Apexification: review of the literature Donald R. Morse* / James O'Larnic** / Cctnil Yesilsoy**"
Five methods for the treatment of teeth with an incompletely formed ape.\ (open apex) and a necrotic pidp are discussed. The methods discussed include the u.Ke of{\) a cus- tomized cone (blunt-end, rolled eone); (2) a short-fill technique; (3) periapical surgerv (with or without a retrograde seal): (4) apexification (apical closure induction); and (5) one-visit apexification. The apexification techniques, which use various formulations of calcium hydroxide to induee closure, are stressed. Ba.sed on the review of the litera- ture and clinical experience of the authors, it was concluded that sucee.ssful treatment of an immature ptdpless tooth can partly result from the antibacterial atid calcifieation- indueing action of calcium hydroxide. (Quintessence Int 1990.21:589-598.)
Introduction Currently, there are at least five methods of treating a tooth that has a necrotic pulp and an open apex. Apexification is a method of inducing apical closure These methods are (1) filling the root canal with the through the formation of mineralized tissue in the ap- large (blunt) end of a gutta-pereha cone or customized ical pulp region of a nonvital tooth with an incom- gutta-percha cones with a sealer; (2) filling the root pletely formed root (open apex). The mineralized tis- canal well short of the apex (before the walls have sue can be composed of osteocementum. osteodentin, diverged) with gutta-percha and sealer or zinc oxide- or bone or some combination of the three.' Apical eugenol (ZOE) alone; (3) filling the root canal with closure can take various forms. It can be a compiete gutta-percha and sealer as well as possible and then or an incomplete hard tissue bridge a few millimeters performing periapical surgery with or without a re- short of the end of the root. It can be located at the verse seal; (4) inducing apical closure by the forma- tip of the root, or the bridging can be an irregular tion ufan apical stop (calcium hydroxide [Ca(OH))] mass of calcification traversing the apical one third of is generally used) against which a permanent root can- the root. In most cases, apicai closure takes an irreg- al filhng can subsequently be inserted; and (5) placing ular and aberrant form.' Along with apical closure, a biologically acceptable substance in the apical por- root development or lengthening may or may not con- tion of the root canal (dentinal chips or tricalcium tinue, but whatever the form, root development is usu- phosphate have been used) thus forming an apical ally irregular and aberrant. In contrast, apexogenesis barrier; this is followed by filling the root canal with treatment (vital root-end closure) results in regular gutta-percha and sealer. The last procedure has been apical closure and normal-appearing root develop- called one-visit apexification.'"' Each of these tech- ment.^ niques will be examined.
Blunt-end or rolled cone (cnstomized cone) Filling the root canal with the large end of a gutta- Professor and Research Director. Department of Endodontol- ogy. Temple University, School of Dentistry, 3223 North percha cone or a customized cone is not advisable Broad Street, Philadelphia, Pennsylvania 19140. because the apical foramen i.'; generally wider than the Formerly, Second-Year Graduate Student, Department of En- root canal orifice.^'' This would prevent proper con- dodotitology. Temple University. Presently, Private Practice, Philadelphia, Pennsylvania. densation of the gutta-percha, and proper preparation Associate Professor and Director of Undergraduate Clinic, of the canal would weaken the tooth considerably.'" It Department of End odon to logy. Temple University. would also he difficult to assess the point of root de-
Quint^sence International Volume "S^ Number 7/1990 589 Endodontics vdopmcnt radiographically because root formation in treatment of teeth with a necrotic pulp, the basic aim the buecolingual plane is less advanced than it is in should be stimulation and preservation ol the torm- the mesiodistal plane." ative activity of the granulation tissue cells in the ap- ical part of the root canal. This should enhance the formation of a calcified callus in the wide apical open- Short-fill ing,-- Moodnick'" proposed removal of the bulk of the ne- The use of Ca(OH), to induce apical closure was crotic tissue and tilling the root canal short of the first introduced in 1964 by Kaiser,-' when he proposed apex with gutta-percha. He advocated use of Diaket*'" that use of CaiOH): mixed with camphorated para- (Premier Dental Products), a compound of beta-ke- chlorophenol (CMCP) would induce the formation of tones and zinc oxide, in place of gutta-percha to en- a calcified barrier across the apex. His procedure was hance healing. However, with an incomplete obtura- popularized in 1966 by Frank,'* who described a step- tion, microbes can be left remaining within the apical by-step technique and four types of apical closure. For part of the root canal system, and healing may not the procedure to be effective, it has been hypothesized take place or periapical breakdown may occur later." tbat Ca(0H)2 paste must contact vital tissue, although this has never definitely been proven."'' It has also been shown that the larger the apical opening, the longer Periapical surgery the time necessary to induce apical closure. However, The gutta-percha/sealer surgical approach has many no consensus exists on how frequently the dressings drawbacks. Many clinicians''"'''"''* do not advocate this have to be changed to induce apexification,'''"-'•''-'' method of treatment for one or more of the following Heitbersay"-' and others-**-' have induced apieal reasons: closure using Ca(0H)2 and methylcellulose {Pulpdent, Pulpdent Corp), Pulpdent has the advantages of de- 1, Relative to the already shortened roots, further re- creased solubility in tissue fluids and firm physical duction could result in an inadequate crown-to-root consistency,-' ratio. A different approach with Pulpdent has been used 2, Surgery could be both physically and psychologi- by Senzamici and Tesini,^" In their technique, a master cally traumatic to the young palient, cone is fitted 3 mm from the apex, and, prior to ob- 3, The young patient is not apt to be cooperative, turation, the apical 3 mm is filled with Pulpdent, 4, Surgery would remove the root sheath and prevent the possibihty of further root development, Nygaard-Ostby^' suggested laceration of the periap- ical tissues with a file until bleeding oceurs, to result 5, The apical walls are thin and could shatter when in the further development of the root apex, touched by a rotating bur, Zussman" showed that the vascularity of the apical 6, The thin walls would make condensation of a re- region facilitates and favors further root development trograde material difficult. This can result in an by the root sheath once the tissues are in a healthy inadequate seal, state. However, Ham and coworkers" have not re- 7, The periapical tissue may not adapt to the wide ported much success with the induced blood clot,^" and irregular surface of the amalgam. and Citrome and coworkers''' have reported that the However, for cases in which a more conservative blood clot maintained the initial infiammatory state approach is not feasible, Dawood and Pitt Ford-' have and did not result in hard tissue bridging at the apex. given evidence that tbe obturation of the root canal Rule and Winter'" utilized instrumentation to in- with thermoplasticized gutta-percha/sealer followed duce bleeding and believed that this tissue may have by periapical curettage can be clinically sticcessful. not undergone necrosis and could therefore aid in fur- ther apical closure and root development. Torneck and Smith"" reported that any attempt to retain a residual Apical closure induction pulp stump in the apical one third of the root canal Induction of apical closure or an apical stop has be- results in the formation of a periapical abscess. They come the most widely used approach to treating these also reported that, despite the absence of remedial teeth. Many materials and metbod.s have been used therapy, continued root growth can occur. The calcific successfully, but the exact mechanism of action re- bridge at the apex in some eases appears lo be related mains a mystery. It has been considered that in the more to the ingrowth of trabecular bone.
590 Ouintessencâjfii 7/1990 Endodontics
Leibeiman and Trowbridge" and Barker and glycerine has been added to improve the consistency, Mayne'' haye reported cases of root-end closure with- and barium sulfate has been added to make the paste out pulp therapy or endodontic therapy, Israel"" was more radiopaque."* However, Smith and Woods'* sug- able to obtain continued apical development after use gested that the use of diatrizoate compounds (soluble of biomechanieal cleaning alone. Das'' considered organic iodine) be used as a substitute for barium that minima! mechanical intervention and removal of sulfate. The diatrizoate compounds are resorbable and infection alone would be suffieient to induce apical will not obscure the apex if the paste is extruded peri- closure. Conversely, other studies'"^""- have reported apicaily. that cases in which the root canals were thoroughly Other pastes have been used to induce apical clo- cleaned and shaped had a decreased incidence of root sure, including pastes that contain antibiotics,^^-^''^^ formation compared to eases in which the root canals Cooke and Rowbotham'"* used an antiseptic paste con- were instrumented less thoroughly, England and Besf" taining zinc oxide, cresol, clove oil, iodoform, and thy- stated that the thorough cleaning of the root canal mol. Other investigators*'-^' consider this apical paste may be the primary factor responsible for apical clo- to be a protoplasmic poison that would further irritate sure. They believed, as did Chawla and coworkers,*" the periapical tissues. that a catalyst paste is unnecessary to induce apical When Vojinovic and Srnic'" eompared the use of closure. Some investigators'*^'"^ concluded that, al- Ca(OH)i to the use of iodoform Chumsky paste (30 though apexification is a natural phenomenon, it must g phenol, 30 g camphor, 110 g absolute alcohol), they be stimulated by a biologic activator, found more calcified tissue and a more complete clo- Klein and Levy''' and others""^"" have successfully sure with Ca(OH);, They beUeved that, although some induced apical closure using Ca(OH)2 and Cresatin stimulation of the eells of the granulation tissue is (Premier Dental Products), a metacresylacetate, necessary, the paste was more irritating than is nec- Weiss,'" using tiiis mixture as a pulp capping agent, essary. reported more rapid healing with it than with the use Other materials that have been used with some suc- of Ca(OH); and water, cess are Calosept (Scania Dental)," an iodoform-eon- Cresatin has been shown to have minimal infiam- taining paste," Hypocal (Ellman Co)," a chloromy- matory potential as a root canal medicament" and cetin-containing paste,"* and ZOE pastes," minimal cytotoxicity when compared with CMCP,^^ Bernard" showed that apical development occurred Camphorated parachlorophenol has also been shown after sterilization of the periapical tissues followed by to be a highly toxic preparation capable of causing filling of the root canals with a calcium oxide-con- tissue necrosis. However, Dylewski^' saw no evidence taining paste, Matsumiya and Kitamura'* compared of irritation after use of CMCP in the periapical tis- the effect of antibacterial treatment using antiseptic sues of monkeys. and antibiotics with the effect of physiologic saline If CMCP or Cresatin is mixed with Ca(OH):, a before the canals were filled with Ca(0H)3. The com- chemical reaction occurs and results in the formation parison was a histopathologic and histobacteriologic of the calcium-p-chlorophenolate and calcium cresy- examination of the root canals from the teeth of in- late salts, and, after 2 weeks, Ca(OH); and Cresatin fected dogs. There was no statistically significant dif- have been observed to form acetic aeid,^"" These com- ference between the two groups. This can be related pounds are difficult to remove from root canals.'" It to the long-term antibacterial effect of the Ca(0H)2, has also been shown that the combined pH of Cresatin which has heen demonstrated, in vitro, to be bacte- and Ca(0H)2 decreases faster than the pH of the com- ricidal and antiseptic. According to some authorities, bined CMCP and Ca(OH):. the chance of a successful outcome are lessened if a negative microbiologie culture cannot be obtained," Calcium hydroxide, when mixed with a number of The formation of calcified tissue is considered to oecur different substances, has been succe.ssful in inducing in the absence of microorganisms.'"* It has been apical closure,'^•^'^ Since its introduction, Ca(OH), has shown that Ca(0H)2 accelerates hard fissue bridging been mixed with CMCP.' distilled water," sterile at the apex irrespective of the initially induced infiam- water,'^•^'•" sterile saline,^"-*' anesthetic solutions (pref- matory state,^"' erably without vasoconstrictors),''- chlorothymonal,*^ Cresatm, Cresanol (Premier Dental Products), a mix- A study by England and Besf*^ found that apical ture of CMCP and Cresatin, Ringer's solution, meth- closure occurred more frequently in teeth left open to ylcellulose, and todoform,'"" In some formulations. the oral environment (86,5%) than in those closed to
rnationa) Number 7/1990 591 Endodonties it (50%). This was in agreement with Torneck et al,"" would, in turn, serve as a nidus for further calcifica- who hypothesized that exúdate in the closed root eanal tion. Javelet and coworkers**^ also indicated that the has no pathway for drainage. This fiuid can accu- alkalinity is a significant feature in the abihty of mulate in the root canal, thus impeding repair. Ca(0H)2 to induce hard tissue formation. Other Ludlow'^ reported on a case in which a tooth with a investigators""-"' contended that Ca(OH): creates an large periapieal lesion did not respond to Ca(OH); unfavorable environment for osteoclastic activity or and CMCP treatment until the lesion was curetted. can activate alkaline pbosphatase enzymes. The latter The mechanism of apieal closure is still in question. have been suggested as playing a role in hard tissue Some investigators''•'*'*'°-^' believe that the root sheath formation. Yesilsoy and coworkers"" have shown that remains intact and resumes its function once the Ca(OI-I);, hy itself and as a component of root canal source of infection is eliminated. Klein and Levy^' sealers, can induce calcification even in a soft tissue believed that the ceils of the dental sac around the environment. apex retain their genetic code that predisposes them When preparing the Ca(OH): paste using anesthetic to form into cementoblasts. Torneck and Smith'* solutions, Stamos and coworkers*' determined that maintained that remnants of the dental pulp remain such a small amount of liquid is used that no appre- vital and function in spite of inflammation. Therefore, ciable change occurs in the pH. Mitchell atid confinued root development can be a feature of the Shank walker'*" concluded that it is difficult to ascrihe chronic phase of pulpal disease and is not necessarily any importance to the pH of the material when the a product of treatment. osteogenic potential is considered. They rationalized In other studies in which apical elosure was induced, that the use of other materials that have relatively high it was not possible to identify the root sheath in any pH values do not result in consistent hard tisstie for- section of teeth with either partial or complete root mation. This is also supported hy the investigations closure. West and Lieb*" reported a ease in which the of Binnie and Mitchell.'" periapex of an incisor was curetted following conven- McCormick and eoworkers'- maintained that the tional endodontic therapy. After II years, the tooth rehance on medication alone'" to aeeompli.sh a pH rise was then sueeessfully treated by the use of Frank's in the periapex, as proposed by Van Hassell and Nat- technique. kin," is unrealistic. They beheved that other proce- Some investigators have proposed that Ca(0H)2 dures are of considerable importance in gaining con- stimulates undifferentiated mesenchymal cells to dif- tinued apical development. These procedures include ferentiate into cementoblasts, which, in turn, initiate ( 1) adequate preparation of the root eanal; (2) re- cementogenesis at the apex."*"*- Dylewski'^ observed moval of necrotic tissue and substrate; (3) reduction proliferating connective tissue in the apical region that of microbes (both in terms of numbers and virulence); differentiated into calcific material, whieh became and (4) a decrease in the root canal space. Frank'*''' continuous with the predentin at the apex. Sehroder concluded that the reduction of contaminates in the and Granath" maintained that this calcification pro- root canal and the filling of the root eanal space with cess occurs beneath a superficial layer of necrosis. a temporary resorbable material are more important They considered that the necrosis was related to the than which material is tised. high pH of the Ca(OH):. Nyborg^' and other investigators"''*-^' thought that Heithersay" considered that the alkalinity of the pulpal reaetion to Ca(0H)2 depended on the hydroxyl material can act as a buffer to acidic inflammatory ion rather than the calcium ion. Nevertheless, in one reactions. As a result, the Ca(0H)2 has a favorable study,''"' in which magnesium hydroxide (Mg[0H]2) was effect on bone healing. Tronstad and coworkers*" have used in 14 apexification procedures, the results showed shown thai the pH of untreated teeth with pulpal ne- four mild and ten severe inflammatory reactions. Con- crosis is between 6.0 aud 7.4. Teeth with complete root tradictory results were found when Mg(0H)2 was im- formation have a pH between 7.4 and 9.6 in the dentin planted subdermally in rats." Magnesium hydroxide away from the pulp and from S.O to 11.1 in the dentin was found to have less of an inflammatory reaction next to the pulp. These investigators maintained that than has CaiOH),. In one investigation,*" barium hy- the Ca{OH)- neutralizes acids produced by osteo- droxide was substituted for CaiOH);. Observations clasts. Anthony and coworkers-'' concluded, that the from this study included a lack of bridge formation, alkaline environment would favor the formation of a severe foreign body reaction, and acute and chronic calcium phosphate (Ca[PO].i) complexes, whieh inflammation with epithelial proliferation.
592 \ l^\ i imn 7/1990 Endodontics
The calcium ion was also thought to be necessary (1) acts as a matrix for the invasion of blastic cells, to decrease capillary leakage and constrict the pre- (2) allows for cellular proliferation and differentia- capillary sphincters." In addition, the calcium ion can tion, and (3) permits deposition of hard tissue. Stud- also affect the enzyme pyrophosphatiise, which is cal- ies have shown thai resorbahle ceraniie is replaced by eium dependent. Pyrophosphate is involved in eolla- bone. "'^"'5 gen synthesis and. therefore, stimulation of thi.s en- Koenigs and coworkers'"'' simulated conditions of zyme can increase the defense and repair mecha- an open apex in 24 monkey teeth and packed the ap- nisms.-' ical 3 to 4 mm with caleium phosphate ceramic. At Nevins and coworkers^* used a Ca(P0)4 gel to pro- the end of a 24-week period, most of the material had dtice a mineralized scar around the orifices of poly- been resorbed and repliiced by a mineralized tissue ethylene tubes that were placed subcutaneously in rats. that contained nuclei. The tis.sue extended 3 lo 5 mm When plaeed in pulpless open-apex teeth in monkeys, into the root eanal, and it resembled cementum. The the gel resulted in connective tissue ingrowth.**" Nevins periodontal ligament had regenerated with little, if et al^' postulated that this could be a step in revitali- any, inflammation ofthe periapical tissues. However, zation of teeth. In other studies, the Nevins group also the bridge was not complete, and a small channel, reported the sueeessful use of collagen Ca(P0)4 containing connective tissue and blood vessels, was ggl 100,101 Donlon'"- has shown that calfskin collagen observed on one lateral wall. is lmmunologically neutral. In contrast, Citrome and Roberts and Brilliaut"^' compared apical closure in- coworkers''* found that, in dogs, the collagen Ca(P0)4 ducement between triCa(P0)4 (pH = 8.6) and gel inhibited the reparative process of the initial in- Ca(0H)2 (pH = 12.0). Both substances are relatively flammatory lesion, leading to extensive destruetion of successful. They concluded Ihat the use of a highly the periapical tissues. No evidence of apexification alkaline material is unnecessary to induce closure and was found. Heuer'"' reported that collagen Ca{P0)4 felt that particle size might be a factor. TriCa(P0)4 gel failed to assist in the resolution of instrumentation and Ca(0H}2 had nearly identical particle sizes trauma and inhibited tbe repair process. Teeth treated (Ca[OH]> = 2 to 5 \im- triCa[PO]4 = 3 to 5 i^m). with Ca{OH); in the same animals showed an accel- Covicllo and Brilliant""* compared a one-appoint- eration of the repair process. ment technique using either Ca(OH); or triCa(PO).i. Finally, whether or not a eomplete apical barrier Both substances proved successful, but. in contrast to results from apexification techniques is uncertain. Lie- the previously mentioned .study,"" more CaiOH), was berman and Trowbridge-" have shown that even with neeessary to create the apical stop. This result was radiographie and ehnieal evidence of a hard tissue probably due to discrepencies in particle size. barrier, histologie examination shows that this barrier Dimashkieh''^' devised a technique using Surgicel is porous. Nevertheless, for clinical success, it may not (Ethieon Ltd) along with amalgam. Surgicel is an ox- be necessary to have an impermeable hard tissue bar- idized regeneration cellulose that is nonirritating and resorbable. After preparation of the root canal, the Surgice! was inserted through the aeeess opening and packed apically. This was followed by insertion of the One-visit apexification amalgam in the same fashion. Hence, the Surgical was The most recent development in the treatment of teeth used as a base and/or matrix. with a necrotie pulp and an open apex is to condense Rossmeisl and coworkers"*•"' used freeze-dried eor- nonsurgieally a biocompatable material into the apical tieal bone and freeze-dried dentin to create apical end of the root canal. The rationale is to establish an plugs. They found that both materials were bioeom- apical stop that would then enable the root canal to patible with periapical tissues. The freeze-drying pro- be filled immediately This technique has been called cedure appears to inactivate the histocompatibie an- a one-visit apexification. However, it really only fulfills tigens."^"-' one aspect of apexification: the creation of an apical The use of dentinal shavings as a root canal filhng stop. It does not allow for continued root develop- material was first described by Gollmer"* in 1937. ment. Hence, the technique eannut be used for teeth Tronstad"-^ has found dentinal chips to be well toler- with excessively short roots. ated by periapical tissues. Others'"'"' have found that A resorbable ceramic has also been developed. It is the use of dentinal chips increases the formation of a specially prepared form of calcium phosphate that osteocementum in the peri apex.
Internationa , Number 7/1990 593 Endodontics
Table I Summary of techniques for trealment of nonviial teeth that have an open apex
Root-end Histologie Technique closure response Appointments Prognosis Untreated"'' Yes, but only Questionable None Poor case reports Instrumentation alone'''^*''"' Yes, but may be Questionable 1-2 Questionable decreased amount Customized cone^"'" No Unfavorable 2-3 Poor Short mr- Yes, but only Questionable 2-3 case reports Periapical surgery^''"''''"-'' No Unfavorable 1 Fair Apexification Calcium hydroxide'''"-*' Yes Favorable 6-7 Generally good Magnesium hydroxide^'*'*' No Questionable 6-7 Poor Barium hydroxide^" No Unfavorable 6-7 Poor Zinc oxide"-*^''' Questionable Unfavorable 6-7 Poor Calcittm oxide" Yes Questionable 6-7 Fair Calcium phosphate Questionable Questionable 6-7 Questionable collagen gel'*"'"^ Tricalcium phosphate'"' Yes Favorable 6-7 Generally good Other pastes™ " Questionable Questionable 6-7 Questionable One-visit apexification Resorhahle ceramic'"^'"^ No Favorable 1 Fair Tricalcium phosphate'"* No Favorable 1 Fair Calcium hydroxide'"* No Favorable 1 Fair Surgi eel/amalgam'"^ No Questionable 1 Fair Freeze-dried bone or No Favorable 1 Fair or dentin"«-"'
Weisenseel and associates"*' compared apical seals Discnssion of root canals mechanically prepared to simulate open apexes. The root canals were then filled with either Five methods are primarily used to manage teeth with gutta-percha and Tubli-seal (Kerr/Syhron Corp) an open apex and a necrotic pulp: (i) use of the blunt alone, or an initial placement of a 2-mm apical plug end of a gutta-percha cone or rolled gutta-percha of Ca(OH); before the gutta-percha/sealer combina- cones; (2) obturation of the root canal short of the tion. The resuits indicated that the root canals with apex; (3) performance of periapical surgery with or apical plugs (CA[OH]i) demonstrated significantly less without a reverse amalgam seal; (4) use of an apex- leakage than did those without the plugs. ification procedure to create an apical stop: and (5)
594 QuintessenCR Intprnatinpal \/nli 7/1990 Endodontics use of a one-visit apexification procedure by con- cium hydroxide. Which Ca{0H)2 preparation is best densing a biologically acceptable material in the apex is unknown. Suggestions include Ca(OH)2 with dis- followed by obturation of the rest of the root canal tilled water, sterile saline, local anesthetic solution, with gutta-pereha/sealer {Table 1), Cresatin, CMCP, methylcellulose, resins, and other Tbe most frequently used procedure appears to be substances. However, there is no evidence of the su- apexification with Ca(OH);, Its relatively good success periority of any combination over plain Ca(OH)i. In has been attributed to one or more of the following addition, the major factors appear to be the debride- properties: (I) tbe pH; (2) the calcium ion: (3) the ment of the root canal and the reduction of the root hydroxyl ion; and (4) the antibacterial effect. How- canal space with a space-occupying material. The lat- ever, tbe property that actually promotes the mecha- ter two aspects appear to allow the body to reorganize nism for calcific bridge formation is not known. Be- and repair the periapical tissues. fore a wound can heal properly, the bacteria in the To evaluate one-visit apexification further, a sland- area must be removed, inactivated, or greatly reduced ardized method or model must be developed to com- in number. Although Ca(0H)2 possesses antibacterial pare the various materials being advocated. properties, apexification has also been successful with- out the use of this medicament. The common aspects of all apexification procedures are debridement, clean- ing, and reduction of the root canal space with a ma- terial, thus leading to a favorable periapieal environ- References ment,"'*'" Once the infection is eliminated and the peri- 1, Nicholls E: Endodomics, ed 2, BrÍ!.tol, England, John Wright apical tissues reorganize, it is then possible for calcific and Suns Ltd, 1977, pp 254, 258. development to take place.'-" Frank"" has stated tbat 2, Ienica JI, Tsamtosouris A: Continued root end devdopmcm: Ca(OH); paste is often used as a temporary paste fill- apexogenesis and apexification. J Pedod Í978;3:144 156. ing because of its availabihty and its comparative ease 3, Engländer JA: Treatment of non-vital leeth with incompleteiy formed roots. J Dent Med 1956;2:90-96. of removal rather than because of any unique effect. 4, Israel H; Treatment ofan acuteiy infected fiiictiired in;:isor with open apex. Dem Items Interest t950;72:472-476. With the current popularity of single-visit endodon- 5, Hare G: Obliteration of the root canal with open apes. ,t En- tics,'-' tbere has emerged a single-visit apexification as dodontia l948;3:51-35, the result of the formation of an operator-made apical 6, Hartsook JT: Pulpal therapy in primary and young permanent barrier. The successful performance of this one-visit teeth. Dem Clin Noi-lh Am l966;IO:377-389, procedure benefits both patient and practitioner be- 7, ingle J Obliteration of" Ihe llaring apical foramen, Dp'i/Digct/ cause of the reduced amount of office time required. 1956:62:410^12, S. Pollack JR: Endodonlia lor non-vilal teeth with incompletely The problem of patient compliance is also reduced, formed roots. Bult NJ Soc Dem Child iy67;4:2-6, and this can eliminate the problems that can arise with 9. Friend LA: The root treatment of teeth with open apices. Froc extended treatments. In addition, it appears that with Roy Soc Med Odomol 1966:19:1035-1036, multiple visits, the reopening of the root canal, and 10, Friend LA: The treatment of immature teelh with non-vital its recieaning, disturbs the process of apexification."'-'' pulps, J Br Endod Soc 1967;l:28-33. 11. Seltîer S: Endodonlology: Biologic Considerations in Endodontic However, there are reports of conflicting results with Froeedures. ed 2. Philadelphia, Lea & Febiger. 1988, pp 31-54. one-visit apexification procedures-'"^-'"' This technique 12, Moodnick RM: Clinical correlation of the development of the has been performed on dogs, monkeys, and humans root apes and surrounding structtires. Oral Sarg Oral Med Oral and in cases of (I) intact, healthy teeth; (2j experi- Pathol 1963;16:6Oi)-607, 13. Morse DR, Esposilo JV, Pike C, et al: A radiographie evalu- mentally infected teeth; (3) teeth with a naturally wide ation of the periapical status of teeth treated by the gutta- open apex; and (4) teeth with a simulated open apex. percha-eircapercha endodontic method: a one-year follow-up To evaluate one-visit apexification properly, a stand- study of 458 root canals. Oral Sui-g Oral Med Oral Pathol ardized method bas to be devised. 19B3;55:607 610, 56:89-96, 56:190-197, 14. Steiner JC, Dow PR, Cathy GM: Inducing root end closure of non-vital permanent teeth. J Dem Child 1968;35:47-54. 15, Heithersay GS: Stimulation of root formation in incompletely developed pulpless teeth. Oral Surg Oral Med Oral Pathol Conclusions 1970;2962O-630, 16, Frank AL: Therapy for the divergent pirlpless tooth by con- The eventual successful outcome in the treatment of tinued apical formation, J Am Dent Assoc 1966;72:87-93. an immature pulpless tooth can partly result from the 17. Duell RC: Conservative endodontic treatment of the open apex antibacterial and calcification-inducing action of cal- in three dimensions, Dent Clin North Am I973;17:125-134.
595 QuifKössence International Number 7/1990 Endodontics
18, MichaLiowicz J, Michanowicz A: A conservative approach and injury and oral contamination. Oral Surg Orul Med Orul Pu procedure to fill an incompletely Ibrmeil root using calcium /;j
596 Quintesse nee Jutai 7/1990 Endodonties
. Webber RT: Apexogenesis versus upexificiition. Dent Clin pH levels for the induction of apical barriers in inimalure (eelh North Am 19B4;28:659-697. of monkeys. J Endod l985;ll:375-378. . Stewarl GG, Gautier RF: Reduced liinatnmatory root canal K6. ViiesG: Lysosoniesand cellular physiology of bone résorption, medication. Oral Surg Oral Med Oral Piithol 1962;! 5:715-720. in Dingles JI, Fell HE |eds): Lyso.mmes in Biologv imd Pa- . Holland R, De Sotiza LD, Taeliaviiini RL, et al: A histologieal thology, vol 1, AmsEerdam. North Holland Pubi Co, 1969, pp sludy ol" itie effect of calcium hydroxide in the treatment ol" 216-253. piLlpless teelh of dogs. J Br Enilod Soc 1979:12:15-23. 87. Bourne HG: Phosphatase and ealcillCLilion, in Bourne HG . Harrison LM: Continued apical formation m tlie imniauire (ed¡: The Biochemistry and Physiology o/ Bone New York, non-vital tooth. J in Dem Assoc t969;27;6-9. Aeadeniic Press, 1972, pp 79-120. . Sraitti GN, Woods S: Organic iodine: a substitute for barium 8K. Yesilsoy C, Koren LZ, Morse DR, et al: A comparative tissue sulfate in apexificalion procedures. J Endod 15E3;9:153-155. toxicity evaltiation of estabiished and newer root eanai sealers. . Ball J: Apical root formation in a non-vital immature per- Oral Surg Oral Med Oral Pathol 1988:65:459-467. manent ineisor. Br Dent J 1964;116:lñ6-167. 89. Stamos DG, Haasch GC. Gerstein H: The pH of local anes- . Herbert WE: Three cases of disturbance of caleifieation of a [ he tic/calcium hydroxide solutions. / Ejidod 19S5;I1:264-265. tooth and infection of the dental pulp following trauma. Dem 90. Mitchell DF, Shankwalker GB: Osteogenie potential of cal- Pract W59;9:t76-180. cium hydroxide and other materials in soft tissue and bone . Winter GB: The root treatment of infected permanent incisors wounds. J Dent Res 1958:37:1157-1163. in children. Br Dent J 1966;120:ll-n. 91. Binnie WH, Mitchell DF: Induced calcification in the subder- . Vojinovic Ü, Srnié E: Induction of apical formation by the use niLiI tissue of the rat. ./ Dent Re.-r I973;52:1O87-IC91. of calcium hydroxide and iodo form-Chu msky paste in the en- 92. McCormiek JH. Weine FS, Maggio JD: Tissue pH of devel- dodontic treatment of immature teeth. J Br Endod Soc oping periapieal IESJOOS in dogs. / Endod 1983;9:47-51. 1975;8:16-22. 93. Van Hassel H, Natkiii E: Induction of root end closure, y Dc/jf Ghose LJ, Baghdady VS, Hikmat M Apexification of im- CiiiW!970;37:57-59. mature apices of pulpless pennanenE anterior teeth with tal- 94. Frank AL: Endodontic endosseous implants and the treatment cium hydroxide. J Endod i987;13:285-290. of the wide open apex. Dent Clin North Am 1967:11:675-7(10. Bouehon F. Apex formation following treatment of necrotized 95. Nyborg H: A survey of the problems of pulpotomy. Ret- Beig immature permanent incisors. / Dent Child 1956;33:378-38Ü. .Med Dent 1959:14:111-115. . O'Riordan M: Apexiñcation of deciduous ineisor. J Endod 96. Yoshida J: Sttidy on pulp healing following ptilpotomy with 1980;6;607-609. calcium hydroxide. J Osaka Dem Univ 1959;4:525-530. . Rowe AHR, Binnie WH: Histologieal study of the periapical 97. Sciaky I, Pisante S: Localization of calcium placed over am- tissues of incompleiely lormed pulpless teeth filled with zinc pjtated pulps in dogs" teeth. J Dem Res 196O;39;l 128-1132. preparations and with magnesium hydroxide. J Dent Res 98. Nevins AJ. Finkelstein F, Horden BG, et al: Fonnation of 1974;53:605-608. mineralized scar tissue induced by implants containing colla- Bernard P: L'ionophorise la Physiotechnie. Pans, Fotetto, 1957. gen-calcium phosphate gel. J Endod 1975;1:3C3-3O9. Matsumiya M, Kitamura M: Histo-patliological and histo- 99. Nevins AJ, Fiukelstein F, Borden BG, et al: Revi tali îati on of bacteriological studies of the relation between the condition of pulpless open apex teeth in rhesus monkeys using coll agen- sterilization of the lrtterior of the root canal and the heahng calcium phosphate gel. / Endoi! 1976;2:I59-165. process of Ihe periapical tissues in experimentally infected root 10(1. Nevins AJ, Wrobe! W, Vaiachovic R, et al' Hard tisstie induc- canal treatment. Bult Tokyo Dent Coll 1961:1:1-9. tion inlo pulpless open apex teeth using collagen-calcium phos- Crabb HSM: The basis of root-canal therapy. Dent Pract Dent phate gtVJ Endod 1977;3:43H33. Ree 101. Nevins AJ, Finkelstein F, Laporta R, et al: Induction of hard :. Boyle PE: Kronfeld's Histopathohgy of the Teeth and Their tissue into palpless open-apex leeth using col lagen-calcium Surrounding Structures, ed 4. Philadelphia, Lea & Febigei, phosphate gel. / Endod 1978;4:76-B1. 1955, pp 238-240. 102. Donlon WC: Immune neutrality of calf skin collagen gel used . Ludlow MO: Apical closure after nonsurgical apical curettage. to stimulate revitalization in pulpless open apex teeth of rhesus y &ií/oá 1979;5:151-153. monkeys. J Dent Res 1977:56:67o 673. . Smith JW, Leeb IJ. Torney DC: A comparison of calcium 103. Heuer MA' An open question. ADA News 1977:8(8):2. hydroxide and barium hydroxide as agents for inducing apical 104. Driskell TD, Hassler CR. Tennery VJ, MeCoy LR, Clark W: closure. J Endod 1984,10:64-70. Calcium phosphate resorbable ceramics: a potential alternative Feldman G, Solomon C, Notaro PJ' Endodontic management to bone grafting. J Dent Res 1973;52(special issue]:123 {abstr of traumatized teeth. Oral Surg Oral Med Oral Pathol No. 259). 1966;21:100-112. 105. Bhaskar SN, Brady JM, Getter L, et al: Biodegradable ceramic . Steiner JC, Van Hassel HJ: Experimental root apesillcation in implants in bone: electron and light microscopic analysis. Oral primates. Oral Surg Oral Med Oral Pathol 197];37:409-415. Surg Oral Med Oral Palhol 197];32:336-345. . Schroder U, Granath LE: Early reaction of intact human teeth 106. Koenigs JF, Heller AL, Brilliant JD, et af Induced apical clo- to calcium hydroxide following experimental pulpotomy and sure of permanent teeth in adult primates using a resorbable its significance to the development of a hard ussue barrier. form of tricalcium phosphate ceramic. J Endod 1975;1:102- 106. Odontol Rev 1971;22:379-395. Tronstad L, Andreasen JO, Hasselgren G, et al: pH changes 107. Roberts SC Jr, Brilliant JD: Tricalcium phosphate as an ad- in dental tissues after root canal filling with calcium hydroxide. junct to apical closure in pulpless pertiianenc teeth. J Endod J Endod \9?.\:l.il-2\. 1975;1:263-269. Javelet J, forabinejad M, Baklaijd LK: Comparison of two lOK. Coviello J, Brilliant JD: A preliminary clinical study on the
• Iniernäüötial Volume ¿\ Number 7/1990 597 Endodontics
use of triciilciuni phosphale as an apical barrier. J Endod root canal with dentin chip.i in monkey leelli subji-'t^le'J to pulp- 1975:5:6-1?. ectomy. Oral Surg Oral Med Oral Palliol ¡97tí:45:297-3Ü4. 109. Dimashkieh MR: The problem of the open apex - a new ap- 116. Claylon RJ: The Periapical Tissue Response lo and ihe Sealing proach: oxidized regenerated celltilose lechniqite. J Br Endod Ahilily of Apically Packed Denlin Shamigs. thesis. Chicago, Sac 1977;1O:9-I6. Loyola Univcrsily, May 1973. 110. Rossmeisl R, Reader A, Melfi R, et al: A sludy of ñ-eeze-dried 117. Oswald RJ, Friedman CE: Periapical response lo dentin fill- (lyophilized) cortical bone used as an apical barrier in aduli ing.s. Oral Sura Oral Med Oral Palhot 1980:49:344-355. monkey teeth. J Endod 1982:8:219-226. 118. WeisenseeIJA Jr. Hicks ML. Pelleu GBJr: Calcium hydroxide 111. Rossmei.sl R, Reader A, Melfl R, et al: A study of free/.E-dried as an apical barrier. J Endod 1987:13:1-5. dentin used as an apical barrier in adult monkey teeth. Orul 119 Frank AL: Calcium hydroxide: Ihe ultimate medication. Dem Surg Oral Med Oral Ptilhol I9R2;53:3O3-31O. din Norlh Am 1979;23:ö9l-703. 112. Chalmers J: Transplantation immunity in bone homografting. 120. Cvek M: Clinical procedures promoting apical closure and J Bone Joiit! Smg 1959:41:160-179. arrest of external rool lesorption in non-vital permanent in- 113. Burwell RG. Studies in transplantation of bone: ihe capacity cisors, in Grossman L (ed): Tran.saclion.'s of the Fiflh inlerna- or Tresh and treated homogiafts of bone to evoke transplan- linnat Conference an Endodomies. Philadelphia, LJniversily of tation immunity. J Bone Joinl Siirg 1963:45:386-401. Pennsylvania Press, 1973, pp 30-44. 114. Gollmer L: The use of dentin debris as a root canal filling Im 121. Morse DR: One-visit endodontics. Hatiaii Dcnl J 1987: /OrMod 1937:23:101-102. I8(ll):12-i4. G 115. Tronstad L: Tissue reactions following apica) plugging of the
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598 Quintessence International Vnli'-v° rn^ hjumbcr 7/1990