempts were not too chemically for passive or active treatment of sensitivity that occurs once successful, but now most manufacturers have their bleach- the bleaching process is initiated. ing product containing both fluoride and potassium nitrate. Examples of this would be Opalescence PF (Ultradent CONCLUSION Products, Inc, South Jordan, UT), NiteWhite® Excel and NiteWhite® ACP (Discus Dental, Culver City, CA), Contra- Treatment of bleaching sensitivity involves many possible stpm® (Spectrum Dental, Corpus Christi, TX) , GC TiON™ options (Figure 4). Prebrushing with a potassium nitrate- (GC America), and Opalescence® Treswhite™ Supreme containing toothpaste can reduce or avoid sensitivity from (Ultradent Products). Early concerns were that either the bleaching. Tray application of potassium nitrate can be an fluoride or the potassium nitrate would interfere with the effective episodic treatment for sensitivity.Other treat- bleaching, but one study has indicated that bleaching effica- ment time variations, use of different concentrations of cy is not reduced.30 Certainly, if there is any reduction in material, and varying tray designs can all be part of a sen- efficacy or increase in time of treatment, it is minor, and sitivity management program. It is far better to try to much better than termination of bleaching resulting from avoid or minimize the sensitivity with the above steps than unmanageable sensitivity.31 Having the potassium nitrate in to treat sensitivity after it occurs. Even with all these the material could also minimize the effects of mechanical options for sensitivity avoidance and treatment, there are irritation from an improperly fitting tray or occlusion caus- still some patients who cannot manage their sensitivity ing movement of the tray and resultant tooth sensitivity.5 and elect to terminate bleaching. Sensitivity seems to be a multi-factorial event which cannot be entirely controlled Pre-Brushing with Potassium Nitrate in every patient. However, the majority of patients, after a for Sensitivity Avoidance proper dental examination, history, and radiographs, can Even though tray application of potassium nitrate was very find an appropriate method with adjustment of treatment effective, and the incorporation of potassium nitrate into the time and material, brushing with a desensitizing tooth- bleaching material has helped, these advances do not totally paste containing potassium nitrate, or tray application of eliminate sensitivity. Relief from sensitivity requires brushing potassium nitrate, to minimize any sensitivity they may with potassium nitrate for approximately 2 weeks to be effec- encounter, and proceed to a successful completion of the tive.32 A recent study33 compared patients who pre-brushed bleaching process. with the toothpaste containing potassium nitrate (Sensodyne) for 2 weeks before initiating bleaching to another group that REFERENCES used conventional fluoride-containing toothpaste. The group that pre-brushed with the potassium nitrate-containing tooth- 1. Auschill TM, Hellwig E, Schmidate S, et al. Efficacy, side-effects paste had less sensitivity overall, less sensitivity in the first 3 days, and patients’ acceptance of different bleaching techniques (OTC, and more sensitivity-free days before a first occurrence. Results in-office, at-home). Oper Dent. 2005;30(2):155-163. of patient surveys showed that the switch to a potassium nitrate- 2. Leonard RH, Bentley C, Eagle JC, et al. Nightguard vital containing toothpaste was easy and well-accepted. bleaching: A long-term study of efficacy, shade retention, side

30 effects, and patients’ perceptions. J Esthet Restor Dent. 2001; 1994;125(10):1330-1335. 13(6):357-369. 18.Cooper JS, Bokmeyer TJ, Bowles WH. Penetration of the pulp 3. Browning WD, Blalock JS, Frazier KB, et al. Duration and chamber by carbamide peroxide bleaching agents. J Endod. timing of sensitivity related to bleaching. J Esthet Restor Dent. 1992;18:315-317. 2007;19(5):256-264. 19.Leonard RH, Haywood VB, Phillips C. Risk factors for devel- 4. Browning WD, Swift EJ. Critical appraisal: Comparison of the oping tooth sensitivity and gingival irritation associated with effectiveness and safety of carbamide peroxide whitening agents nightguard vital bleaching. Quintessence Int. 1997;28:527-534. at different concentrations. J Esthet Restor Dent. 2007;19 20.Kihn P, Barnes DM, Romberg E, Peterson K. A clinical evalua- (5):289-296. tion of 10 percent VS 15 percent carbamide peroxide tooth- 5. Browning WD, Chan DC, Myers ML, et al. Comparison of whitening agent. J Am Dent Assoc. 2000;131:1478-1484. traditional and low sensitivity whiteners. Oper Dent. 2008; 21.Krause F, Soren J, Braun A. Subjective intensities of pain and 33(4):379-385. contentment with treatment outcomes during tray bleaching of 6. Leonard RH, Smith LR, Garland GE, et al. Evaluation of side vital teeth employing different carbamide peroxide concentra- effects and patients’ perceptions during tooth bleaching. Esthet tions. Quintessence Int. 2008;39:203-209. Restor Dent. 2007;19(6):355-366. 22.Matis BA, Mousa HN, Cochran MA, Eckert GJ. Clinical eval- 7. Browning WD, Swift EJ. Critical Appraisal: Comparison of uation of bleaching agents of different concentrations. the effectiveness and safety of carbamide peroxide whitening Quintessence Int. 2000;31(5):303-310. agents at different concentrations. J Esthet Restor Dent. 2007; 23.Pohjola RM, Browning WD, Hackman ST, et al. Sensitivity and 19(5):289-296. tooth whitening agents. J Esthet Restor Dent. 2002;14:85-91. 8. Paparthanasiou A, Bardwell D, Kugel G. A clinical study eval- 24.Ritter AV, Leonard RH, St Georges AJ, et al. Safety and stabil- uating a new chairside and take-home whitening ssystem. ity of nightguard vital bleaching: 9 to 12 years post-treatment. Compendium. 2001;22(4):289-298. J Esthet Restor Dent. 2002;14(5):275-285. 9. Lu AC, Margiotta A, Nathoo SA. In-office tooth whitening: 25.Swift EJ. Critical appraisal: At-home bleaching: pulpal effects current procedures. Compendium. 2001;22(9):798-805. and tooth sensitivity Issues. Part 1. J Esthet Restor Dent. 2006; 10.Kugel G, Papathasiou A, Williams AJ, et al. Clinical evaluation 18(4):225-228. of chemical and light-activated tooth whitening systems. 26.Haywood VB. Dentine hypersensitivity: bleaching and restora- Compendium. 2006;27(1):54-62. tive considerations for successful management. Int Dent J. 11.Gottardi MS, Brackett MG, Haywood VB. Number of in- 2002,52(5 Supp1):376-384. office light-activated bleaching treatments needed to achieve 27.Haywood VB. Treating sensitivity during tooth whitening. patient satisfaction. Quintessence Int. 2006;37(2):115-120. Compend Cont Educ Dent. 2006;26(9):11-20. 12.Goldstein CE, Goldstein RE, Feinman RA, Garber DA. Bleaching 28.Haywood VB, Caughman WF, Frazier KB, et al. Tray delivery vital teeth: state of the art. Quintessence Int. 1989;20(10);729-737. of potassium nitrate fluoride to reduce bleaching sensitivity. 13.Gerlach RW,Sagel PA.Vital bleaching with a thin peroxide gel: Quintessence Int. 2001;32:105-109. The safety and efficacy of a professional-strength hydrogen per- 29.Jerome CE. Acute care for unusual cased of dentinal hypersen- oxide whitening strip. J Am Dent Assoc. 2004;135(1):98-100. sitivity. Quintessence Int. 1995;26:715-716. 14.Haywood VB, Leonard R, Nelson CF, et al. Effectiveness, side 30.Tam L. Effect of potassium nitrate and fluoride on carbamide effects and long-term status of nightguard vital bleaching. J Am peroxide bleaching. Quintessence Int. 2001;32:766. Dent Assoc. 1994;125(9):1219-1226. 31.Leonard RH, Smith LR, Garland GE, Caplan DJ. Densensitizing 15.Haywood VB. Dentine hypersensitivity: bleaching and restora- agent efficacy during whitening in an at-risk population. J tive considerations for successful management. Int Dent J. Esthet Restor Dent. 2004;16:49-56. 2002:52(5 suppl 1):376-384 32.Silverman G, Berman E, Hanna CB, et al. Assessing the effica- 16.Jorgensen MG, Carroll WB. Incidence of tooth sensitivity after cy of three dentifrices in the treatment of dentinal hypersensi- home whitening treatment. J Am Dent Assoc. 2002;133(8): tivity. J Am Dent Assoc. 1996;127:191-201. 1076-1082. 33.Haywood VB, Cordero F, Wright K, et al. Brushing with potas- 17.Schulte JR, Morrissette D B, Gasior E J, et al. The effects of sium nitrate dentifrice to reduce bleaching sensitivity. J Clin bleaching application time on the dental pulp. J Am Dent Assoc Dent. 2005:16(1):17-22.

31 Clinical Bleaching and caries control in elderly patients

Professor Van B. Haywood DMD examines the role of bleaching in the older patient and how it relates to caries

leaching teeth with carbamide perox- ide in a custom tray is an exciting serv- Bice to offer patients and a tremendous adjunct to restorative dental treatment. One of the side effects noticed when bleaching teeth is that the use of 10% carbamide peroxide ap- plied nightly in a custom-fitted tray is effective to remove plaque, reduce caries bacteria and elevate pH on elderly patients for successful long-term oral hygiene care. As the population of the world ages and is living longer with more teeth, there is a greater number of people who have received good dental care in their younger years, but are now faced with difficulty in maintaining those restorations and existing teeth in their later years. Dentists have experienced the frus- tration of rampart root surface caries around crown margins or in virgin teeth as these pa- tients age. This caries phenomenon seems to be associated with a reduction in salivary flow, due to both ageing, increased side effects of medications, and decline in health. There is also a loss in manual dexterity, and the abil- ity to perform routine oral hygiene care. Even if these patients have access to care from a general dentist, their ability to clean at home around hemi-sected molars, under pontics for Fixed Partical Dentures, or interproximally around gingival recession or periodontally involved teeth is compromised, and often re- sults in caries between dental appointments.

42 Aesthetic dentistry today October 2007 Volume 1 Number 4 Clinical

Moderate tetracycline stained teeth with dark Four month of nightly bleaching using at 10% A non-scalloped, no-reservoir bleaching tray is used discoloration on the incisal half and slight banding carbamide peroxide in a non-scalloped, no-reservoir to apply 10% carbamide peroxide nightly for caries is an unsightly problem for this patient. Tetracycline- tray produces an acceptable outcome. Now the patient control in elderly patients. One or both arches may stained teeth generally take two to six months to is interested in restoring the fractured central incisor. be treated, depending on the patient’s needs. The treat. Generally lighter teeth make a person appear 10 One arch was treated at a time to allow compari- disadvantage is the natural teeth will become whiter years younger son and encourage compliance. Elderly people look but restorations will not change colour younger with whiter teeth

This mechanical disadvantage is further com- ies, two hours). This occurrence is related to orthodontic patients during three years treat- plicated by the tendency of these patients to the urea in the composition (Firestone et al, ment to prevent white spot lesions (Fogel and use sugar containing mints for breath due to 1982, Wainwright and Lemoine, 1950). The Magill, 1971). It has also been used in elderly salivary flow loss, and the resultant effect on pH values are crucial to preventing the forma- patients as a rinse for oral hygiene (Haywood, the caries index. tion of tooth decay, since root caries can start 1992). Carbamide peroxide seems to be most What is needed is a simple, inexpen- when the pH of the mouth is between 6 and effective when some type of container or bar- sive mechanism to apply to better clean the 6.8 (Hoppenbrouwers et al, 1986, 1987). A rier is used. teeth. Rather than mechanical means alone, further study has indicated that 10%CP kills The questions of safety to the ingestion have a chemotherapeutic approach is needed. one of the two bacteria causing tooth de- been answered in literature prior to bleach- Typically, fluoride in a tray has been used for cay (Bentley et al, 2000). Gingival indices in ing, as well as current literature (Ritter et al, this population. However, clinical experi- bleaching studies have indicated some im- 2002, European Commission, 2005). Prior to ence has indicated this is not very effective. provement in gingival scores (Powell and bleaching and even today, 10% carbamide per- Chlorohexidine is also used, but the staining is Bales, 1991), although the patient population oxide is used in new born infants, 10 drops in a detriment to use. Interestingly enough, 10% involved in bleaching often has a very clean their throat every two hours for seven to eight carbamide peroxide can be used alternately mouth for the onset of treatment. Carbamide days, to treat candidiasis or thrush (Dickstein, with Chlorohexidine to remove those stains peroxide is preferred rather than hydrogen 1964). (Addy et al, 1991). peroxide, since the urea and carbopol in 10% Since carbamide peroxide kills lactobacil- Although 10% carbamide peroxide is gen- CP allows it to be active up to 10 hours in the lus, and Chloroxidine kills strep mutans, one erally associated with tooth whitening, the ma- mouth, while hydrogen peroxide is only active option is to both clean the teeth and destroy terial was originally used as an oral antiseptic for 30-60 minutes. (Haywood, 2007). the lactobacillus bacteria by wearing the non- for gingival healing (Haywood, 1992). It was The tray design used for caries control is a scalloped, no-reservoir tray overnight with being applied in a tray for wound healing non-scalloped, no reservoir tray, which extends 10% carbamide peroxide. This can be supple- when the tooth whitening side effect was dis- 1-2mm onto the gingival tissue (Haywood mented by using Cholohexidine rinse for 30 covered (Haywood, 1991). Carbamide perox- 2006, 2007). It should not extend into un- seconds prior to bedtime. In addition to caries ide 10 and 15% has been has been classified by dercuts to the path of insertion, nor encroach control, the 10%CP can control the staining the United States Food and Drug Association on frenum attachments. The contact with the from Chlorohexidine. as category 1, which means there are suf- gingival prevents the washing out of the ma- The only side effect of this treatment is that ficient data to demonstrate that these agents terial, and does not generally cause gingival the teeth will become white. For most people, are safe and effective for use in the oral cav- irritation at the 10% concentration (Leonard this may be a benefit. However, since resto- ity as oral antiseptic agents (Haywood, 1993, et al, 1994). The lack of reservoirs means less rations do not change colour, there can be a Dental Product Spotlight, 2001). Persons now material is needed per application. The tradi- mismatch between existing restorations and involved in tooth whitening research report a tional custom fitted bleaching tray from an al- bleached teeth. Some restorations may need loss of plaque during that time such that their ginate impression works well, although there to be replaced due to this colour mismatch. teeth feel ‘squeaky clean’ much like after a are some options with ‘boil and form’ trays in However, the benefit of saving the teeth, or prophylaxsis. Reports from a century ago cite certain arches (Haywood et al, 2001). The boil having larger restorations due to caries may the use of this material in children with pitted and form tray can also be used as a diagnostic override this concern. Teeth typically whiten to teeth to reduce caries (Atkinson, 1893). test to see if the patient can wear the tray and a certain level, then stabilise, even with further Current research on safety noted that the if the material will be effective. treatment. However, it is unknown to what pH of the saliva and the material in the tray is Carbamide peroxide for caries control has level of whitening the patient will progress, so elevated to about eight in less than five minutes a long history of use, except that the previous some patients may have very white teeth over after application, and remains that for the du- attempts did not employ a tray application. time. ration of the application (Leonard et al, 1994, Several papers cite the use of 10% carbamide Sensitivity is often associated with bleach- Leonard and Austin et al, 1994) (in those stud- peroxide as a rinse, in the form of Glyoxide, in ing. However, in elderly patients, the pulps

October 2007 Volume 1 Number 4 Aesthetic dentistry today 43 Clinical

have receded such that sensitivity is seldom bleaching. Current Opinion in Cosmetic a problem. The use of potassium nitrate in Dentistry 1993:12-18. the bleaching tray for 10-30 minutes has Haywood V B. Considerations for Vital been shown to alleviate this in most patients Nightguard Tooth Bleaching with 10% (Haywood et al, 2001). Additionally, many Carbamide Peroxide after nearly 20 Years of bleaching products now contain this ingredi- Proven Use. Inside Dentistry 2006; Sept: 2-5. ent, and sensitivity levels have been greatly Haywood V B. Extended Bleaching of reduced with the combination of potassium Tetracycline-stained teeth: a case report. nitrate and a soft tray, as well as by pre-brush- Contemporary Esthetics and Restorative ing and using a desensitising toothpaste dur- Practice 1997;1(1):14-21. ing treatment (Haywood et al, 2005). Haywood V B. History, safety, and effectiveness This technique is meant to be used for the of current bleaching techniques and applica- life of the patient. Studies on bleaching teeth tions of the nightguard vital bleaching tech- nightly for six to twelve months with tetracy- nique. Quintessence Int 1992;23:471-488. cline-stained teeth have indicated no harm to Haywood V B. Treating Sensitivity during Tooth the teeth or pulp with low concentrations of Whitening. Compendium 2006;26(9):11-20. carbamide peroxide (Haywood 1997, Matis et Home-Use Bleaching Agents. Dental Product al 2006, Leonard et al 1994). Spotlight. JADA 2001;132:1292. Additionally, this technique may prove ben- Haywood VB.Tooth Whitening: Indications eficial with oral cancer patients for whom the and Outcomes of Nightguard Vital Bleaching. cancer treatment has reduced the salivary flow, Quintessence Pulbishing Co, Inc. Hanover and caries is a problem. It is also used in or- Park, IL 2007:133-138 thodontic patients to avoid white spot lesions, Hoppenbrouwers PMM, Driessens FCM, although the fit of the tray and the amount of Clinical Pediatrics 1964;3(8):485-488. Borggreven JMPM. The Mineral Solubility material needed makes this option more of a European Commission:Scientific Committee of Human Tooth Roots. Archs Oral Biol. challenge. Typically the ‘boil and form’ trays on Consumer Products: March 2005 1987;32:319-322. can be made over the brackets if care is taken. SCCP/0844/04 (website). Hoppenbrouwers PMM, Driessens FCM, Firestone A R, Schmid R, Muhlemann H R. Borggreven JMPM: The vulnerability of unex- Summary Effect of topical application of urea peroxide posed human dental roots to demineralization. Root caries may be minimised by use of car- on caries incidence and plaque accumulation J Dent Res 65(7):955-958, 1986 bamide peroxide in a tray overnight to re- in rats. Caries Res 1982;16:112-117. Leonard R H Jr, Bentley C D, Haywood V B. move plaque, elevate pH and kill bacteria. Fogel M S, and Magill J M. Use of an Antiseptic Salivary pH changes during 10% carbamide Long-term use is both cost efficient and safe. Agent in Orthodontic Hygiene. Dental Survey peroxide bleaching. Quintessence Int 1994 Sensitivity can be treated by potassium nitrate 1971; October:50-54. 25: 547–550. in the tray, pre-brushing with it, and using a Haywood V B. History, safety, and effectiveness Leonard RH, Austin SM, Haywood VB, and bleaching product containing the material. of current bleaching techniques and applica- Bentley CD. Change in pH of plaque and 10% Primarily the indication for caries control is for tions of the nightguard vital bleaching tech- carbamide peroxide solution during night- ageing patients, those with physical handicaps nique. Quintessence Int 1992 23: 471–488. guard vital bleaching treatment. Quintessence or patients in nursing homes for which con- Haywood V B., Caughman W F, Frazier K B, Int., 1994 Dec; 25(12): 819-23. ventional brushing and flossing is not prov- Myers M L. Tray delivery of Potassium ni- Leonard RH, Haywood VB, Caplan DJ, Tart ND. ing effective. The side effect of whitening the trate-fluoride to reduce bleaching sensitivity. Nightguard Vital Bleaching of Tetracycline- teeth is often less of a problem than the cost Quintessence Int 2001;32:105-9. Stained teeth: 90 months Post Treatment. J and medical challenge of restoring teeth due Haywood V B, Caughman W F, Frazier K B, Myers Esthet Restor Dent 2003;15(3):142-154. to root caries. M L. Fabrication of Immediate Thermoplastic Matis BA, Wang Y, Eckert GJ, Cochran MA, Whitening Trays. Contemporary Esthetics and Jiang T. Extended bleaching of tetracycline- References Restorative Practice 2001;5(9):84-86. stained teeth: A 5-year study.Operative Dent, Addy M, al-Arrayed F, Moran J. The use of an Haywood V B, Cordero R, Wright K, Gendreau 2006, 31-6, 643-651. oxidising mouthwash to reduce staining asso- L, Rupp R, Kotler M, Littlejohn S, Fabyanski Powell LV, Bales DJ. Tooth bleaching: its ciated with chlorhexidine. Studies in vitro and J, Smith S. Brushing with a potassium nitrate effect on oral tissues. J Am Dent Assoc in vivo. J Clin Periodontol 1991;18(4):267- dentifrice to reduce bleaching sensitivity.J Clin 1991;122(12):50-4. 71. Dent. 2005;16(1):17-22. Ritter AV, Leonard RH, St. Georges AJ, Caplan Atkinson CB. Hints, Queries, and Comments: Haywood V B, Leonard RH, Dickinson GL. DJ, Haywood VB. Safety and stability of night- Pyrozone. The Dental Cosmos 1893;35:330- Efficacy of six-months nightguard vital bleach- guard vital bleaching: 9 to 12 years post-treat- 332. ing of tetracycline-stained teeth. J Esthet Dent ment. J Esthet Restor Dent 2002; 14(5):275- Bentley CD, Leonard RH Jr and Crawford J. 1997;9(1):13-19. 285. Effects of whitening agents containing car- Haywood V B. Nightguard Vital Bleaching: A Wainwright WW, Lemoine FA: Rapid diffuse bamide peroxide on cariogenic bacteria. J History and Products Update: Part 1. Esthetic penetration of intact enamel and dentin by Esthet Dent 2000; 12: 33-37. Dentistry Update 1991;2(4):63-66. carbon14-labeled urea. JADA 1950;41:135- Dickstein B. Neonatal Oral Candidiasis: Haywood V B. The Food and Drug 145. Evaluation of a new chemotherapeutic agent. Administration and its influence on home A

43 Aesthetic dentistry today October 2007 Volume 1 Number 4 continuing Education Inside ESTHETICS

Orthodontic Caries Control This lesson was underwritten by: and Bleaching Learning Objectives Custom tray application of 10% carbamide peroxide to orthodontic patients for removal of • understand how the pH effects of carbam- plaque and avoidance of white-spot lesions is outlined. ide peroxide bleaching materials affects the caries process and oral hygiene. By Van B. Haywood, DMD in the traditional method using an alg- • learn a technique for fabrication of inate impression and vacuum-formed thermoplastic bleaching trays over orth- matrix was determined to work better. odontic brackets directly in the mouth. However, over the course of the 1 to 3 • develop a reasonable treatment option Abstract years of orthodontic treatment, this for caries-risk orthodontic patients to Oral hygiene during orthodontic treatment can be facilitated by applying bleaching mate- approach would involve multiple im- avoid white-spot lesions and caries. rials to elevate the pH of the mouth during the course of treatment. Fabrication of thermo- pressions and trays as the teeth move plastic bleaching trays directly in the mouth over the braces without impressions affords every few months such that the previ- a reasonable technique for the multiple trays required during the orthodontic changes. Log on to www.insidedentistryCE.com ous tray would no longer fit the arch. to take the FREE CE quiz. Also, the main OTC ingredient with the best physical properties (Proxigel, rthodontic treat- to inadequate cleaning of the appliances GlaxoSmithKline Consumer Health to create custom-fitted trays that can ment is one of the during the 1- to 3-year treatment period Care, www.gsk.com) was removed from be worn overnight and contain a cost- most conservative, (Figure 1). Some home care of orthodon- the market, leaving less desirable prod- effective carbamide peroxide and can long-lasting treat- tic patients, especially teenagers, has ucts available for this situation. be used for the duration of the orth- ments to improve been so obviously poor that the ortho- More recently, disposable trays with odontic treatment to clean the braces the esthetics and dontist has found it necessary to remove hydrogen peroxide to be worn for 30 of plaque and avoid white-spot lesions function of a pa- the braces before the completion of to 60 minutes have been introduced post-treatment. The purpose of this tient. Bleaching is also one of the most treatment to save the teeth from decay. as a cost-effective proposal for in-of- article is to present a technique that Oconservative treatments to change the The challenge of orthodontic treatment fice debridement of the braces before addresses those concerns by combin- color of the patient’s teeth. Together, or- is to maintain the cleanliness of the the orthodontic visit. However, these ing information from several sources thodontics and bleaching afford some of braces throughout the treatment phase. trays do not fit well, and the nature of in the bleaching literature with clinical the most conservative, long-lasting treat- While bleaching will whiten teeth, hydrogen peroxide does not retain its applications. ment to offer a patient. Often, bleaching tray bleaching with 10% carbamide activity long enough to be beneficial in may follow orthodontic treatment, and peroxide has the side effect of remov- the caries control process, nor does the Tray Fabrication occasionally use the orthodontic posi- ing plaque from teeth, improving gingi- pH become elevated above that point The traditional method for tray fabrica- tioner as the tray with which to deliver val scores, and elevating the pH of the at which tooth decay can occur. What tion in the tray bleaching process in- the bleaching material. The most popu- mouth and tray.2-8 Carbamide peroxide is needed is a cost-effective method volves a well-made alginate impression lar form for tray bleaching of the teeth has been shown to kill many of the bac- involves the use of 10% carbamide per- teria that cause tooth decay, as well as oxide in a custom-fitted tray.1 remove surface staining. This beneficial One of the most disappointing seque­ side effect affords a practical option to lae of orthodontic treatment may occur deal with the problems of oral hygiene after the appliances are removed. Some­ during orthodontic treatment. times, white-spot lesions are present due There have been many attempts to combine the properties of bleaching with the challenge of cleaning orthodon- Van B. Haywood, DMD tic patients. In the early 1960s, carbam- Professor ide peroxide that was available over-the- Director of Dental counter (OTC) was used as a mouthwash Continuing Education in orthodontic patients for this reason, Department of Oral but with limited success, possibly due Rehabilitation fig. 1 School of Dentistry to the low contact time. When tradi- Medical College of Georgia tional nightguard vital bleaching was CLINICAL EXAMPLE (1.) Poor oral hygiene during orthodontic treatment Augusta, Georgia introduced in the late 1980s, fabrication can result in decalcified and carious enamel at the end of treatment. of a custom-fitted tray over the brackets (Photograph courtesy of Dr. Andrew Kious.)

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of the arch to be bleached. A stone cast is generated from this impression, and trimmed in such a manner as to work well in the vacuum former. The custom-fitted tray is formed from thin soft material. When considering how to clean orth- odontic braces using bleaching tray materials, the main missing portion of the oral hygiene puzzle has been a cost- fig. 2 fig. 5 fig. 8 effective tray fabrication technique that could be used multiple times during treatment. While the traditional alginate impression over the brackets was initial- ly used, it was very difficult to obtain a good impression especially of the area of the teeth between the brackets and the gingiva. This area is the most difficult to clean, and yet the tray fits the poorest in this area. Additionally, the time and la- bor costs to remove the wires, make the fig. 3 fig. 6 fig. 9 alginate impression, pour the impression in cast stone, trim the cast, then fabricate a bleaching tray in a vacuum former for the many times this would be needed make that approach weary for the pa- tient and the orthodontist. An alternate method for bleaching normal teeth to the traditional im- pression, cast, and laboratory fabrica- tion of trays is to use a thermoplastic fig. 4 fig. 7 fig. 10 tray formed directly in the mouth. A dual technique has been previously 9 BLEACHING PROCEDURE (2.) The BLEACHING PROCEDURE (5.) In- BLEACHING PROCEDURE (8.) Scis- reported. A later development to this thicker tray seems to work better struct the patient to close onto their sors may be used to both shorten approach was the introduction of a over the orthodontic brackets by back teeth, and create suction with any extended flanges, as well as single clear tray sold directly to den- covering more teeth and shrinking their lips. (6.) When the tray has remove the handle from the ante- less when heated. (3.) The path of completely cooled in the mouth, rior portion. (9.) Once trimmed, the tists (Sure-Fit Ultra-Thin Professional insertion of the tray should be from disengage it from any brackets or patient will have a smooth com- Trays, Oratech, LLC, www.oratech. the facial. Try in the tray with the wire extensions. (7.) Remove the fortable tray for applying the 10% com; Ultra-Thin Dental Trays, Archtek, patient before heating to ensure custom-fitted tray that has been carbamide peroxide that covers a proper path of insertion and full made directly in the mouth over the the anterior brackets, which also Inc, www.archtekinc.com). In this tech- patient understanding of relaxing orthodontic brackets. protects the cheeks and provides nique, the single clear soft tray is heated their lips. (4.) After the softened a comfortable MI occlusion. (10.) and softened in warm water that has tray is seated correctly, quickly A thick 10% carbamide peroxide is apply finger pressure on the facial applied sparingly in the groove area been initially brought to a boil, then ap- and lingual of the tray to adapt to formed by the brackets. plied to the arch and directly contoured the gingival areas, starting from the to the teeth by finger pressure. The pa- midline and proceeding distally. tient then occludes into the softened tray and applies suction to form-fit completely cover the molars. However, the trays are thermoplastic, they do not tray is that the tray should be inserted the tray to the teeth. After the tray has it has been shown that 10% carbamide get soft enough to imbed themselves from a facial direction to avoid the wires cooled, the tray handle is then removed peroxide is effective as a bleaching in the brackets, yet they can be readily and brackets causing the ends to fold and the tray trimmed to fit. The use of agent well beyond the borders of the adapted to the gingival area below the (Figure 3). The water is heated until this tray eliminates the impression tray,10 and one might expect that the brackets, which is the hardest to clean. it almost boils, then the tray is waved stage for patients who may not toler- antimicrobial effects would extend be- The technique for fabrication over in the hot water until the front edge ate impressions (those who might gag yond the tray as well. orthodontic brackets is outlined in the begins to curl. If it continues too long or choke using an alginate impression The recently introduced thermo- accompanying figures. Although the in the water, it will shrink too much to technique), and is useful in locations plastic trays, also called “boil and form” two clear trays mentioned above in the fit over the brackets. If it touches itself, where laboratory equipment like a bleaching trays, were subsequently previous non-orthodontic bleaching it will bond and be useless. Once the model trimmer or vacuum-forming used with orthodontic patients to avoid will work, the 1.5-mm thicker tray (1.5 tray is softened, it is removed and the machine is not available. Generally, a removal of wires and multiple labora- Full Arch Boil & Form, Archtek, Inc) curled-in edges quickly spread back microwave oven, a coffee cup, and a pair tory procedures. Those trays can be has the advantage of less shrinkage, open to avoid hanging on the brackets. of scissors are all that is needed to fab- fabricated over the orthodontic braces which means it will cover more brackets Any excess hot water is shaken from ricate the tray. Occasionally, thermo- directly in the mouth without remov- and teeth (Figure 2). One difference in the tray and the tray is inserted from plastic trays may not be long enough to ing wires or bands. Also, even though the insertion technique from a normal the facial direction. The patient’s lips

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must be relaxed to allow insertion of the Bleaching Material for as efficacious. Currently availableT O C salivary lactobacillus in vivo. The hydro- softened tray. Once in the mouth, fin- Caries Control products (Glyoxide, GlaxoSmithKline gen peroxide products used in bleach- ger adaptation is used to form the tray In conjunction with a custom-fitted Consumer Healthcare, www.gsk.com, ing are not as effective for caries con- over the brackets on the facial and the tray made directly in the mouth over and CVS Antiseptic Oral Cleanser, CVS trol since they do not contain urea. lingual (Figure 4). When this is com- the orthodontic bracket is the use of Corp, www.cvs.com) are much more af- pleted, the patient closes onto their an appropriate-viscosity carbamide fordable but lack extensive amounts of Effect on Saliva, Plaque, posterior teeth and applies suction to peroxide material. Bleaching materi- carbopol thickening agent, thus are not Caries, and Gingival Health form the tray with their lips (Figure 5). als are ideal to use in the tray because maintained in the tray as long as dentist- Ammonia resulting from carbamide The tongue can also be used to push their high viscosity maximizes contact provided bleaching agents. OTC prod- (urea) degradation plays a significant the tray against the lingual of the arch. time and minimizes leakage from the ucts can be worn in the tray for a mini- role in modifying salivary and plaque When the tray has completely cooled tray. Tray application is ideal overnight mum of 1 hour, and still provide some pH. In the 1960s, it was demonstrated in the mouth, the edges are disengaged since the carbamide peroxide bleaching additional cleaning. Whichever material that application of urea solutions to from the brackets (Figure 6). The tray materials are effective for overnight ap- is selected, only the amount that will cov- plaque resulted in an initial rapid rise can then be removed, and the result is plication. If this is not reasonable, then er the tooth surface without excessive in pH followed by a slow fall. The rise a custom-fitted tray made directly in the carbamide peroxide can be used for leakage from the tray should be utilized in plaque pH was related to urea con- the mouth over the braces (Figure 7). daytime use at a minimum of 2 hours. to conserve materials. It is wise to have centration.15 More recently, 10% CP ap- A pair of scissors can be used to remove The one disadvantage of bleaching ma- the patient demonstrate use prior to plied by wearing a custom tray resulted any excess, as well as to remove the tray terials is the relative cost for long-term dismissal from the office to ensure they in a significantly increased salivary pH handle (Figure 8). The tray is reinserted use. Typical orthodontic wear uses about understand the location and amount of after 5 minutes of wear even though the to ensure that the occlusion is comfort- one syringe for 3 to 4 nights when using material to use (Figure 10). CP products tested had an acidic pH able, and the tray handles have been re- a 10% carbamide peroxide product, and (4.8 to 5.2). Salivary pH remained el- moved smoothly (Figure 9). If needed, the refill kits of four syringes cost about Carbamide Peroxide (CP) and evated above 8 for the 2 hours of tray an acrylic trimming bur can be used to $4 per syringe, so the additional cost its Antibacterial Properties wear for the test period.16 The buffering smooth where the handle was adapted. for treatment over a 2-year treatment There are two basic formulations of effect of CP in custom trays extends to The mandibular tray can be fabricated regime would be about $500. However, peroxide materials used in tray bleach- plaque pH; measurements of plaque in the same manner, although it is more compared to the cost of restorative treat- ing. The initial tray ingredient in the pH during 2 hours of CP application difficult to fit. Only one tray is worn at ment and the cycle of replacement resto- original 1989 article was carbamide by custom tray showed that mean fi- a time, since the trays are constructed rations that could be avoided, this may be peroxide, which is active for 2 to 10 nal plaque pH was significantly higher with the patient occluding into MI and minimal. Other options to be considered hours. Hydrogen peroxide has also (8) than baseline (7).17 These results are somewhat bulky. The best regime is are existing OTC products, but none been introduced, but is only active for confirm the buffering effect of urea on to alternate nights of wear. has the appropriate consistency to be up to 1 hour, so it is primarily for day- saliva, since the normal urea concen- time use in bleaching. Ten percent CP tration in saliva has a significant role is the commonly used percentage in in elevating plaque pH and in negat- tooth-bleaching procedures and is the ing the rise in plaque pH after sugar most thoroughly researched CP formu- challenge.18 The critical pH at which lation. It decomposes into 6.5% urea and enamel and dentin begin to dissolve is 3.5% peroxide. The urea further breaks 5.2 to 5.7 for enamel, and 6 to 6.5 for down to ammonia and carbon dioxide. dentin.19 These studies demonstrate Peroxide breaks down to water and oxy- elevation of plaque and salivary pH gen. Carbopol (carboxy polymethylene significantly above these levels; this polymer) is added to many commercial presumably results in a lower rate of bleaching preparations because it in- caries.20 Elevation of saliva pH by CP creases the viscosity of the gel, increases also allays fears that acidic bleaching contact time, and slows the release of agents may cause enamel erosion. It is fig. 11 oxygen from CP.11 Adding carbopol to important to note that bleaching agents CP preparations extends the maximal that contain hydrogen peroxide, but oxygen release time up to 10 hours, de- not CP, do not have these pH elevating pending on how it is measured.12,13 The effects, since it is the urea released from antibacterial properties of CP are well CP that causes elevation of plaque and documented, as the original material was salivary pH. Thus hydrogen peroxide- marketed as an oral antiseptic. In addi- based agents would not necessarily tion, artificially demineralized fissures have the same cariostatic benefits. (to simulate caries) inoculated with lac- A similar study confirmed that sali- tobacillus, and then treated with 10% CP vary urea levels strongly correlated gel for 2 hours showed no subsequent with plaque pH, very possibly causing a growth of lactobacillus when plated.14 lower caries rate than controls or trans- fig. 12 The authors of this study concluded planted patients.21 This confirms the as- that 10% CP penetrated the carious fis- sumption that elevation of salivary and CLINICAL RESULTS (11.) This patient has used 10% CP for over 2 years in these trays. The trays were remade every 2 to 4 months, depending sures and killed the lactobacillus. It has plaque pH by a constant source of sali- on the movement of the teeth. (12.) After removal of the brackets, there also been shown that 10% CP inhibited vary urea (for example from CP bleach- are no yellow spots or unbleached areas on the teeth, and no white spots growth of Streptococcus mutans and lac- ing agents) may inhibit caries. Such car- from demineralization of the enamel. tobacillus in vitro and reduced levels of ies inhibition has been demonstrated in

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The second concern expressed of therapy, there may be times when one bleaching during orthodontic treat- tooth hits high, and becomes sore. The ment is that there will be a “yellow spot” tray levels the occlusion so all teeth are remaining after the bleaching. However, in contact and provides a relief to oc- this has not been shown to be true either, clusal trauma even when no bleaching as the peroxide passes easily through material is added. the tooth in 5 to 15 minutes,28 and will Additionally, because the tray covers bleach under any composite or veneers29 the brackets and wires of the anterior already in the mouth (Figure 11 and portion of the mouth, it provides pro- Figure 12). If there were to be any yellow tection from the irritations to the lips spots, those are most likely the residual and cheeks of orthodontic hardware, composite from the bonding procedure, much in the same manner as wax, but which will be embedded into the tooth much smoother. The oral antiseptic at least 25 µm (Figure 13). Abrasion properties of the bleaching material techniques must always be used after also help with ulcer healing, because fig. 13 debonding orthodontic brackets to this was the original use of carbamide remove this composite. Even if there peroxide. The bleaching material also were a chance of a yellow spot, the sim- helps in controlling malodor, since it ple solution would be to re-bleach the provides a bubbling action to clean the teeth. However, it has been shown that teeth of food debris, as well as provide a a tooth cannot be "spot bleached" due to bacteriostatic cleaning of interproximal the easy passage of peroxide from facial spaces from its oral antiseptic activity. to lingual, and all clinical examples of As has been noted earlier, the disad- bleaching during orthodontics have not vantage of the tray options is that they shown any hint of an unbleached spot. only come in one size. Hence, the tray Concern has been expressed about fabricated in this manner may not cov- the long-term use of the material, and er all the teeth (Figure 14). Because the the swallowing of material. However, tray was made with the patient occlud- fig. 14 the safety of 10% carbamide peroxide ing into MI, this does not create an oc- has been demonstrated pre-bleaching clusal problem. The question concerns CLINICAL RESULTS (13.) Any yellow or discolored areas on the teeth in use in newborn infants, and in pre- whether the teeth not covered will be will generally be attributed to the composite bonding material, which vious long-term uses.30-32 The original protected. However, because the eleva- penetrates 25 µm into the enamel, and must be removed by abrasion. product (Proxigel) was approved as tion of the pH is the primary mechanism (14.) Because the thermoplastic trays only come in one size, the most posterior teeth are often not included in the tray. However, the increase in Generally Recognized as Safe (GRAS) for reducing caries activity rather than pH in the mouth may still protect them from caries. for use as an oral antiseptic by the US plaque removal, it may not be as criti- Food and Drug Administration for the cal to cover all teeth, but rather have a the rat model, where topical application than the hope to avoid tooth decay. life of the patient.33 tray that will hold the 10% carbamide of 10% CP significantly reduced plaque Additionally, the long-term treat- peroxide in place during the night to accumulation and numbers of smooth Expressed Concerns ment of tetracycline patients has shown elevate the pH above that which tooth surface enamel lesions.22 Concern is often expressed of the impact no detrimental effects on the teeth,34,35 decay can occur. When cross elastics the bleaching material will have on the and the 20-year history of research on are worn during orthodontic treatment, Side Effect of Bleaching for orthodontic bond strength. However, the technique36,37 has shown the low- this technique cannot be used. Other Caries Control research has shown that the oxida- concentration, neutral-pH bleaching options used during orthodontic ther- The technique for using bleaching ma- tion process of bleaching will actually products from reputable manufactur- apy when elastics are being worn is to terials for caries control has been pre- strengthen the polymerization of the ers to be as safe to the teeth as normally squirt the 10% carbamide peroxide viously reported in elderly patients.23 composite-bonded brackets by fur- ingested food stuffs and drinks. The material directly into spaces that are The rise in pH creates an environ- ther curing the composite.25 Generally, more recent review of all the litera- hard to clean for the mechanical deb- ment in which caries cannot flourish. composite only cures about 70%, so the ture on safety by the European market ridement of those areas. However, because it creates a basic pH, addition of carbamide peroxide fur- further strengthens the safety of 10% At this time, it is unknown whether then calculus is more likely to form.24 ther increases the bond strength of the carbamide peroxide.38 this technique needs to be applied con- It has been noted in the orthodontic brackets. The opposite of this is true if tinually, or if it can be done for a week to patients that more calculus is present, bleaching is performed before bonding. Additional Benefits clean, then do every other or third day. often getting in the channels for the In that case, the residual oxygen in the of the Tray More research is needed in this area as wires. However, it was determined tooth reduces the bond strengths by In addition to having a custom-fitted to the elevation of the pH and how long that cleaning calculus was more rea- 25%.26 Patients should wait at least 2 tray that provides a carrier for the it takes to drop below the critical levels sonable than dealing with caries. weeks after bleaching before any bond- bleaching material to remove the to allow caries to progress, as well as The other possible side effect is that ing procedure is attempted, to allow the plaque and elevate the pH, the tray also the amount of plaque removed and how the teeth may get whiter. However, for complete dissipation of the oxygen from provides additional benefits. Because it long takes it take to rebuild. This may most patients in orthodontic treatment, the enamel.27 However, once the bond- was made with the patient occluding vary from patient to patient. Disclosing this is desirable. For teenagers, this may ing has been polymerized, then bleach- into maximum intercuspation, the pa- tablets may show effectiveness over time. be the motivating reason to wear the ing over the bonding will further poly­ tient has a stable MI bite registration in Additional cleaning appointments for tray with the bleaching material, rather merize the composite. which to rest. Often during orthodontic the increased amount of calculus may

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need to be included in orthodontic plans. 5. Zinner DD, Duany LF, Chilton NW. Res. 1986;65(7):955-958. 37. Ritter AV, Leonard RH Jr, St Georges AJ, As with any bleaching technique, sen- Controlled study of the clinical effectiveness 21. Peterson S, Woodhead J, Crall J. Caries re- et al. Safety and stability of nightguard vital sitivity may be a side effect.39 However, of a new oxygen gel on plaque, oral debris and sistance in children with chronic renal failure: bleaching: 9 to 12 years post-treatment. J Esthet to date, the sensitivity associated with gingival inflammation. Pharmacol Ther Dent. plaque pH, salivary pH, and salivary composi- Restor Dent. 2002;14(5):275-285. orthodontic therapy exceeds any noted 1970;1:7-15. tion. Pediatr Res. 1985;19:796-799. 38. European Commission: Scientific during this process. Additionally, the 6. Shipman B, Cohen E, Kaslick RS. The effect 22. Firestone AR, Schmid R, Muhlemann HR. Committee on Consumer Products: March use of potassium nitrate in the bleach- of a urea peroxide gel on plaque deposits and Effect of topical application of urea peroxide 2005 SCCP/0844/04. ing materials, or the topical application gingival status. J Periodontol. 1971;42:283-285. on caries incidence and plaque accumulation 39. Swift EJ. Critical appraisal: at-home bleach- of potassium nitrate, should help any 7. Napimoga MH, de Oliveira R, Reis AF, et in rats. Caries Res. 1982;16:112-117. ing: pulpal effects and tooth sensitivity issues, Part problems.40,41 The use of orthodontic al. In vitro antimicrobial activity of peroxide- 23. Haywood VB. Bleaching and caries con- 1. J Esthet Restor Dent. 2006;18(4):225-228. trays for both bleaching application based bleaching agents. Quintessence Int. trol in elderly patients. Aesthetic Dent Today. 40. Haywood VB, Caughman WF, Frazier KB, et and sensitivity application is another 2007;38:329-333. 2007;1:42-43. al. Tray delivery of potassium nitrate-fluoride adjunct to orthodontic therapy. 8. Gurgan S, Bolay S, Alacam R. Antibacterial 24. Dawes C. Why does supragingival calculus to reduce bleaching sensitivity. Quintessence activity of 10% carbamide peroxide bleaching form preferentially on the lingual surface of Int. 2001;32:105-109. Conclusion agents. J Endod. 1996;22:356-357. the 6 lower anterior teeth? J Can Dent Assoc. 41. Pashley DH, Tay FR, Haywood VB, et al. A technique has been presented to fabri- 9. Haywood VB, Caughman WF, Frazier KB, 2006;72:923-926. Consensus-based recommendations for the diag- cate a thermoplastic tray directly in the Myers ML. Fabrication of immediate thermo- 25. Tanner JC, Smith BL, Rueggerberg FA, nosis and managements of dentin hypersensitiv- mouth over orthodontic brackets with- plastic whitening trays. Contemporary Esthetics Haywood VB. Effect of dentist-prescribed ity. Inside Dentistry. 2008;4(9):Special Issue. out removal of the brackets and without and Restorative Practice. 2001;5:84-86. home bleaching on orthodontic bracket reten- traditional impression techniques. The 10. Oliver TL, Haywood VB. Efficacy of night- tion. J Dent Res. 2001;80(#1359):205. fabrication of this tray allows the patient guard vital bleaching technique beyond the 26. Lai SCN, Tay FR, Cheung GSP, Mak YF, to use 10% carbamide peroxide nightly borders of a shortened tray. J Esthet Dent. Carvalho RM, Wei SHY, Toledano M, Osorio R, as a means to reduce plaque and elevate 1999;11:95-102. Pashley DH. Reversal of compromised bonding in the pH in the mouth above that which 11.Haywood VB. Nightguard vital bleaching: a bleached enamel. J Dent Res 2002;81(7):477-481. will cause tooth decay. The goal of this history and products update: part 1. Esthetic 27. Haywood VB. The “bottom line” on bleach- technique is to reduce or eliminate the Dentistry Update. 1991;2(4):63-66. ing 2008. Inside Dentistry. 2008;4(2):82-89. need for restorations to restore white- 12. Matis BA, Gaiao U, Blackman D, et al. In vivo 28. Cooper JS, Bokmeyer TJ, Bowles WH. spot and caries lesions after orthodontic degradation of bleaching gel used in whitening Penetration of the pulp chamber by carb- treatment. No negative sequelae have teeth. J Am Dent Assoc. 1999;130:227-235. amide peroxide bleaching agents. J Endod. been noted when this technique is used 13. Matis BA. Degradation of gel in tray 1992;18:315-317. clinically, other than the additional cost whitening. Compend Contin Educ Dent. 29. Haywood VB, Parker MH. Nightguard vital of the trays and material. 2000;21(28):S28-S35. bleaching beneath existing porcelain veneers: a 14. Amaechi BT, Barghi N, Jouett RM, Summit case report. Quintessence Int. 1999;30(11):743- Acknowledgments J. Bacteriocidal effects of carbamide peroxide 747. Thanks to Dr. Michael Rogers, ortho- bleaching gel [abstract 3245]. IADR/AADR/ 30. Munro IC, Williams GM, Heymann HO, dontist in Augusta, Georgia, and Dr. CADR 83rd General Session (March 9-12, Kroes R. Use of hydrogen peroxide-based tooth Eladio DeLeon, Goldstein Chair of 2005) Available at: http://iadr.confex.com/ whitening products and its relationship to oral Orthodon­tics for Medical College of iadr/2005Balt/techprogram/abstract_58536. cancer. J Esthet Restor Dent. 2006;18(3):119- Georgia, for their help in developing htm. Accessed December 1, 2009. 125. this technique. 15. Kleinberg I. Effect of urea concentration on 31. Li Y. The safety of peroxide-containing at- human plaque pH levels in situ. Arch Oral Biol. home tooth whiteners. Compend Contin Educ Disclosure 1967;12:1475-1484. Dent. 2003;24(4A):384-389. Dr. Haywood has been a consultant to and/or 16. Leonard RH Jr, Bentley CD, Haywood 32. Haywood VB. History, safety, and effec- received grant support from GlaxoSmithKline VB. Salivary pH changes during 10% carb- tiveness of current bleaching techniques and and Archtek, Inc. amide peroxide bleaching. Quintessence Int. applications of the nightguard vital bleaching 1994;25:547-550. technique. Quintessence Int. 1992;23:471-488. References 17. Leonard RH, Austin SM, Haywood VB, 33. Haywood VB. The Food and Drug 1. Haywood VB. Tooth Whitening: Indications Bentley CD. Change in pH of plaque and 10% Administration and its influence on home and Outcomes of Nightguard Vital Bleaching. carbamide peroxide solution during nightguard bleaching. Current Opinion in Cosmetic 2007; Quintessence Publishing Company Inc: vital bleaching treatment. Quintessence Int. Dentistry. 1993:12-18. Hanover Park, Ill. 1994;25(12):819-823. 34. Matis BA, Wang Y, Eckert GJ, Cochran MA 2. Bentley CD, Leonard R, Crawford JJ. Effect 18. Didbin GH, Dawes C. A mathematical Jiang T. Extended bleaching of tetracycline- of whitening agents containing carbamide model of the influence of salivary urea on the stained teeth: a 5-year study. Oper Dent. peroxide on cariogenic bacteria. J Esthet Dent. pH of fasted dental plaque and on the changes 2006;31(6):643-651. 2000;12(1):33-37. occurring during a cariogenic challenge. Caries 35. Leonard RH Jr, Haywood VB, Caplan CJ, et 3. Shapiro WB, Kaslick RS, Chasens Al, Res. 1998;32:70-74. al. Nightguard vital bleaching of tetracycline- Eisenberg R. The influence of urea peroxide 19. Eliasson S, Krasse B, Soremark R. Root car- stained teeth: 90 months post treatment. J gel on plaque, calculus and chronic gingival ies. A consensus conference statement. Swed Esthet Restor Dent. 2003;15(3):142-152. inflammation.J Periodontol. 1973;44:636-639. Dent J. 1992;16:21-25. 36. Haywood VB. Considerations for vital night- 4. Reddy J, Salkin LM. The effect of a urea 20. Hoppenbrouwers PM, Driessens FM, guard tooth bleaching with 10% carbamide peroxide rinse on dental plaque and gingivitis. Borggreven JM. The vulnerability of unexposed peroxide after nearly 20 years of proven use. J Periodontol. 1976;47:607-610. human dental roots to demineralization. J Dent Inside Dentistry. 2006;2(7):2-5.

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