Current and potential pulp therapies for primary and young


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Current and potential pulp therapies for primary and young

  1. 1. Journal of Dentistry Journal of Dentistry 28 (2000) 153–161 Review Current and potential pulp therapies for primary and young permanent teeth D.M. Ranly a,*, F. Garcia-Godoy ba Department of Pediatric Dentistry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-7888, USAb Department of Restorative Dentistry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284-7888, USA Received 1 April 1999; received in revised form 25 June 1999; accepted 10 September 1999Abstract Objectives: This paper aims to alert the dental practitioner to the rapidly evolving therapies for treating the pulps of primary and youngpermanent teeth. Data sources: Experimental research on animals, clinical studies and case reports. Study selection: Indirect pulp capping, direct pulp capping, pulpotomies, and pulpectomies are standard procedures for treating primaryteeth. However, direct pulp capping, heretofore not very successful, is being revisited. Based on studies in animals and clinical findings inhumans, there has been a movement in pediatric dentistry to find alternatives to formocresol and calcium hydroxide for pulpotomy therapy.Venues range from eradication by cautery to the possibility of healing with growth factors. New studies with iodoform paste for pulpectomiesare confirming the success rates of previous publications. The new dental adhesives are being tested as agents for direct pulp capping, as wellas partial and complete pulptomy protocols. Conclusions: More thought is being given by clinicians to preserving pulp, either through more ambitious indirect pulp therapy or partialpulpotomy. Formocresol and calcium hydroxide pulpotomies, while still popular, may soon be challenged by other chemical treatments,electrocautery or stimulation of reparative dentine by growth factors. Iodoform pastes are promising easier and more successful pulpectomytherapy. Total etch direct bonding materials could soon transform direct pulp capping, as well as partial and complete pulpotomy protocols.᭧ 2000 Elsevier Science Ltd. All rights reserved.Keywords: Current pulp therapies; Potential pulp therapies; Primary teeth; Young permanent teeth Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 2. Indirect pulp therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 2.1. The past . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 2.2. The future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 3. Direct pulp capping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 3.1. The past . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 3.2. The future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 3.2.1. Calcium hydroxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 3.2.2. Direct bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 4. Pulpotomy therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 4.1. The past . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 4.2. Current alternative modalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 4.3. The future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 5. Pulpectomy therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 5.1. The past . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 5.2. The future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 * Corresponding author. Tel.: ϩ1-210-567-3553. E-mail address: (D.M. Ranly).0300-5712/00/$ - see front matter ᭧ 2000 Elsevier Science Ltd. All rights reserved.PII: S0300-571 2(99)00065-2
  2. 2. 154 D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–1611. Introduction investigators estimated from a separate histologic evalua- tion that 75% of the teeth selected for indirect pulp therapy This article will review current modalities for the treat- would have been exposed if all carious dentine werement of pulps of primary and young permanent teeth and removed. Despite the advanced state of the disease in thedescribe new and exciting therapies that might supplant majority of these teeth, only 3% of 475 teeth treated indir-them in the future. Over the years, pulp treatment of primary ectly exhibited frank clinical failure. Unfortunately, thisand young permanent teeth have become so dissimilar that seminal study was reported only in abstract form andtheir descriptions are rigidly delimited in textbooks and never published in a peer-reviewed journal. However, itreview articles. Classically, for example, a pulpotomy in a does suggest that clinicians should not so aggressivelyyoung permanent tooth is undertaken to promote apexogen- leap from deep caries removal into pulpotomy therapy.esis; under these conditions, retention of the vitality of the Perhaps a bias toward removing all unsound dentine artifi-radicular pulp is imperative. In contrast, the pulpotomized cially expands the number of primary teeth that dailyprimary tooth is commonly treated with formocresol (FC), a receive more involved treatment. In this vein, Coll andcaustic formulation that kills tissues. However, innovations Foaoq [7] recently urged that the use of indirect pulp ther-in materials and advances in biology suggest that there may apy in primary teeth be expanded.soon be a convergence of therapies for teeth of either denti-tion needing pulp treatment. For this reason, we will depart 2.2. The futurefrom tradition and add some thoughts about young perma-nent teeth to our discussion of pulp therapy for primary Research has demonstrated that the capping agent used inteeth. an indirect pulp treatment is immaterial as long as it seals the carious dentine from oral fluids [2]. This mode of ther- apy is essentially passive. Provided the inflammation is not2. Indirect pulp therapy too severe, nutrient deprivation inhibits further bacterial metabolism and the pulp is able to recover. Unfortunately, Giving a pulp the opportunity to recover from the toxins no therapy exists for more advanced disease states.of dental caries by judiciously removing infected dentine Dentistry needs a way to actively treat carious dentine inand isolating the remaining carious lesion from oral fluids situ. We suggest that the direct treatment of diseased dentinewith a restorative material is now an accepted treatment for with agents that neutralize toxins, stifle microbes andbadly decayed primary and permanent teeth [1,2]. Clinical mollify pulp inflammation is an objective second only tostudies have shown that when a pulp is “affected”, but not decay prevention in worthiness. To be able to arrest pulp“infected”, the resultant pulpitis can be reversed [3]. pathology without reverting to pulp removal supercedes allAnother positive response is the deposition of secondary of the other modalities we will discuss in this article.or reparative dentine beneath the affected zone [4]. Leksell Although Massler felt in 1958 [8] that sterilization of deepet al. [5] have determined that a slower, “stepwise” excava- carious dentine as an alternative to pulp exposure was nearlytion protocol in deeply carious permanent teeth resulted in realized, events since have not proved him prophetic. Wesignificantly fewer pulp exposures. hope that researchers in the 21st century will address the Indirect pulp therapy in primary teeth is probably less most important shortcoming of dentistry—our inability tocommon than in permanent teeth. There are probably promote healing of the infected pulp.several reasons for this. First, pulp exposure resultingfrom aggressive dentine removal is easier to resolve inprimary teeth; a pulpotomy treatment in a primary tooth is 3. Direct pulp cappingless complex and costly than root canal therapy in a perma-nent tooth. Secondly, the thinner dentine layer in primary Direct pulp capping of teeth exposed during cariesteeth necessitates a higher degree of clinical judgement removal has not been viewed as mainstream treatment forabout the thickness of the remaining carious dentine and either primary or permanent teeth [9]. Stanley and Cox arehow closely it approximates the pulp. And thirdly, behavior at the forefront of a movement to disprove the axiom “themanagement considerations perhaps tilt the choice to some- exposed pulp is a doomed organ”. They wish us to considerthing perceived to be definitive, like a pulpotomy, rather pulp as a tissue with many more regenerative powers thanthan the uncertainty of an ambitious indirect pulp cap. has been traditionally held.2.1. The past 3.1. The past The pulps of primary teeth have been shown to be quite The introduction of inorganic calcium hydroxide (CH) toresilient, and the few studies that have weighed the recovery dentistry spawned a biologic revolution [10]. Because CHof indirectly treated primary teeth have been encouraging. can elicit dentine bridge formation when applied to pulpThe most comprehensive evaluation was carried out at the tissue, pulp capping as a modality became feasible. At theEastman Dental Center in the early 1960s [6]. The same time, the very properties of CH, which provoke
  3. 3. D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161 155healing, can also elicit untoward reactions [11]. Attitudes of meant that less of the pulp was encroached upon by newclinicians in response to these side effects, justified or not, dentine. These investigators found no evidence of internalhave stalled the acceptance of CH as a universal inductor of resorption within the study period of 63 days. In our estima-reparative bridge formation. This is particularly true as it tion, the use of CH cements on non-inflamed primary pulpsapplies to pulp capping in primary teeth. is an acceptable treatment. When pulps of primary teeth are minutely exposed during For those willing to try CH cements on cariously exposedcaries removal—or even when they are exposed iatrogeni- primary teeth, the prospects for success would probablycally or by trauma—most dentist opt for a pulpotomy. The benefit from the following protocol: more extensive debri-reluctance to cap the pulp with CH under any circumstance dement and absolute hemostasis. The latter might beis the fear that it will promote internal resorption. While it is prompted with the use of an astringent, as recommendedtrue that CH pulpotomy has fallen from favor because of the by Stanley [9]. The former might be obtained with sodiumhigh incidence of internal resorption [12], there is no hypochlorite as an irrigant (as suggested by Cox for totalevidence, of which we are aware, that demonstrates that etch bonding pulp treatment [15]) or by frank tissue excisionthe application of CH to coronal pulp will automatically (as suggested by Cvek [16] for the treatment of traumaticelicit a similar response. It is our opinion that many primary pulp exposures). Mechanical removal of infected tissue mayteeth are needlessly pulpotomized because of a generaliza- be the only means currently at our disposal, since results oftion. attempts [17,18] to quell experimental pulp inflammation, There are two conditions that might favor internal resorp- while provocative, have not been definitive.tion in pulpotomies but not in pulp caps: geometry andinflammation. First, the ratio of surface area of tissue in 3.2.2. Direct bondingcontact with CH relative to the remaining tissue volume is Recent advances in total etch direct bonding have evokedconsiderably higher in the case of a pulpotomy than in a an interest in applications for pulp therapy. The key compo-pulp capping. If, by itself, CH can elicit side effects, it is nent of the system is the multipurpose dentine bondingmore likely to do it in narrow pulp canals. Second, pulpo- adhesive, which, when it infiltrates into acid etched dentine,tomies are performed on carious teeth with inflamed pulps, forms an impermeable hybrid layer. Several groups havewhereas, in pulp capping, this may not be the situation. The investigated the responses of non-exposed and exposednegative actions of CH may reflect as much its inability to pulp to dentine bonding systems and have proposed themquell inflammation, as its ability to stimulate on its own. for pulp capping [15,19,20]. Based on preliminary findings, This thesis seems to be borne out by the findings of Kopel [21] strongly advocated their adoption as cappingSawusch [13]. In a pulp capping study using inorganic CH agents for primary teeth.and Dycal he reported a failure rate of 13% and 7%, respec- The attractiveness of these systems is that a polymerictively, in teeth where radiographic evidence indicated ques- film can be layered over an exposure site without displacingtionable carious exposures, but a failure rate of 29% and pulp tissue and onto surrounding dentine where it permeates41% when teeth were classified as definitely exposed. Prior the tubules. Furthermore, these adhesives are hydrophilic,to capping, the exposure was debrided with either saline or meaning that dentine and pulp need not be dehydrated prioreugenol. We conclude from this and other studies that extant to their application. The adhesive film is cured by light, andinflammation amplifies CH failures, and until it can be then acts as a barrier as a composite resin is gently spreadmoderated, direct pulp capping of primary teeth with CH over the pulp onto the surrounding dentine. After theshould be restricted to mechanical exposures. composite resin is cured, the exposure is sealed against microleakage.3.2. The future Provided dentine adhesives exhibit favorable biologic properties, the advantages of this system are obvious.3.2.1. Calcium hydroxide First, the primer and dentine adhesive work in a wet envir- CH may have a rebirth in the form of hard-setting or light onment, a property that must surely reduce the potential forcured products. According to Stanley [9], inorganic CH, dehydration injury. And secondly, these hydrophilic adhe-with its very basic pH, creates zones of obliteration and sives apparently flow well over the wet pulp and form acoagulation necrosis superficial to the deeper zones where continuous seal onto the dentine. And thirdly, this prelimin-reparative dentine ultimately begins. Thus in the process of ary covering helps prevent the displacement of compositeinitiating repair, CH injures the pulp. The lower pH CH into the pulp chamber. However, despite these theoreticalproducts such as Dycal may avoid major tissue damage attributes, solid evidence is necessary before they can beand stimulate reparative dentine more directly. In studies recommended as pulp capping agents. As a prerequisite,on non-inflamed primary canines, Turner et al [14] found the dental adhesive, or the primer, must not be cytotoxic;that pulps directly capped with inorganic CH differed from at a minimum, they must be at least neutral with respect tothose treated with hard-setting products by the amount of living cells. And as a bonus, the formulation should benecrosis and thickness of the dentine bridge. The cements antimicrobial and have an ability to stimulate reparativewere less injurious and their bridges were thinner. This dentine like CH.
  4. 4. 156 D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161 Whether dentine adhesives are toxic, neutral or inductive results are encouraging, it must be emphasized that theseof reparative dentine is important in the light of previous studies were relatively short-term.findings. Several investigators have theorized that pulp irri- Findings from histologic studies in primates have gener-tation following placement of a restoration is most often the ated controversy [15,29–32], while those in humans haveresult of marginal microleakage [22,23] and not the materi- revealed some significant deficits [33–35].als per se. Substantiating these earlier conclusions, Cox et In the majority of studies with primates, exposed pulpsal. [24] have demonstrated that pulps of primates exposed capped using the total etch procedure and dentine bondingdirectly to a variety of restorative materials respond favor- agents underwent a typical healing cascade which culmi-ably, provided that there is no microleakage. Furthermore, nated in some degree of dentine deposition [15,29–31,36].silica cement, zinc phosphate cement, a hard-setting CH However, one study reported disastrous results with thesecement and a composite, all initiated dentine bridging. agents, and the authors stated flatly that their use in vitalOnly amalgam failed to stimulate reparative dentine, pulp capping is contraindicated [32]. Unfortunately, thealthough inflammation abated with time. These investiga- same protocols and materials were not used in all studies,tors concluded that pulp responds favorably to capping with so that any sweeping conclusion about the state of the art isany number of materials, provided bacterial contamination far too prevented. They also speculated that some degree of irri- Histologic studies of human teeth capped directly withtation is necessary to incite dentine formation, something dentine bonding agents suggest that they possess less recup-that amalgam did not provide. The failure of dentine adhe- erative powers than those of primates. Mechanicallysive to stimulate dentine would not necessarily rule it out as exposed primary teeth demonstrated microabscesses adja-a capping agent, but one might question the long-term cent to the exposure site, with no dentine bridging in anycompatibility of pulp cells against an artificial surface. specimens [34]. Pulps of sound premolars, exposed and Because acid in some form is used in dentine adhesive capped with an adhesive system, exhibited a persistentsystems to remove the smear layer and open dentine tubules, mild inflammation and no evidence of repair after severalpulp tissue must tolerate an acidic environment in order for months [33]. In another study on sound premolars, resindirect capping to succeed. Snuggs et al. [25] have provided particulates were observed in the pulp [35]. They appearedevidence to suggest that pulp does indeed have a high toler- to have triggered a foreign body response and preventedance for acidic conditions. When monkey teeth were calcific bridge formation. Inokoshi et al. [19] found chronicdirectly capped with silicate or zinc phosphate cements ulcerative pulpitis in the teeth they capped. In contrast,and sealed with ZOE to exclude bacteria, an inherent heal- Katoh [37] found pulp irritation to be minimal, withing capacity of cell reorganization and dentineal bridging evidence of dentine bridging in 95% of cases.was observed. The discrepancies between species and laboratories may An overall statement about the antibacterial properties of be related to protocols, materials or both. Cox, who reportsdentine adhesives is impossible at this time. The current favorable results in primates, contends that hemostasis is theproducts variably use cleaners, primers, sealers and etchants crucial step, and that it is obtained best with sodium hypo-preparatory to adhesives. Any or all could be antibacterial. chlorite (NaOCl) [15]. This solution dissolves tissue and hasHowever, an in vitro study by Emilson and Bergenholtz [26] been evaluated as an agent for pulp amputation [38–40].found that antibacterial properties were exhibited only by Therefore, its attributes, other than hemorrhage control,cleaners, primers and etchants. Of the four systems they may be its ability to purge bacteria, superficial inflamedevaluated, none of the cured adhesives demonstrated anti- tissue and dentine debris from the exposure site.bacterial effects. This study suggests that the antibacterial Recently, reports for several studies have beenproperties of dentine adhesives will be short-term, unless controversial, with some showing severe responses [41],efforts are made to incorporate releasable antibacterials. others reporting minimal to moderate reactions [42], while Some of the biologic properties of dentine adhesives are others observed excellent results including dentine bridgecurrently being examined in vivo. From preliminary animal after etching and covering the pulp with dentine adhesivesand human studies evaluated by clinical criteria, the accep- [43–46]. Another study reported that capping the pulp withtance of direct bonding by the pulp has been encouraging. a polyacid-modified resin-based composite (compomer)Unfortunately, the histologic response of pulp to these mate- also produced satisfactory pulpal response [47]. From arials is less clear-cut. clinical and radiographic standpoint, dentine adhesives Clinical studies on the use of dental adhesives as direct used as a direct pulp capping material have also beenpulp capping agents in human permanent [20,27] and reported as successful [48].primary teeth [28] have demonstrated short-term success. Because of these controversial results, at present weHeitmann and Unterbrink [27] reported no symptoms in cannot recommend dentine adhesives for direct pulpall eight teeth they treated; Kashiwada and Takagi [20] capping until more favorable human studies have beenhad four failures out of 64 direct capping procedures; and reported. One of the shortcomings of current testing inAraujo et al [28] observed no adverse clinical or radio- monkeys and humans is the shotgun approach to testinggraphic findings in 15 primary molars. While the overall products. Because components and protocols are so
  5. 5. D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161 157different, negative findings do not necessarily condemn clotting, the internal resorption of primary teeth was stilldental adhesives in general as direct capping agents. Before observed [57].more clinical trials are undertaken, we suggest that the most In an attempt to minimize the cutting of major pulpbiologically acceptable dental materials and ancillary agents vessels and resultant blood clots, Schroeder et al. [58]be determined first in vitro. As a step in that direction, a performed partial pulptomies on primary teeth. Internalrecent study determined that the components of three one- resorption was apparently reduced, but the overall successbottle adhesive systems were highly cytopathic to an odon- rate was only about 80%. This rate of success is certainly notoblast cell line [49]. Such assays can eliminate less promis- better than that reported for FC, and the procedure is moreing candidates, and in this way, the number of variables in demanding. It does, however, eliminate the use of a toxicclinical trials can be minimized and the findings more easily agent.interpreted. 4.2. Current alternative modalities The failure of CH and the desire to find a drug less toxic4. Pulpotomy therapy than FC initiated an extensive search for alternative pulpot- omy agents in the 1970s [51]. The efforts of a considerable4.1. The past number of investigators have culminated in a spectrum of ways to pulpotomize primary teeth. FC has long been the standard pulpotomy agent in One of the early attempts to reduce FC toxicity was toprimary teeth, and CH the standard for immature permanent lower its concentration. Based on preliminary in vitroteeth [50]. While the rationale for the use of FC is not clear, analyses [59], a 1/5 dilution was selected and subjected toit presumably fixes affected and infected radicular tissue so clinical trials [60]. It was found to be as effective as full-that a chronic inflammation replaces an acute inflammation. strength preparations. In an attempt to further reduce FCIt is the intent of the fomocresol pulpotomy that pulp toxicity, glutaraldehyde (GA) was advocated as an alterna-remains in a metastable condition until the tooth is exfo- tive to formaldehyde because it is a true cross-linking fixa-liated. Even under this dubious rationale, the success rates tive [61]. It also demonstrates less antigenicity, self-limitingwith FC have been clinically acceptable. penetration, and reduced toxicity [62]. Clinical trials in In recent years, voices have been raised against FC primary and permanent teeth have been promising [63–because of its toxicity [51], and it has been banned in at 65]. The rationale for GA is the establishment of a biocom-least one country. However, the FC pulpotomy technique is patible seal over the amputated pulp, which separates itstill being taught in virtually every dental school in the from the adjacent base.United States [52] and in many other countries. For better Ferric sulfate (FS) has gained support as a pulpotomyor for worse, FC promises to be with us for some time. agent in primary teeth although the original rationale for CH is considerably less harsh on pulp tissue than FC its introduction has been forgotten. It was first investigated[53,54]. Under optimal conditions it can stimulate a dentine as a hemostatic agent preparatory to the placement of CHbridge, but it is not ordinarily used for that purpose in a over amputated pulp [66]. The intent was to determine ifpulpotomy procedure on permanent teeth. Instead, it serves hemorrhage control improved the efficacy of CH, sinceto maintain the vitality of radicular tissue until apexogenesis earlier investigators speculated that the failures of CHis complete. Once the apex is closed, a root canal is were due to the persistence of blood clots between it andperformed. The practice of obturating the canals immedi- pulp tissue [57]. For unknown reasons, subsequent studiesately upon root completion is based on anecdotal evidence have evaluated FS alone [67,68], and not as an adjunct tothat CH will precipitate dystrophic calcification in the CH, and its success rate has approximated that of FC. Fromcanals and prevent endodontics later, if it should be needed. what we know, it does not stimulate reparative dentine, andThe negative impact of CH in a classic pulpotomy, if real, it does not improve pulp responses compared to FC [69,70].may result from too little pulp tissue confined with too much Perhaps the mechanisms of action of FS are to prevent clotchemical. When partial pulpotomies were performed, with formation—and its attendant inflammatory cascade—andthe objective of removing only infected tissue, dentine brid- to precipitate a protein barrier at the amputation site.ging was stimulated in the coronal area, and the canals were A widely divergent approach to pulpotomies in primaryfree of dystrophic calcification [55]. teeth has also evolved in recent years. Instead of devitaliz- For a time, CH was touted as an alternative to FC for ing pulp with a chemical, electrocautery is used to burn andpulpotomies in primary teeth [56], but too often it was coagulate radicular tissue. A pulp so treated displays theobserved to stimulate internal resorption rather than dentine remnants of a burn—coagulated protein, necrosis andformation [12], and its popularity has waned. The observed inflammation [71]. Clinically, the success rate of electro-resorption has been ascribed to a blood clot intervening cautery has been reported high [72], similar to FC [73],between the chemical and pulp tissue and not to CH per and very poor [74].se. However, even with stringent conditions taken to avoid Lasers have been suggested as a more sophisticated
  6. 6. 158 D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161instrument for devitalizing pulps, but in a recent studies on We have learned that there is a family of proteins that hashuman canines, the histologic pictures of FC and laser-trea- bone inductive properties, and BMP is a generic term forted pulps were not significantly different, and the pretext for this family.further laser research was only the avoidance of FC [75]. BMPs are members of a highly conserved family of signalCertainly in the pulps of dogs, irradiation with laser caused molecules that have been recycled during evolution tocarbonization, necrosis, inflammation, edema and hemor- mediate interactions between tissues during embryonicrhage—with little evidence of repair [76]. development. For this reason, BMP is a misleading nomen- As mentioned previously, Stanley is a strong propo- clature in that it implies a single gene product responsiblenent of CH for pulp capping and pulpotomies [9]. He for bone formation, when, instead, each probably accountsavers that the negative side effects of inorganic CH for multifunctional gene products expressed throughouthave been eliminated in the lower pH hard-setting ontogeny. Because the osteogenic role was discovered incements. He suggests that the internal resorption and mammals and the embryonic role in phylogeneticallythe dystrophic calcification seen in pulpotomized lower organisms, a confusing multiplicity of names hasprimary and permanent teeth, respectively, are less arisen.likely to occur with commercial CH preparations. To establish some order to the terminology, the BMPHowever, these claims have not been adequately family of proteins has been renamed the DVR(decapenta-substantiated. Only one small, short-term clinical study plegic-Vg-related) family, based on the first two members tousing a CH cement in primary teeth has been reported be identified—Drosophila decapentaplegic and Xenopus[77]. Because CH does have favorable properties, Vg1. Table 1 of Ref. [79] lists the family by DVR, BMPperhaps pulpotomies with hard-setting cements should and osteogenic protein (OP) names. The DVR familybe revisited. belongs to the much larger transforming growth factor b (TGF-b) superfamily.4.3. The future From our yet inchoate knowledge, the implications of BMPs to dentistry are nonetheless enormous. The availabil- Interestingly, in the future, pulpotomies for primary and ity of commercial BMPs to predictably induce bone forma-permanent teeth may be handled in exactly the same way. tion in orthopedic, oral and periodontal surgery will beAdvances in material and biological sciences offer us at momentous [80]. Shortly after his original report, Uristleast two therapeutic approaches, either of which could [81] observed that demineralized dentine also had inductivebecome common to both dentitions. From material sciences properties, and since then it has been demonstrated thatwe have seen the development of dentine adhesives, which BMP from both bone and dentine will promote dentineogen-we have already discussed in another context. From biolo- esis [82–84]. Thus, the implications for pulp therapy aregical research we have seen an explosion of knowledge immense. If BMPs can be packaged in a form suitable forabout growth factors that induce bone and dentine. The clinical usage, dentists might at last have a true biologicalpotential to acquire pulp therapeutics from these burgeoning pulp capping and pulpotomy agent. Table 2 of Ref. [79] listsfields is worth discussing. the known BMPs and their actions when implanted into If dentine adhesives can be developed for direct pulp receptive tissue. Osteogenic potential was evaluated usingcapping, then there is no reason that they cannot be used subcutaneous implants in rats; pulp responses were deter-for pulpotomies. In fact, the chances for success should mined in dog and primate teeth.improve in the latter, simply because the purpose of pulp The data from the several pulp studies summarized inamputation is to reach a level of healthy pulp. With diseased Table 2 of Ref. [79] suggest that a number of BMPs aretissue removed, the response of the remaining pulp should capable of inducing reparative dentine. This should not bebe more favorable. Although we do not know of any studies surprising since BMPs probably play a regulatory role inin this area, it does seem a logical progression of the pulp cell differentiation [85–87] and human toothtechnology. Just as for direct capping, we urge a stepwise morphogenesis [88]. In addition, receptors for them haveapproach in evaluating dentine adhesive for pulpotomies. been identified in human dental pulp [89]. Even more exciting than dental adhesives are the recent As expected, demineralized bone and dentine haveadvances in the field of bone morphogenetic proteins proved inductive of the same tissues, but more impor-(BMPs). The discovery of this family of growth factors tantly, recombinant human BMPs have also been shownsprang from the observation by Urist [78] that deminera- to be effective. Progress from crude preparations to purelized bone matrix could stimulate new bone formation when protein has been rapid. Fadavi et al. [90] dressed pulpo-implanted in ectopic sites such as muscle. Urist concluded tomized monkey teeth with freeze-dried bone and Naka-rightly that bone matrix contains a factor capable of shima [83] used dentine matrix to treat amputated pulpsautoinduction, and he named it bone morphogenetic of dogs. Narrowing the focus further, crude BMPprotein. Because these factors exist in such minute prepared from bovine bone was used to treat pulpto-quantities, it was not until the development of molecular mized dog teeth [82,91,92]. The latter studies reportedbiology that their physiologic roles could be explored. the sequential induction of osteo- and tubular dentine.
  7. 7. D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161 159The preparations of BMP were ill-defined; presumably therapy in permanent teeth, might be adapted to the needsthey included BMP-2, BMP-3, and BMP-7 (OP1). of primary teeth [101,102]. Garcia-Godoy [103], confirmed While BMP preparations from bovine or human bone the efficacy of this preparation. Primary teeth with signifi-would not be feasible for human teeth, molecular biology cant infection, furcal involvement and mobility were routi-techniques have fortunately circumvented the necessity of nely salvaged and retained. The rate of healing was notable.isolating BMP from bone. Recombinant human BMP-2, The material is clinically forgiving. After the canals areBMP-4 and OP-1 have been purified and characterized, prepared, the paste can be easily injected into them with aand all have shown dentine inductive potential in host CR syringe. Filling to the apices is unusual and apparentlyteeth [93,94]. Most importantly, the response to hOP-1 in unnecessary. What is crucial is the placement of the pasteprimate teeth was dose dependent, a property never before over the floor of the chamber, in order to ensure that theattributed to a pulp agent. Equally exciting is the finding that auxiliary canals traversing to the furcation are medicated.reparative dentine can be stimulated transdentine by OP-1 in Should the paste be expressed into extradental spaces, it isa dose dependent manner. The demonstration that reparative resorbed within a week or two. Evidence of significant heal-dentine can be induced by direct or indirect contact with a ing occurs within weeks.biologic agent—and its thickness determined by dose— A newer preparation, Vitapex, a mixture of iodoform andelevates pulp therapy to a new level. Clearly, this regenera- CH, is now available in North America. Preliminary studiestive approach, if successful, would transcend all other suggest that it, too, is efficacious for pulpectomies inmodalities. primary teeth [104]. We are now entering an era when commercially availablerecombinant human BMPs will be available for experimen-tation and clinical trials. Several authors have encouraged 6. Conclusionthe evaluation of these factors as new modalities for pulp The old standbys of pulp therapy, FC, CH, and ZOE aretherapy [62,95,96]. It is exciting to think that someday we being superceded by new agents. On the horizon are biolo-might treat a pulpotomized primary or permanent molar gics and newer materials that may completely transform ourwith growth factors and predictably induce sound dentine whole philosophy of treatment. We seem to be on the brinkbridges, leaving the radicular tissue completely enclosed in of an era when a diseased pulp can be a saved pulp.healthy dentine. Primary teeth would be free of inflamma-tion and could exfoliate normally; the need for root canaltherapy in permanent teeth would be eliminated. References [1] Aponte AJ, Hartsook JT, Crowly MC. Indirect pulp capping success5. Pulpectomy therapy verified. ASDC Journal of Dentistry for Children 1966;33(3):164–6. [2] Stark MM, Nicholson RJ, Soelberg KB. Direct and indirect pulp5.1. The past capping. Dental Clinics of North America 1976;1:115–26. [3] Stanley HR. Pulpal responses to dental techniques and materials. Endodontic therapy for primary teeth has long been advo- Dental Clinics of North America 1971;15(1): 115–26. [4] Kerkhove Jr VC, Herman SC, Klein AI, McDonald RE. A clinicalcated when the criteria for a classical pulpotomy treatment and television densitometric evaluation of the indirect pulp cappingcannot be met [97]. The procedure involves debridement technique. ASDC Journal of Dentistry for Children 1967;34:192–and enlargement of the canals with graded files prior to 201.obturation with ZOE [98]. The latter should be unfilled so [5] Leksell E, Ridell K, Cvek M, Mejare I. Pulp exposure after stepwisethat they will resorb in synchrony with the roots. Unfortu- versus direct complete excavation of deep carious lesions in young posterior permanent teeth. Endodontics and Dental Traumatologynately, even pure ZOE cement is resistant to foreign body 1996;12:192–6.giant cells, and very often fragments of cement can be seen [6] Hawes RR, DiMaggio JJ, Sayegh F. Evaluation of direct and indirectat the site of a pulpectomized tooth that has exfoliated [99]. pulp capping. Journal of Dental Research 1964;43(5):808. In addition to its bioincompatibility, ZOE is not particu- [7] Coll J, Foaoq N. Indirect pulp therapy—an alternative to pulpotomylarly antibacterial once it has set. This is a glaring deficit for deep caries. 52nd Annual Session, American Academy of Pedia- tric Dentistry, 1999.because it has been shown that the root canals of primary [8] Massler M. In: Cheraskin E, editor. Pulp protection and preservation,teeth are fenestrated and torturous [100], and it is unlikely Practical dental monographsChicago: The Year Book Publishers,that they could ever be filed and obturated in the traditional 1958. p. 1–47.sense. What is needed is a filling material that is resorbable [9] Stanley HR. Pulp capping: conserving the dental pulp—can it beand has long lasting antibacterial properties. Iodoform done? Is it worth it? Oral Surgery, Oral Medicine and Oral Pathology 1989;68:628–39.pastes seem to fulfill these requirements. [10] Hermann BW. Calciumhydroxyd als mittel zum behandeln und fullen von wurzekanalen (Dissertation). Wurzburg: 1920.5.2. The future [11] Schroeder U. On internal dentinee resorption in deciduous molars treated by pulpotomy and capped with calcium hydroxide. Odonto- Rifkin first demonstrated that a commercial preparation, logica Revy 1971;22:179–88.Kri paste, which was originally developed for root canal [12] Magnusson B. Therapeutic pulpotomy in primary molars—clinical
  8. 8. 160 D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161 and histological follow-up. I. Calcium hydroxide paste as a wound dental pulp to an etch technique in vivo. American Journal of Dentis- dressing. Odontologica Revy 1970;21:415–31. try 1998;10:S35–S44. [13] Sawusch RH. Dycal capping of exposed pulps in primary teeth. [36] Cox CF, Chain MC. Characterization of the cell healing sequence in ASDC Journal of Dentistry for Children 1963;30(3):141–9. exposed monkey pulps when capped with various adhesive systems. [14] Turner CT, Courts FJ, Stanley HR. A histological comparison of Journal of Dental Research 1996;75(SI):280. direct pulp capping agents in primary canines. ASDC Journal of [37] Katoh Y. Clinico-pathological study on pulp irritation of adhesive Dentistry for Children 1987;54(6):423–8. resinous materials. (Report 1) Histopathological change of the pulp [15] Cox CF, Hafez AA, Akimoto N, Otsuki M, Suzuki S, Tarim B. tissue in direct capping. Adhesive Dentistry 1993;11:199–211. Biocompatibility of primer, adhesive and resin composite systems [38] Sudo C. A study on partial pulp removal (pulpotomy) using NaOCl on non-exposed and exposed pulps of non-human primate teeth. (sodium hypochlorite). Journal of the Japanese Stomalogical Society American Journal of Dentistry 1998;10:S55–S63. 1959;26:1012–24. [16] Cvek M. A clinical report on partial pulpotomy and capping with [39] Hirota K. A study on partial pulp removal (pulpotomy) using four calcium hydroxide in permanent incisors with complicated crown different tissue solvents. Journal of the Japanese Stomalogical fracture. Journal of Endodontics 1978;4:232–7. Society 1959;26:1588–1603. [17] Yoshiba K, Yoshiba N, Iwaku M. Effects of antibacterial capping [40] Katoh M, Kidokoro S, Kurosu K. A study on the amputation of pulp agents on dental pulps of monkeys mechanically exposed to oral using sodium hydrochlorite (NaOCl). Japanese Journal of Pediatric microflora. Journal of Endodontics 1995;21(1):16–20. Dentistry 1978;16:107–16. [18] Sazak H, Gunday M, Alatli C. Effect of calcium hydroxide and [41] Pameijer C, Stanley H. Pulp capping with total etch and other experi- combinations of Ledermix and calcium hydroxide on inflamed mental methods. Journal of Dental Research 1999;78:219. pulp in dog teeth. Journal of Endodontics 1996;22(9):447–9. [42] Ciavarelli L, Fazio Pd, Scarano A, Piatelli A. Histological analysis [19] Inokoshi S, Fujitani M, Otsuki M, Shimada Y, Hosoda H. Adhesive of direct pulp capping with enamel dentine bonding systems in vivo. resin as a pulp capping agent. Adhesive Dentistry 1990;8:157–62. Journal of Dental Research 1999;78:219. [20] Kashiwada T, Takagi M. New restoration and direct pulp capping [43] Fujitani M, Shibata S, Van Meerbeek B, Yoshida Y, Inokoshi S, systems using adhesive composite resin. Bulletin of the Tokyo Wakasa K, et al. Healing and interfacial ultra-morphology of Medical and Dental University 1991;38:45–52. monkey pulp capped with adhesives. Journal of Dental Research [21] Kopel H. The pulp capping procedure in primary teeth revisited . 1999;78:220. ASDC Journal of Dentistry for Children 1997;65(2):84–5. [44] Katoh Y. Wound healing process of pulp directly capped with adhe- [22] Brannstrom M, Nyborg H. The presence of bacteria in cavities filled sive resins. Journal of Dental Research 1999;78:220. with silicate cement and composite resin materials. Swedish Dental [45] Suzaki T, Katoh Y. Study of 4-META/MMA-TBB resin containing Journal 1971;64:149–55. Ca(OH)2 as direct pulp capping agent. Journal of Dental Research [23] Going RE. Microleakage around dental restorations: a summarizing 1999;78:220. review. Journal of the American Dental Association 1972;84:1349– [46] Ebihara T, Katoh Y. Study of adhesive resins containing Ca(OH)2 as 57. pulp capping agents. Journal of Dental Research 1999;78:220. [24] Cox CF, Keall CL, Keall HJ, Ostro E, Bergenholtz G. Biocompat- [47] Driessen C, Coetzee W, Ligthelm A. A new concept towards direct ibility of surface-sealed dental materials against exposed pulps. Jour- pulp capping using compomer restorative. Journal of Dental nal of Prosthetic Dentistry 1987;57(1):1–8. Research 1999;78:220. [25] Snuggs HM, Cox CF, Powell CS, White KC. Pulpal healing and [48] Boretti R, Lutz F, Krejci I. Successful pulp capping with dentineal dentineal bridge formation in an acidic environment. Quintessence adhesive. Journal of Dental Research 1999;78:368. International 1993;24(7):501–10. [49] Costa CAS, Vaerten MA, Hanks CT. Cytotoxicity of one bottle [26] Emilson C, Bergenholtz G. Antibacterial activity of dentineal bond- adhesive systems. Journal of Dental Research 1999;78(SI):385. ing agents. Quintessence International 1993;24:511–5. [50] McDonald RE, Avery DR. Dentistry for the child and adolescent, 6. [27] Heitmann T, Unterbrink G. Direct pulp capping with a dentineal St Louis: Mosby, 1994. adhesive resin system. Quintessence International 1995;26: [51] Ranly DM. Formocresol toxicity. Current knowledge. Acta Odonto- 765–70. logica Pediatrica 1985;5:93–98. [28] Araujo FB, Barata JS, Garcia-Godoy F. Clinical and radiographic [52] Primosch RE, Blomb TA, Jerrell RG. Primary tooth pulp therapy as evaluation of the use of an adhesive system over primary dental taught in predoctoral pediatric dental programs in the United States. pulps. Journal of Dental Research 1996;75(SI):280. Pediatric Dentistry 1997:118. [29] Akimoto N, Momoi Y, Kohno A, Otsuki M, Suzuki SH, Suzuki S, et [53] Zander HA. Reaction of the pulp to calcium hydroxide. Journal of al. Histologic observation of direct capped pulps with LinerBond-2 Dental Research 1939;18:373–9. adhesive system. Journal of Dental Research 1997;76(SI):78. [54] Boller RJ. Reaction of pulpotomized teeth to zinc oxide and formo- [30] Otsuki M, Tagami J, Kanca III J, Akimoto N, Suzuki SH, cresol-type drugs. ASDC Journal of Dentistry for Children Suzuki S, et al. Histologic evaluation of two Bisco adhesive 1972;39:298–307. systems on exposed pulps. Journal of Dental Research [55] Mejare I, Cvek M. Partial pulpotomy in young permanent teeth with 1997;76(S1):78. deep carious lesions. Endodontics and Dental Traumatology [31] Cox CF. Biologic interaction of adhesive systems with vital dental 1993;9:238–42. pulps. Journal of Dental Research 1997;76:251. [56] Doyle WA, McDonald RE, Mitchell DF. Formocresol versus [32] Pameijer CH, Stanley HR. The disastrous effects of the total etch calcium hydroxide in pulpotomy. ASDC Journal of Dentistry for technique in vital pulp capping in primates. American Journal of Children 1962;29:86–97. Dentistry 1998;11:S45–S54. [57] Schroeder U. A 2-year follow-up of primary molars pulpotomized [33] Pereira JC, Segala AD, Costa CAS. Human pulp response to direct with a gentle technique and capped with calcium hydroxide. Scan- pulp capping with an adhesive system—histologic study. Journal of danavian Journal of Dental Research 1978;39:273–8. Dental Research 1997;76:180. [58] Schroeder U, Szpringer-Nodzak M, Janicha J, Wacinska M, Budny [34] Araujo FB, Barata JS, Costa CAS, Garcia-Godoy F. Clinical, radio- J, Mlosek K. A one-year follow-up of partial pulpotomy and calcium graphical and histological evaluation of direct pulp capping with a hydroxide capping in primary molars. Endodontics and Dental Trau- resin adhesive in primary teeth. Journal of Dental Research matology 1987;3:304–6. 1997;76(SI):179. [59] Straffon LH, Han SS. Effects of varying concentrations of [35] Gwinnett AJ, Tay FR. Early and intermediate time response of the formocresol on RNA synthesis of connective tissue in sponge
  9. 9. D.M. Ranly, F. Garcia-Godoy / Journal of Dentistry 28 (2000) 153–161 161 implants. Oral Surgery, Oral Medicine and Oral Pathology extracted allogeneic dentine on amputated pulps of dogs. Endodon- 1970;29:915–25. tics and Dental Traumatology 1989;5:279–86.[60] Morowa AP, Straffron LH, Han SS, Corpron RE. Clinical evaluation [84] Mizutani H, Mera K, Ueda M, Iwata H. A study of the bone morpho- of pulpotomies using dilute formocresol. ASDC Journal of Dentistry genetic protein derived from bovine demineralized dentine matrix. for Children 1975;42:360–3. Nagoya Journal of Medical Science 1996;59(1/2):37–47.[61] s’Gravenmade EJ. Some biochemical considerations of fixation in [85] Nakashima M. Mitogenic and dentine-inductive effects of crude endodontics. Journal of Endodontics 1974;1:233–7. bone morphogenetic protein from bone and dentine in primary[62] Ranly DM. Pulpotomy therapy in primary teeth: new modalities for adult pulp cell culture. Oral Surgery, Oral Medicine and Oral Pathol- old rationales. Pediatric Dentistry 1994;16:403–9. ogy 1992;73(4):484–9.[63] Garcia-Godoy F. A 42 month clinical evaluation of glutaraldehyde [86] Takeda K, Oida S, Goseki M, Iimura T, Maruoka Y, Amagasa T, et pulpotomies in primary teeth. Journal of Pedodontics 1986;10:148– al. Expression of bone morphogenetic protein genes in human dental 55. pulp cells. Bone 1994;15(5):467.[64] Araujo FB, Ely LB, Pergo AM, Pesce HF. A clinical evaluation [87] Nakashima M, Nagasawa H, Yamada Y, Reddi AH. Regulatory role of of 2% buffered glutaraldehyde in pulpotomies of human decid- transforming growth factor-beta, bone morphogenetic protein-2, and uous teeth: a 24-month study. Brazilian Dental Journal 1995;6(1): protein-4 on gene expression of extracellular matrix proteins and differ- 41–4. entiationofdentalpulpcells.DevelopmentalBiology1994;162(1):18–28.[65] Waly NG. Long-term follow-up of glutaraldehyde pulpotomies in [88] Heikinheimo K. Stage-specific expression of decapentaplegic-Vg- young permanent molars. Egyptian Dental Journal 1994;40(4):927– related genes, 2, 4, and 6 (bone morphogenetic proteins 2, 4, and 32. 6) during human tooth morphogenesis. Journal of Dental Research[66] Landau MJ, Johnsen DC. Pulpal responses to ferric sulfate in 1994;73(3):590–7. monkeys. Journal of Dental Research 1988;67:215. [89] Gu K, Smoke RH, Rutherford RB. Expression of genes for bone[67] Fei A, Udin RD, Johnson R. A clinical study of ferric sulfate as a pulp- morphogenetic proteins and receptors in human dental pulp. otomy agent in primary teeth. Pediatric Dentistry 1991;13:327–33. Archives of Oral Biology 1996;41(10): 919–90.[68] Fuks AB, Holan G, Davis JM, Eidelman E. Ferric sulfate versus [90] Fadavi S, Anderson AW, Punwani IC. Freeze-dried bone in pulpotomy dilute formocresol in pulpotomized primary molars: long-term procedures in monkeys. Journal of Pedodontics 1988;13:108–22. follow up. Pediatric Dentistry 1997;19(5):327–30. [91] Lianjia J, Yuhao G, White FH. Bovine bone morphogenentic[69] Cotes O, Boj JR, Canalda C, Carreras M. Pulpal tissue reaction to protein-induced dentineogenesis. Clinical Orthopedics 1993; formocresol vs. ferric sulfate in pulpotomized rat teeth. Journal of 295:305–12. Clinical Pediatric Dentistry 1997;21(3):247–53. [92] Gao Y, Fang YR, Suwa F, Yoshida S, Yang L, Tanaka A. Induction[70] Fuks AB, Eidelman E, Cleaton-Jones P, Michaeli Y. Pulp response of reparative dentine formation in dogs by bovine bone morphoge- to ferric sulfate, diluted formocresol and IRM in pulpotomized netic protein bound to ceramic dentine. Journal of the Osaka Dental primary baboon teeth. ASDC Journal of Dentistry for Children University 1995;29(1):29–38. 1997;64(4):254–9. [93] Nakashima M. Induction of dentine formation on canine amputated[71] Ruemping DR, Morton TH, Anderson MW. Electrosurgical pulpot- pulp by recombinant human bone morphogenetic proteins (BMP)-2 omy in primates: a comparison with formocresol pulpotomy. Pedia- and -4. Journal of Dental Research 1994;73:1515–22. tric Dentistry 1983;5:14–8. [94] Rutherford RB, Wahle J, Tucker M, Rueger D, Charette M. Induction of[72] Mack RB, Dean JA. Electrosurgical pulpotomy: a retrospective reparative dentinee formation in monkeys by recombinant human human human study. ASDC Journal of Dentistry for Children osteogenic protein-1. Archives of Oral Biology 1993;38:571–6. 1993;60:107–14. [95] Irwin C. Polypeptide growth factors—a role in restorative dentis-[73] Fulkerson BT, Dean JA, Mack RB. Prospective comparison of elec- try?. European Journal of Prosthodontics and Restorative Dentistry trosurgical and formocresol pulpotomy procedures. Journal of 1995;3(5):227–30. Dental Research 1998;77:271. [96] Rutherford B, Fitzgerald M. A new biological approach to vital pulp[74] Fishman SA, Udin RD, Good DL, Rodef F. Success of electro- therapy. Critical Reviews in Oral Biology and Medicine 1995;6(3): fulguration pulpotomies covered by zinc oxide eugenol or 218–29. calcium hydroxide: a clinical study. Pediatric Dentistry [97] Gould JM. Root canal therapy for infected primary molar teeth— 1996;18(5):385–90. preliminary report. ASDC Journal of Dentistry for Children[75] Elliot RD, Burkes EJ, Phillips CL, Roberts MW. CO2 laser and 1972;39:269–73. formocresol pulpotomy effects on human primary pulp. Journal of [98] Goerig AC, Camp JH. Root canal treatment in primary teeth: a Dental Research 1999;78(SI):386. review. Pediatric Dentistry 1983;5:33–7.[76] Jukic S, Anic I, Koba K, Najzar-Fleger D, Matsumoto K. The effect [99] Sadrian R, Coll JA. A long-term followup on the retention rate of of pulpotomy using CO2 and Nd:YAG lasers on dental pulp tissue. zinc oxide eugenol filler after primary tooth pulpectomy. Pediatric International Endodontic Journal 1997;30(3):175–80. Dentistry 1993;15:249–53.[77] Heilig J, Yates J, Siskin M, McKnight J, Turner J. Calcium hydro- [100] Hibbard ED, Ireland RL. Morphology of the root canals of the xide pulpotomy for primary teeth: a clinical study. Journal of the primary molar teeth. ASDC Journal of Dentistry for Children American Dental Association 1984;108:775–8. 1957;24:250–7.[78] Urist M. Bone formation by autoinduction. Science 1965;150:893–9. [101] Rifkin A. A simple, effective, safe technique for the root canal[79] Lyons KM, Jones CM, Hogan BLM. The DVR gene family in treatment of abscessed primary teeth. ASDC Journal of Dentistry embryonic development. Trends in Genetics 1991;7:408–12. for Children 1980;47: 435–41.[80] Lee MB. Bone morphogenetic proteins: background and implica- [102] Rifkin A. The root canal treatment of abscessed primary teeth. A tions for oral reconstruction. Journal Clinical Periodontics three to four-year follow-up. ASDC Journal of Dentistry for Chil- 1997;24(6):355–65. dren 1982;49:428–31.[81] Bang G, Urist MR. Bone induction excavation chambers in matrix of [103] Garcia-Godoy F. Evaluation of an iodoform paste in root canal decalcified dentine. Archives of Surgery 1967;94:781–9. therapy for infected primary teeth. ASDC Journal of Dentistry for[82] Nakashima M. The induction of reparative dentinee in the amputated Children 1987;54:30–4. dental pulp of the dog by bone morphogenentic protein. Archives of [104] Nurko C, Garcia-Godoy F. Evaluation of a calcium hydroxide/iodo- Oral Biology 1990;35:493–7. form paste (Vitapex) in root canal therapy for primary teeth. Journal[83] Nakashima M. Dentine induction by implants of autolyzed antigen- of Clinical Pediatric Dentistry 1999;23:289–94.