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A comparison of the management of pulpal pathosis in deciduous and permanent teeth
A comparisonof the managementof pulpal pathosis in deciduousand permanent teeth Harold Be&, D.D.S., F.A.C.D., P.I.C.D.,” and Alvin A&m Krakow, D.D.S., F.I.C.D.,** Boston, Mass. FORSYTH AND
DENTAL
HARVARD
CENTER,
SCHOOL
TUFTS
OF DENTAL
UNIVERSITY
SCHOOL
OF DENTAL
MEDICINE,
MEDICINE
Endodontic treatment in the adult dentition, as practiced by most endodontists, does whereas endodontic treatment in the not include vital pulp therapy procedures, deciduous teeth, as practiced by most pedodontists, is mostly limited to vital pulp therapy procedures and rarely includes complete root canal therapy. There are many advantages to maintaining pulpless deciduous teeth, and suggestions are presented to assist the clinician in solving the problems of instrumenting and filling these canals. Vital pulp therapy procedures can also enjoy a high success rate in the adult dentition. By combining accurate diagnosis with proper ease selection and treatment techniques, successful vital pulp therapy procedures are predictable. Accordingly, complete root canal therapy can often be avoided in the adult dentition.
I
n reviewing the literature, it becomes apparent that complete endodontic treatment procedures are not usually applied to infected deciduous teeth.1-5 Conversely, vital pulp therapy procedures frequently utilized by the pedodontist are rarely applied to adult permanent teeth by the endodontist. The purpose of this article is to probe the reasons for this and to suggest that, under certain circumstances, there is a role for complete endodontic procedures in the deciduous dentition and, furthermore, that there is also a place for vital pulp therapy in the adult dentition. Regarding complete endodontic procedures in deciduous teeth, although endodontists and pedodontists agree that it is desirable to have the ability to retain these infected deciduous teeth in order to maintain space and function, both have neglected this particular phase of endodontic practice. This reluctance
*Assistant Clinical Professor, Department of Oral Pediatrics, Tufts University School of Dental Medicine; Staff Associate, Forsyth Dental Center. **Assistant ‘Clinical Frofessbr of- Endodontics and Chairman of Department, Harvard School of Dental Medicine; Head, Department of Endodontics, Forsyth Dental Center.
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to attempt root canal therapy in the deciduous teeth may be due to one or more of the following reasons : 1. Many endodontists may be unfamiliar with the morphology of the deciduous teeth and are therefore uncomfortable dealing with the supposedly less accessible and more tortuous roots. 2. Many endodontists have not yet learned to relate their highly sophisticated techniques for honing and shaping root canals to the morphology of deciduous teeth. 3. Some endodontists and pedodontists believe that it may take an inordinate amount of time and effort to carry out these procedures. 4. Some endodontists and pedodontists believe that since deciduous teeth are in the mouth for only 6 to 12 years, such treatment is unnecessary. 5. The deciduous teeth are in the process of either root maturation or root resorption much of the time and, therefore, must be filled with absorbable materials rather than with silver cones or gutta-percha. 6. Xany believe that it is difficult to introduce such absorbable materials to fill the root canals adequately, particularly in the apical region. 7. It is often difficult to obtain a good radiographic view of deciduous teeth because of the superimposit,ion of the succedaneous teeth, particularly in the maxillary arch. 8. It may be difficult to manage a very young child, who is frequently in pain when this type of treatment is necessary. 9. The alternative treatment of extraction and replacement by a space maintainer is easier and less expensive in the view of some clinicians. In spite of the foregoing considerations, these teeth can often be retained. In any case, infected deciduous teeth should not be allowed to remain untreated. There is no justification for allowing periapical infection to remain in the mouth of a child, any more than in the mouth of an adult. Many investigators have shown that infected deciduous teeth can affect both the succedaneous teeth and the pariapical tissues.6-12 Reported effects on the developing teeth include formation of a cyst which may envelop the permanent tooth bud, interruption of amelogenesis, enamel hypoplasia, discoloration, changed eruption sequence, ectopic eruption, axial rotation, retarded root development, loss of the permanent tooth bud by exfoliation through a chronic fistula, and loss of space. Reported effects on the periapical tissues include abscess formation, cyst formation, and osteomyelitis. Infected deciduous teeth should not be retained as such but must be either endodontically treated or extracted. Root canal therapy has been carried out successfully for the child patient.13-I7 Accordingly, the significance of the previously listed considerations should be evaluated. It is a common impression that the root canal system of deciduous teeth is more complex than that of permanent teeth. However, Hess and ZurcheP have shown that both are highly complex, having numerous lateral canals, accessory canals, anastomoses between the canals, and ramifications in the apical portion. Although Hibbard and Ireland I9 have shown that in the deciduous dentition there is an increase in the incidence of lateral and accessory canals with the
946
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Pigs. 1 and 3. Perforations on the convcs aor1 concave :qx 11 ct..q of :I rooi- of a deciduous molar caused by injudicious use of root canal istruments.
onset of root resorption, the deciduous root canal system is no more complex than that of the permanent dentition. In spite of the complexity of the root canal system in the adult dentition, root canal procedures are sucessfully accomplished. Accordingly, the complexity of the root canal system in deciduous teeth should not be considered a contraindication for complete endodontic therapy. Reported success rates for endodontic treatment of deciduous teeth vary from 41 per cent to almost 100 per cent. I1250.Z1 L4 review of these reports shows that there is a direct relationship between extent of instrumentat,ion and success. Consequently, it would seem that, as in the case of permanent teeth, thorough d&bridement and adequate instrumentation of the root canal system are essential. The dentin of the deciduous tooth appears to offer less resistance to biomechanical instrumentation, thus facilitating the honing and shaping of the root canal space. On the other hand, the roots of deciduous molars are generally more curved than those of permanent molars. Also, access to the orifices of the mesial canals of deciduous molars often has to be accomplished from a more distal direction. This problem may be overcome by extending the access cavity further mesially and buccally. Furthermore, as in the case of curved canals in permanent teeth, these canals must be instrumented judiciously and adequately with each individual instrument so as to avoid perforations. Figs. 1 and 2 illustrate inaccurate instrumentation leading to such perforations on the convex and concave aspects of the roots, respectively. It should be recognized that the objective of biomechanical instrumentation of deciduous teeth is primarily to dbbride the canals. In the permanent dentition, different shapes of the root canal system
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Fig. J. Instrument
Pulpal pathosis in deciduous and permanent teeth 947
properly
curved to facilitate
d6bridement
of canal without
perforating
root.
are required, depending on whether silver cones or gutta-percha is used and on whether lateral or vertical condensation is utilized. However, far less instrumentation is required in the deciduous dentition because less extensive shaping is necessary when filling is to be accomplished with sealers alone. In view of the need for less instrumentation, the danger of perforation is diminished. It should be further emphasized that the canals of deciduous teeth should always be d6brided with curved instruments, as shown in Fig. 3. After a reasonable amount of experience in treating deciduous teeth, the time required is generally no more, a.nd could even be less, than that required for permanent teeth. The importance of retaining deciduous teeth for their full functional period is well recognized. This is particularly true in the case of the second deciduous molar, which prevents mesial drifting of the first permanent molar. It is now generally accepted that deciduous teeth should be saved by the early removal of caries and subsequent restoration. If the pulps degenerate completely, deciduous teeth should be retained by root canal therapy. The use of the endodontic pressure syringe to introduce absorbable filling materials to the apices of deciduous root canals has been a recent innovation which has helped to solve many of the problems associated with filling these
94% Berk awl Krakow
Oral surg. Ikcemher. 1972
canals.22’ 23 The technique for use of’ the pressure syringe is not cliffic~ult ant1 is already being taught in several dental schools. The deciduous teeth shoultl hr filled with a material that would bc absorbetl as the roots are ph~siologirally resorbed. Solid-core materials, such as gutta-percha or sill-rr COIWS,shoultl not be used in deciduous teeth, since they arc not absorbable and could thercforr interfere with the eruption of the succedancous teeth. The pressure syringe affords the unique opportunity of tlepositing thick mixes of absorbable materials at the apical portion to ensure an apical seal. The root canal filling materials for deciduous teeth advocated in the literature include paste preparations that will be absorbed as the deciduous roots resorb. Two types are commonl,v used: bland zinc oxide and eugcnol preparatiom? and mummifying preparations that contain fixatives, such as paraformaldehyde.24 The former type is preferable. One of the objections to the use of mummifying pastes is the potential harmful effect of such a material if it is extruded beyond the apex, Materials deposited in the root canals of deciduous teeth are certain to become extraradicular as the roots undergo physiologic resorption. Concerning the technical problems of obtaining good radiographs in the mixed dentition, one can overcome these to some extent by the use of film holders with a paralleling technique. This method will produce roentgenograms that are accurate enough in most instances to determine the working length of the root canals of deciduous teeth. Perhaps the major reason that many endodontists do not attempt root canal therapy in children is that the,v feel uncomfortable and perhaps inadequately trained in handling an uncooperative pediatric patient. Obviously, there is no substitute for experience in allaying the pat&t’s apprehension. Even with extensive experience in handling young children in need of root, canal therapy, it may sometimes bc necessary to resort to sedation and premeditation, but in most instances it is possible to control the child adequately. With regard to the point of view that the fabrication of a space maintainer is an easier and less expensive alternative treatment, one should not overlook the many problems associated with this approach. Space maintainers are frequently lost or broken. The fixed type often requires recementation. Furthcrmore, the fabrication and insertion of a space maintainer can be quite difficult. When a deciduous second molar is extracted prior to eruption of the permanent first molar in a 3- or I-year-old child, placing a space maintainer (with a distal shoe inserted in the tissue to guide the eruption of the permanent first molar) is just as difficult as endodontic therapy would have been. Unlike permanent teeth, very little research has been carried out in endodontic treatment of the deciduous dentition. Further research is needed to explore the problems in order to establish sound biologic principles for complete root canal treatment of infected deciduous teeth. In view of the problems associated with complete root canal therapy, pedodontists have resorted to vital pulp therapy as an alternative approach whenever possible. Vital pulp therapy consists of indirect pulp capping, direct pulp capping, pulpal curettage, and pulpotomy. Its objective is to keep the remain-
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ing pulpal tissue vital. In addition, it is concerned with the prevention of deleterious effects to the pulp caused by caries, erosion, abrasion, and restorative procedures and materials. Vital pulp therapy procedures are commonly employed in the deciduous and young permanent teeth with high success rates. In spite of this, very few endodontists advocate vital pulp therapy procedures in the adult dentition. Most endodontists consider a vital exposure to be an indication for complete pulp extirpation. The reluctance to attempt vital pulp therapy procedures in the adult dentition may be due to one or more of the following : 1. Many endodontists contend that when pulp capping and pulpotomy procedures fail, the result is pulpal necrosis, and the success rate for endodontic treatment of teeth with necrotic pulps is lower than the success rate for treatment of teeth with vital p~lps.~~ 2. Many endodontists believe that vital pulp therapy procedures often cause calcification of the canals, which makes endodontic treatment more complicated if it becomes necessary.26>27 3. It has also been suggested that internal resorption could result.28* 2g 4. Langeland30 has pointed out that the new dentin bridges formed may contain dead tracts leading to the underlying tissue. 5. Some endodontists believe that the adult dental pulp does not have the recuperative powers required to heal subsequent to vital pulp therapy procedures. Since vital pulp therapy procedures have been demonstrated clinically and histologically to be successful even in patients 60 years of age and over,31l 32 and since they are certainly simpler, more readily accomplished, and consequently less expensive to the patient than are complete endodontic procedures, a critical review and re-evaluation of the entire rationale is indicated. The first question to consider is the relative success rates of vital pulp therapy and endodontic procedures. In spite of all the interest in and extensive work done to determine the success rates of vital pulp therapy and endodontic procedures, no standardization of the criteria for success has yet evolved in either category. Accordingly, it becomes difficult to make meaningful comparisons between many of these studies. In 1950, Berk33 reported on the use of calcium hydroxide in aqueous methyl cellulose. He found that in 120 cases of pulp capping and pulpotomy observed for one year, all pulpotomies were successful, and pulp capping was successful in all but three cases. In 1963, Berk31 substantiated the results for pulp capping reporting success in 94 per cent of 300 cases observed for 3 to 10 years. On the other hand, Via34 reported only a 31 per cent success rate for pulpotomy utilizing calcium hydroxide following pulpal amputation. Reported success rates therefore range from approximately 30 per cent to almost 100 per cent. A detailed comparison of the work of these two investigators shows a number of variables. For example, Vias4 injected a local anesthetic agent directly into the pulp, a procedure which can cause the contaminants in the coronal pulp tissue to be forced into the radicular pulp. Furthermore, he used a rotating bur to amputate the pulp. This procedure could force contaminants into under-
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Oral Surg. December, 1972
lying pulpal tissue and could twist and agitate the remaining pulp tissue. Epinephrine or phenylephrine was utilized to control hemorrhage, calcium hydroxide in powdered form was used as the pulp-capping agent, a.nd the pulp chamber was swabbed with a cotton pellet that had a trace of phenol on its surface. By comparison, Berk and Krakow3j utilized a technique which was designed to avoid contamination and injury to the pulp. Injections were never made directly into the pulp. Amputation was accomplished with a sharp curette making a clean incision at the orifices of the root canals, thus permitting the removal of the coronal pulp tissue without contaminating the underlying radicular pulp. This technique reduces trauma to the underlying tissue and creates an cnvironment that is more conducive to healing. Prior to amputation, all dentin chips and fragments were carefully removed and the cavity preparation was washed clean. Kalnins and Frisbie3G have shown that the forcing of sterile dentin fragments into the pulp of a caries-free tooth results in failure to heal. The mere presence of dentin dust or fragments produced inflammation with an accumulation of lymphocytes and plasma cells. They further observed that any reparative dentin formed wit.h the application of calcium hydroxide after pulpal contamination with dentin dust was defcctire. Berk and Krakow3j never used hemostatic agents to control bleeding ; nor did they use escharotic drugs, such as phenol, against the remaining pulpal tissue, since it can destroy the tissue which is expected to form new dentin. Furthermore, they used aqueous methyl cellulose as the vehicle for the calcium hydroxide, which aids in overcoming the difficulties in its handling. MassleP has suggested that methyl cellulose acts as a buffer between the pulpal tissue and the calcium hydroxide. The resultant milder irritation is more conducive to pulpal healing. When these reports are scrutinized, one can find ample explanation for the divergence in success rates. With proper case selection and appropriate technique and agents, a high percentage of success with vital pulp therapy procedures is predictable, as shown in studies by Browna and Strange,3g who found success rates of about 90 per cent after up to 4 years of observation. Concerning the success rate of endodontic procedures, there is similar diversity in the reported rate of success, varying from approximately 76 per cent to 95 per cent. a7940,41 An evaluation of these reports substantia,tes the view that proper case selection and appropriate t,echnique result in a higher percentage of success. Thus, it is apparent that vital pulp therapy and complete cndodontic procedures enjoy comparably high success rates.““> 42,43 Consequently, only a very low percentage of pulpal necrosis would occur because of failure of vital pulp therapy procedures. Therefore, the fear of pulpal necrosis subsequent to vital pulp therapy does not constitute a valid contraindication for this treatment approach. Considering the large percentage of cases in which the need for complete endodontic treatment would be obviated, the difference between the success rate for endodontic procedures in vital cases (92 per cent) 27 and in necrotic cases (76 per cent) 2r becomes insignificant. The following observations may be made regarding the impression that pulpcapping and pulpotomy procedures cause the canals to calcify subsequently, making it difficult or impossible to negotiate these canals if root canal therapy
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becomes necessary. All too frequently pulp capping or pulpotomy is attempted in teeth in which the canals are already calcified when, actually, such previously existing calcifications should be considered contraindications. When such cases fail and are referred to the endodontist for treatment, he naturally but erroneously often attributes the calcification to the use of calcium hydroxide. It should be noted that a high percentage of teeth in older patients seen by general practitioners every day have canals extremely calcified without any history of exposure to calcium hydroxide as a cavity liner or pulp-capping agent. Further, calcification of canals is often seen associated with trauma. On the other hand, it must be recognized that calcium hydroxide can cause calcification wherever it makes contact with pulpal tissue, as shown by Stanley.44 He has demonstrated with histologic sections that these calcifications do occur deep in the canals when the calcium hydroxide has been forced into the stroma of the pulp. It should be concluded from Stanley’s work with calcium hydroxide44 and from the work done by Kalnins and Frisbie36 with dentin fragments that the clinical techniques for pulp capping and pulpotomy must be such as to avoid forcing the calcium hydroxide or dentin fragments into the stroma of the pulp, where they cause these undesirable reactions. Such techniques have been described.35r 45 It has been reported in the literature several times that the use of calcium hydroxide results in internal resorptions in root canals, with the implication that such resorptions result in failure. The question, then, is how often is the resorption so extensive as to result in tooth loss. It would appear that, in view of the large number of teeth that are pulp capped daily in general dental practice, the incidence of such extensive resorption is negligible. In regard to lesser amounts of internal resorption which does not result in tooth loss, Seltzer and BenderZ7 have shown that some internal resorptions are frequently seen in histologic sections of supposedly normal teeth. Internal resorptions have also been noted as a result of trauma and treatment with agents other than calcium hydroxide, such as paraformaldehyde and zinc oxide and eugeno1.46’ 47 It has been reported that when a new dentin bridge is formed it contains dead tracts and is not always completely calcified .30This can be seen histologically, but one may question the clinical significance. There are dead tracts in all dentin, and all dentin is permeable. The fact that dead tracts and porosity have been seen histologically in these dentin bridges is not a contraindication for the direct pulp-capping or pulpotomy procedures. If a restoration must be replaced in a tooth with a new dentin bridge, the new dentin should be treated the same as any other freshly cut dentin. A liner and a base should be used to protect the underlying pulp and to provide an adequate seal prior to placement of the restoration, just as in any other tooth. Furthermore, one may raise the question of the necessity of obtaining a new dentin bridge to rehouse the pulp in a completely closed chamber. It should be sufficient for the pulp to remain vital. There are those who maintain that the adult dental pulp does not have recuperative powers. Berk and Stanley 32 have postulated that the adult pulp will eventually heal; it just takes a little longer. The amount of tissue with an adequate blood supply available to aid in the healing process is more important than the age of the patient. Because of the reduced width and/or depth of the
pulp in the adult tooth, the location of the exposure must be considered. Pulpotomy is often more successful bhan pulp capping, particularly in the area of a pulpal horn and in anterior teeth where the coronal pulp tissue is thin and ribbonlike. In these areas, the new dentin bridge formation can interrupt the circulation to the tissue lying incisal or occlusal to the newly healed area and cause necrosis.48 Class III and Class V lesions in anterior teeth and lesions involving pulpal horns in posterior teeth are of particular clinical concern. It is therefore recommended that pulpal amputation should be the treatment of choice in such cases. Costly and time-consuming root canal therapy should be avoided whenever a simpler reasonable alternative exists. Accordingly, rather than condemn vital pulp therapy procedures, it behooves the dentist to recognize and to take advantage of the biologic healing potential of the dental pulp. One should strive to create an environment that will allow the pulp to remain vital and, if the coronal pulp is already pathologically involved, to create an environment that will maintain the vitality of the radicular pulp. Recent work has shown that success can be enhanced when various age&+, such as methyl cellulose, mctacresol acetate, camphorated monochlorophenol, and, most recently, vancomycin hydrochloride are added to calcium hydroxide. 31.4g-51Vital pulp therapy utilizing accurate diagnosis, appropriate case selection, and proper technique should be put into everyday use as the situation demands. Many dentists who do not look favorably upon direct pulp capping and pulpotomy do approve of indirect pulp capping as a means of avoiding the need for root canal therapy. The pros and cons of indirect pulp capping have been discussed since 1859, when TomeP suggested that it would be better to allow a layer of discolored dentin to remain rather than to risk the loss of a tooth. There has been considerable interest in the bacterial invasion of dentinal tubules during the carious process and the consequent pulpal response. The presence of microorganisms in carious dentin depends on whet,her the process is active or arrested and on the depth of the lesion. The rate at which the carious process proceeds is also a factor. It is generally accepted that, in active lesions, the surface layers are always infected. Further, in arrested lesions, the surface layers a,re not always infected, whereas the deeper sclerotic layers are usually free of organisms.“3-Z6 Accordingly, the rationale for indirect pulp capping is that few bacteria remain in the deeper dentin layers and that, even if they find their way into the pulp, they would be inactivated. Yet, when one is confronted with the problem clinically, there is still no definitive way of determining whether one is dealing with an infected carious lesion or has reached a bacteria-free demineralized (or incompletely mineralized) zone. Disclosing dyes which are being developed have not as yet proved effective for making this distinction.57 The decision, therefore, must still be made by the clinician, who should be guided by the quality of the dentin, the depth of the lesion, and the clinical symptoms and radiographic appearance. When dentin is soft and mushy so as to offer only minimal resistance to a sharp excavator, it should always be removed. When caries extends into that portion of the tooth originally occupied by the pulp
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chamber and can be excavated to uncover harder dentin which offers reasonable resistance to a sharp excavator, indirect pulp capping can be employed. This indicates that the pulp has responded physiologically to the carious process by forming reparative dentin. When time is not a factor, it may be desirable to place the final restoration at the same visit.35 Stanley and associates 58have questioned the value of delayed filling of teeth. They stated that the formation of reparative dentin is a slow healing response of the dental pulp to trauma and seldom begins in less than 30 days, with a subsequent average daily deposition of 1.5 microns. Therefore, after 3 months a layer of at most 100 microns or 0.1 mm. can be expected. Accordingly, they have recommended the application of cavity liners and sealers for pulp protection with the immediate insertion of the final restoration. On the other hand, Nygaard-0stby 5g has advocated the two-visit procedure. He further advocated the complete removal of carious dentin before permanent restoration of the tooth. The two-visit indirect pulp-capping procedure is indicated in cases of rampant caries, where it is desirable to remove as much carious material in as many teeth as possible at a single visit, in order to get the carious process under control. In these cases, where so many carious teeth are involved, time does become a factor and temporary cement fillings can be used to facilitate treatment. The temporary cement must be removed at a later date, at which time it is possible to inspect the dentin to determine whether the remaining dentin has hardened. MjSr and his associatesGo,61have shown that when calcium hydroxide is placed against dentin, it stimulates the formation of peritubular dentin, which has been shown to increase the density of the dentin by as much as 25 per cent in 15 days. The increased dentin mineralization manifests itself as an increased radiopacity on the roentgenogram and is further evidenced of a favorable pulpal response. The following conditions should be considered contraindications to pulp capping, both direct and indirect : (1) sustained pain on the application of heat or cold, (2) a throbbing toothache, (3) a marked sensitivity to percussion, (4) tenderness to vestibular palpation, (5) periapical radiographic changes related to the pulp, (6) extensive constriction of the pulp chamber or root canals, and (7) the resorption of more than two thirds of the roots of deciduous teeth. If the coronal pulp is partially degenerated but the disease process is localized within the confines of the coronal pulp tissue, the prognosis for both indirect and direct pulp capping is not good, whereas the prognosis for pulpotomy may be still excellent. Therefore, in order to avoid complete root canal therapy, which becomes necessary when indirect pulp capping fails, pulpotomy may be the treatment of choice. On the basis of this review, one can see that there is a place both for complete endodontic procedures in deciduous teeth and for vital pulp therapy procedures in permanent teeth. The advantages to be gained are the preservation of deciduous teeth which otherwise would be extracted and the obviation of the need for more complicated endodontic procedures in the adult dentition. The realization of these gains depends upon proper case selection and techniques predicated upon sound biologic principles.
Oral Surg. L&ember,
1972
REFERENCES
1. Cohen, M. M.: Pediatric Dentistry, od. 2, St. Louis, 1961, The C. \‘. Mosby Company, p. 276. R.: Dentistry for Children, ed. 5, New York, 1964, McGraw2. Brauer, J. C., and Lindahl, Hill Book Company, Inc., pp. 450-486. 3. Hullett. G. E.: Endodontic Treatment and Conservation of Primarv i Teeth. ~> Int. Dent. J. 18: 520; 1968. 1962, Lea & Febiger,, p. 231. Grossman, L. I.: Endodontic Practice, ed. 5, Philadelphia, t Sommer, R. F., Ostrander, F. D.. and Crowlev. M. C.: Clinical Endodontics. ed. 3. Philadelphia, 1966, W. B. Saunders company, p. 1%. Processes of Deciduous Teeth on the Buds of 6. Bauer, W. II.: Effect of Periapical Permanent Teeth, Am. J. Orthodont. Oral Surg. 32: 232-241, 1946. 7. Muhler, J. C.: The Effect of Apical Inflammation of the Primary Teeth in Dental Caries in the Permanent Teeth, J. Dent. Child. 24: 209-210, 1957. 8. Shiere, F. IL., and Frankl, S. M.: The Effect of Deciduous Tooth Infection on Permanent Teeth, Dent. Progr. 2: 59-64, 1961. 9. McCormick, J., and Filostrat, D. J.: Injury to the Teeth of Succession by Abscess of the Temporary Teeth, J. Dent. Child. 34: 501-504, 1967. 10. Binns, W. H., and Eseobar, A.: Defects in Permanent Teeth Following Pulp Exposure of Primary Teeth, J. Dent. Child. 84: 4-14, 1967. 11. Winter, G. B.: Abscess Formation in Connection With Deciduous Molar Teeth, Arch. Oral Biol. 7: 373-379, 1962. 12. Matsumiya, S.: Experimental Pathological Study on the Effect of Treatment of Infected Root Canals in the Deciduous Tooth on Growth of the Permanent Tooth Germ, lnt. Dent. J. 18: 546-559, 1968. 13. Drotesr, J. A. : Pulp Therapy in Primary Teeth, J. Dent. Child. ‘34: 507-510, 1967. 14. Rabinowitch, B. Z.: Pulp Management in Primary Teeth, ORAL SURG.6: 542-550, 671-676,
1953.
15. McElroy, D.: Endodontic Treatment of Deciduous Teeth, J. am. Dent. Assoc. 50: 319.320, 1959. Primary Teeth Which Have Exposed Pulps, J. 16. Starkey, P. E.: Methods of Preserving Dent. Child. 30: 219-228, 1963. of Deciduous Teeth, Prac. Dent. Monogr. 22: l-38, 17. Bennet, C. G.: Pulpal Management 1965. of the Root Canals of the Teeth of the 18. Hess, W., and Zurcher, E.: The Anatomy Permanent and Deciduous Dentitions, New York, 1925, William Wood & Company. of the Root of the Primary Molar Teeth, 19. Hibbard, E. D., and Ireland, R. L.: Morphology 5. Dent. Child. 24: 250-257. 1957. the Conservation of Deciduous and Early Permanent Teeth, 20. Rosenstein, S. N.: Studies’in J. Dent. Res. 16: 29-31, 1937. 21. Andrew, P.: The Treatment of Infected Pulps in Deciduous and Early Permanent Teeth: An Initial Survey of 178 Cases Over a Period of Two Years, Br. Dent. J. 98: 122-126, 1955. Technique, Dent. 22. Greenberg, M.: Filling Root Canals of Deciduous Teeth by an Injection Dig. 67: 574, 1971. 23. Krakow, A., and Berk, H.: Efficient Endodontic Procedures With the Use of the Pressure Syringe, Dent. Clin. North Am., pp. 387-399, July, 1965. 24. Hannah, D. R., and Rowe, A. H. R,.: Vital Pulpotomy of Deciduous Molars Using N, and Other Materials, Br. Dent. J. 130: 99-107, 1971. 25. Seltzer, S., Bender, I. B., and Turkenkopf, S.: Factors Affecting Successful Repair After Root Canal Therapy, J. Am. Dent. Assoc. 67: 651-662, 1963. 26. Jeffrey, J. E. L.: Histological Pulp Changes Following Therapy for Exposed Deciduous Molars, J. Dent. Res. 43: 978979, 1964. 27. Seltzer, S., and Bender, I. B.: The Dental Pulp, Philadelphia, 1965, J. B. Lippincott Company. 28. Bergh, C., and Martensson, K.: Pulp Treatment in Deciduous Teeth, Odontol. Revy 6: 135-162, 1955. 29. James, V. E:, Englander, H. R., and Massler, M.: Histologic Response of Amputated Pulps to Calcmm Compounds and Antibiotics, ORAL SURG.10: 975-986, 1957. 30. Langeland, .K., Dowden, W. E., Tronstad, L., and Langeland, L. K.: Human Pulp Changes of Iatrogemc Origin, ORAL SAG. 32: 943-980, 1971. 31. Berk! H.: Pulp Capping; Re-evaluation of Criteria Based on Clinical and Histological Findings, Int. Dent. J. 13: 577581, 1963. 32. Berk, H., and Stanley, H. R., Jr.: Pulp Healing Following Capping in Human Sound and Carious Teeth, J. Dent. Res. 37: 66, 1958. 33. Berk, H.: Effect of Calcium Hydroxide Methyl-cellulose Paste on the Dental Pulp, J. Dent. Child. 17: 65, 1950.
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34. Via, W.: Evaluation of Deciduous Molars Treated by Pulpotomy and Calcium Hydroxide, J. Am. Dent. Assoc. 50: 34-43, 1955. 35. Berk, IF., and Krakow, A. A.: Efficient Vital Pulp Therapy, Dent. Clin. North Am. pp. 373-385, July, 1965. on the Healing of the 36. Kalnins. V.. and Frisbie. H. E.: Effect of Dentin Fragments Exposed Pulp, Arch. Oral’Biol. 2: 96-103, 1960. 37. Massler, M. : Pulp Curettage; a Review, J. Dent. Child. 26: 154-156, 1954. 38. Brown, W. E., Jr.: The Vital Pulpotomy Technic for the Management of Vital Exposed PU~DSin Primary and Youne Permanent Teeth, Thesis, University of Michigan, School of Dentistry, 1947. * 39. Strange, E. M.: Is Vital Pulpotomy Worthwhile$ J. Dent. Child. 20: 38, 1953. 40. Ingle, J. I. : Endodontics, Philadelphia, 1965, Lea & Febiger, p. 54. 41. Bender. I. B.. Seltzer. 5.. and Freedland. J. B.: The Relationship of Systemic Disease to Endodontic Failures ‘and Treatment Procedures, ORAL SURG. 16: 1102:1115, 1963. 42. Jeppesen, K.: Direct Pulp Capping on Primary Teeth; a Long-Term Investigation, J. Int. Assoc. Dent. Child. 10: 19, 1971. 43. Davies, G. N.: Pulp Therapy in Primary Teeth, Aust. Dent. J. 7: 111-120, 1962. 44. Stanley, H. R.: Diseases of the Pulp In Tieeke, R. W. (editor) : Oral Pathology, New York, 1965, McGraw-Hill Book Company, pp. 117-118. 45. Berk, H.: Maintaining Vitality of Injured Permanent Anterior Teeth, J. Am. Dent. Assoc. 49: 391-401, 1954. 46. Berger. J. E.: Pulr, Tissue Reaction to Formoeresol and Zinc Oxide Eueenol. u I J. Dent. Child. 82: 13-28, 1985. 47. Magnusson, B. : Therapeutic Pulpotomy in Primary Molars ; Clinical and Histological Follow-up, Odontol. Revy 22: 45-54, 1971. 48. Stanley, H. R., and Lundy, T.: Dycal Therapy for Pulp Exposures, ORAL SURG. 34: 818-827, 1972. 49. Citron, C. L., Frank], S. N., and Ruben, M.: The Histological Response of the Human Primary Dental Pulp to Metacresyl Acetate and Calcium Hydroxide Methyl Cellulose. (In press.) 50. Kozlov, M., and Massler, M.: Histologic Effects of Various Drugs on Amputated Pulps of Rat Molars, ORAL SURG.13: 455-469, 1960. 51. Gardner, D. E., Mitchell, D. F., and McDonald, R. E.: Treatment of Pulps of Monkeys With Vancomyein and Calcium Hydroxide, J. Dent. Res. 50: 1273-1277, 1971. 52. Tomes, Sir John: A System of Dental Surgery, 1859, p. 336. A., Stephan, R.M., and Muntz, J.A.: In Vitro Studies of Carious Dentin. II. 53. Dorfman, Extent of Infection in Carious Lesions, J. Am. Dent. Assoc. 36: 1901-1904, 1943. 54. Parikh, 5. R., Massler, M., and Bahn, A.: Microorganisms in Active and Arrested Carious Lesions of Dentin, N. Y. State Dent. J. 29: 347-355,1963. Shovelton, D.S.: A Study of Deep Carious Dentin, Int. Dent. J. 18: 392-405, 1968. E: Langeland, K., and Langeland, L. I(.: Indirect Capping and the Treatment of Deep Various Lesions, Int. Dent J. 18: 326-386, 1968. KrGnchke, A. : Treatment of Deep Ganous Lesions, Int. Dent. 5. 20: 338-343, 1970. E: Stanley, H. R., White, C. L., and McCray, L.: The Rate of Tertiary (Reparative) Dentin Formation in the Human Tooth. ORAL SURG.21: 180-189. 1966. 59. Nygaard-Bstby, B. : Caries Profumla and “Indirect Pulp Capping” (Guest Editorial),
ORAL SURG.33: 788-790,1972.
60. Mjar, I. A., Finn, 8. B., and Quigley, M. B.: The Effect of Calcium Hydroxide and Amalgam on Non-carious Vital Dentin, Arch. Oral Biol. 3: 283-291, 1961. 61. Finn, S. B.: Clinical Pedodontics, ed. 2, Philadelphia, 1962. W. B. Saunders Company, pp. 182-210. Reprint
requests
to:
Dr. Harold Berk Forsyth Dental Center 140 Fenway Boston, Mass. 02115
DENTAL
HARVARD
CENTER,
SCHOOL
TUFTS
OF DENTAL
UNIVERSITY
SCHOOL
OF DENTAL
MEDICINE,
MEDICINE
Endodontic treatment in the adult dentition, as practiced by most endodontists, does whereas endodontic treatment in the not include vital pulp therapy procedures, deciduous teeth, as practiced by most pedodontists, is mostly limited to vital pulp therapy procedures and rarely includes complete root canal therapy. There are many advantages to maintaining pulpless deciduous teeth, and suggestions are presented to assist the clinician in solving the problems of instrumenting and filling these canals. Vital pulp therapy procedures can also enjoy a high success rate in the adult dentition. By combining accurate diagnosis with proper ease selection and treatment techniques, successful vital pulp therapy procedures are predictable. Accordingly, complete root canal therapy can often be avoided in the adult dentition.
I
n reviewing the literature, it becomes apparent that complete endodontic treatment procedures are not usually applied to infected deciduous teeth.1-5 Conversely, vital pulp therapy procedures frequently utilized by the pedodontist are rarely applied to adult permanent teeth by the endodontist. The purpose of this article is to probe the reasons for this and to suggest that, under certain circumstances, there is a role for complete endodontic procedures in the deciduous dentition and, furthermore, that there is also a place for vital pulp therapy in the adult dentition. Regarding complete endodontic procedures in deciduous teeth, although endodontists and pedodontists agree that it is desirable to have the ability to retain these infected deciduous teeth in order to maintain space and function, both have neglected this particular phase of endodontic practice. This reluctance
*Assistant Clinical Professor, Department of Oral Pediatrics, Tufts University School of Dental Medicine; Staff Associate, Forsyth Dental Center. **Assistant ‘Clinical Frofessbr of- Endodontics and Chairman of Department, Harvard School of Dental Medicine; Head, Department of Endodontics, Forsyth Dental Center.
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to attempt root canal therapy in the deciduous teeth may be due to one or more of the following reasons : 1. Many endodontists may be unfamiliar with the morphology of the deciduous teeth and are therefore uncomfortable dealing with the supposedly less accessible and more tortuous roots. 2. Many endodontists have not yet learned to relate their highly sophisticated techniques for honing and shaping root canals to the morphology of deciduous teeth. 3. Some endodontists and pedodontists believe that it may take an inordinate amount of time and effort to carry out these procedures. 4. Some endodontists and pedodontists believe that since deciduous teeth are in the mouth for only 6 to 12 years, such treatment is unnecessary. 5. The deciduous teeth are in the process of either root maturation or root resorption much of the time and, therefore, must be filled with absorbable materials rather than with silver cones or gutta-percha. 6. Xany believe that it is difficult to introduce such absorbable materials to fill the root canals adequately, particularly in the apical region. 7. It is often difficult to obtain a good radiographic view of deciduous teeth because of the superimposit,ion of the succedaneous teeth, particularly in the maxillary arch. 8. It may be difficult to manage a very young child, who is frequently in pain when this type of treatment is necessary. 9. The alternative treatment of extraction and replacement by a space maintainer is easier and less expensive in the view of some clinicians. In spite of the foregoing considerations, these teeth can often be retained. In any case, infected deciduous teeth should not be allowed to remain untreated. There is no justification for allowing periapical infection to remain in the mouth of a child, any more than in the mouth of an adult. Many investigators have shown that infected deciduous teeth can affect both the succedaneous teeth and the pariapical tissues.6-12 Reported effects on the developing teeth include formation of a cyst which may envelop the permanent tooth bud, interruption of amelogenesis, enamel hypoplasia, discoloration, changed eruption sequence, ectopic eruption, axial rotation, retarded root development, loss of the permanent tooth bud by exfoliation through a chronic fistula, and loss of space. Reported effects on the periapical tissues include abscess formation, cyst formation, and osteomyelitis. Infected deciduous teeth should not be retained as such but must be either endodontically treated or extracted. Root canal therapy has been carried out successfully for the child patient.13-I7 Accordingly, the significance of the previously listed considerations should be evaluated. It is a common impression that the root canal system of deciduous teeth is more complex than that of permanent teeth. However, Hess and ZurcheP have shown that both are highly complex, having numerous lateral canals, accessory canals, anastomoses between the canals, and ramifications in the apical portion. Although Hibbard and Ireland I9 have shown that in the deciduous dentition there is an increase in the incidence of lateral and accessory canals with the
946
Berk and Krtrkow
Pigs. 1 and 3. Perforations on the convcs aor1 concave :qx 11 ct..q of :I rooi- of a deciduous molar caused by injudicious use of root canal istruments.
onset of root resorption, the deciduous root canal system is no more complex than that of the permanent dentition. In spite of the complexity of the root canal system in the adult dentition, root canal procedures are sucessfully accomplished. Accordingly, the complexity of the root canal system in deciduous teeth should not be considered a contraindication for complete endodontic therapy. Reported success rates for endodontic treatment of deciduous teeth vary from 41 per cent to almost 100 per cent. I1250.Z1 L4 review of these reports shows that there is a direct relationship between extent of instrumentat,ion and success. Consequently, it would seem that, as in the case of permanent teeth, thorough d&bridement and adequate instrumentation of the root canal system are essential. The dentin of the deciduous tooth appears to offer less resistance to biomechanical instrumentation, thus facilitating the honing and shaping of the root canal space. On the other hand, the roots of deciduous molars are generally more curved than those of permanent molars. Also, access to the orifices of the mesial canals of deciduous molars often has to be accomplished from a more distal direction. This problem may be overcome by extending the access cavity further mesially and buccally. Furthermore, as in the case of curved canals in permanent teeth, these canals must be instrumented judiciously and adequately with each individual instrument so as to avoid perforations. Figs. 1 and 2 illustrate inaccurate instrumentation leading to such perforations on the convex and concave aspects of the roots, respectively. It should be recognized that the objective of biomechanical instrumentation of deciduous teeth is primarily to dbbride the canals. In the permanent dentition, different shapes of the root canal system
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Fig. J. Instrument
Pulpal pathosis in deciduous and permanent teeth 947
properly
curved to facilitate
d6bridement
of canal without
perforating
root.
are required, depending on whether silver cones or gutta-percha is used and on whether lateral or vertical condensation is utilized. However, far less instrumentation is required in the deciduous dentition because less extensive shaping is necessary when filling is to be accomplished with sealers alone. In view of the need for less instrumentation, the danger of perforation is diminished. It should be further emphasized that the canals of deciduous teeth should always be d6brided with curved instruments, as shown in Fig. 3. After a reasonable amount of experience in treating deciduous teeth, the time required is generally no more, a.nd could even be less, than that required for permanent teeth. The importance of retaining deciduous teeth for their full functional period is well recognized. This is particularly true in the case of the second deciduous molar, which prevents mesial drifting of the first permanent molar. It is now generally accepted that deciduous teeth should be saved by the early removal of caries and subsequent restoration. If the pulps degenerate completely, deciduous teeth should be retained by root canal therapy. The use of the endodontic pressure syringe to introduce absorbable filling materials to the apices of deciduous root canals has been a recent innovation which has helped to solve many of the problems associated with filling these
94% Berk awl Krakow
Oral surg. Ikcemher. 1972
canals.22’ 23 The technique for use of’ the pressure syringe is not cliffic~ult ant1 is already being taught in several dental schools. The deciduous teeth shoultl hr filled with a material that would bc absorbetl as the roots are ph~siologirally resorbed. Solid-core materials, such as gutta-percha or sill-rr COIWS,shoultl not be used in deciduous teeth, since they arc not absorbable and could thercforr interfere with the eruption of the succedancous teeth. The pressure syringe affords the unique opportunity of tlepositing thick mixes of absorbable materials at the apical portion to ensure an apical seal. The root canal filling materials for deciduous teeth advocated in the literature include paste preparations that will be absorbed as the deciduous roots resorb. Two types are commonl,v used: bland zinc oxide and eugcnol preparatiom? and mummifying preparations that contain fixatives, such as paraformaldehyde.24 The former type is preferable. One of the objections to the use of mummifying pastes is the potential harmful effect of such a material if it is extruded beyond the apex, Materials deposited in the root canals of deciduous teeth are certain to become extraradicular as the roots undergo physiologic resorption. Concerning the technical problems of obtaining good radiographs in the mixed dentition, one can overcome these to some extent by the use of film holders with a paralleling technique. This method will produce roentgenograms that are accurate enough in most instances to determine the working length of the root canals of deciduous teeth. Perhaps the major reason that many endodontists do not attempt root canal therapy in children is that the,v feel uncomfortable and perhaps inadequately trained in handling an uncooperative pediatric patient. Obviously, there is no substitute for experience in allaying the pat&t’s apprehension. Even with extensive experience in handling young children in need of root, canal therapy, it may sometimes bc necessary to resort to sedation and premeditation, but in most instances it is possible to control the child adequately. With regard to the point of view that the fabrication of a space maintainer is an easier and less expensive alternative treatment, one should not overlook the many problems associated with this approach. Space maintainers are frequently lost or broken. The fixed type often requires recementation. Furthcrmore, the fabrication and insertion of a space maintainer can be quite difficult. When a deciduous second molar is extracted prior to eruption of the permanent first molar in a 3- or I-year-old child, placing a space maintainer (with a distal shoe inserted in the tissue to guide the eruption of the permanent first molar) is just as difficult as endodontic therapy would have been. Unlike permanent teeth, very little research has been carried out in endodontic treatment of the deciduous dentition. Further research is needed to explore the problems in order to establish sound biologic principles for complete root canal treatment of infected deciduous teeth. In view of the problems associated with complete root canal therapy, pedodontists have resorted to vital pulp therapy as an alternative approach whenever possible. Vital pulp therapy consists of indirect pulp capping, direct pulp capping, pulpal curettage, and pulpotomy. Its objective is to keep the remain-
Pulpal
pathosis in deciduous and permanent
teeth
949
ing pulpal tissue vital. In addition, it is concerned with the prevention of deleterious effects to the pulp caused by caries, erosion, abrasion, and restorative procedures and materials. Vital pulp therapy procedures are commonly employed in the deciduous and young permanent teeth with high success rates. In spite of this, very few endodontists advocate vital pulp therapy procedures in the adult dentition. Most endodontists consider a vital exposure to be an indication for complete pulp extirpation. The reluctance to attempt vital pulp therapy procedures in the adult dentition may be due to one or more of the following : 1. Many endodontists contend that when pulp capping and pulpotomy procedures fail, the result is pulpal necrosis, and the success rate for endodontic treatment of teeth with necrotic pulps is lower than the success rate for treatment of teeth with vital p~lps.~~ 2. Many endodontists believe that vital pulp therapy procedures often cause calcification of the canals, which makes endodontic treatment more complicated if it becomes necessary.26>27 3. It has also been suggested that internal resorption could result.28* 2g 4. Langeland30 has pointed out that the new dentin bridges formed may contain dead tracts leading to the underlying tissue. 5. Some endodontists believe that the adult dental pulp does not have the recuperative powers required to heal subsequent to vital pulp therapy procedures. Since vital pulp therapy procedures have been demonstrated clinically and histologically to be successful even in patients 60 years of age and over,31l 32 and since they are certainly simpler, more readily accomplished, and consequently less expensive to the patient than are complete endodontic procedures, a critical review and re-evaluation of the entire rationale is indicated. The first question to consider is the relative success rates of vital pulp therapy and endodontic procedures. In spite of all the interest in and extensive work done to determine the success rates of vital pulp therapy and endodontic procedures, no standardization of the criteria for success has yet evolved in either category. Accordingly, it becomes difficult to make meaningful comparisons between many of these studies. In 1950, Berk33 reported on the use of calcium hydroxide in aqueous methyl cellulose. He found that in 120 cases of pulp capping and pulpotomy observed for one year, all pulpotomies were successful, and pulp capping was successful in all but three cases. In 1963, Berk31 substantiated the results for pulp capping reporting success in 94 per cent of 300 cases observed for 3 to 10 years. On the other hand, Via34 reported only a 31 per cent success rate for pulpotomy utilizing calcium hydroxide following pulpal amputation. Reported success rates therefore range from approximately 30 per cent to almost 100 per cent. A detailed comparison of the work of these two investigators shows a number of variables. For example, Vias4 injected a local anesthetic agent directly into the pulp, a procedure which can cause the contaminants in the coronal pulp tissue to be forced into the radicular pulp. Furthermore, he used a rotating bur to amputate the pulp. This procedure could force contaminants into under-
950
Berk and h’rakow
Oral Surg. December, 1972
lying pulpal tissue and could twist and agitate the remaining pulp tissue. Epinephrine or phenylephrine was utilized to control hemorrhage, calcium hydroxide in powdered form was used as the pulp-capping agent, a.nd the pulp chamber was swabbed with a cotton pellet that had a trace of phenol on its surface. By comparison, Berk and Krakow3j utilized a technique which was designed to avoid contamination and injury to the pulp. Injections were never made directly into the pulp. Amputation was accomplished with a sharp curette making a clean incision at the orifices of the root canals, thus permitting the removal of the coronal pulp tissue without contaminating the underlying radicular pulp. This technique reduces trauma to the underlying tissue and creates an cnvironment that is more conducive to healing. Prior to amputation, all dentin chips and fragments were carefully removed and the cavity preparation was washed clean. Kalnins and Frisbie3G have shown that the forcing of sterile dentin fragments into the pulp of a caries-free tooth results in failure to heal. The mere presence of dentin dust or fragments produced inflammation with an accumulation of lymphocytes and plasma cells. They further observed that any reparative dentin formed wit.h the application of calcium hydroxide after pulpal contamination with dentin dust was defcctire. Berk and Krakow3j never used hemostatic agents to control bleeding ; nor did they use escharotic drugs, such as phenol, against the remaining pulpal tissue, since it can destroy the tissue which is expected to form new dentin. Furthermore, they used aqueous methyl cellulose as the vehicle for the calcium hydroxide, which aids in overcoming the difficulties in its handling. MassleP has suggested that methyl cellulose acts as a buffer between the pulpal tissue and the calcium hydroxide. The resultant milder irritation is more conducive to pulpal healing. When these reports are scrutinized, one can find ample explanation for the divergence in success rates. With proper case selection and appropriate technique and agents, a high percentage of success with vital pulp therapy procedures is predictable, as shown in studies by Browna and Strange,3g who found success rates of about 90 per cent after up to 4 years of observation. Concerning the success rate of endodontic procedures, there is similar diversity in the reported rate of success, varying from approximately 76 per cent to 95 per cent. a7940,41 An evaluation of these reports substantia,tes the view that proper case selection and appropriate t,echnique result in a higher percentage of success. Thus, it is apparent that vital pulp therapy and complete cndodontic procedures enjoy comparably high success rates.““> 42,43 Consequently, only a very low percentage of pulpal necrosis would occur because of failure of vital pulp therapy procedures. Therefore, the fear of pulpal necrosis subsequent to vital pulp therapy does not constitute a valid contraindication for this treatment approach. Considering the large percentage of cases in which the need for complete endodontic treatment would be obviated, the difference between the success rate for endodontic procedures in vital cases (92 per cent) 27 and in necrotic cases (76 per cent) 2r becomes insignificant. The following observations may be made regarding the impression that pulpcapping and pulpotomy procedures cause the canals to calcify subsequently, making it difficult or impossible to negotiate these canals if root canal therapy
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Pulpal
pathosis in deciduous and permanent
teeth
951
becomes necessary. All too frequently pulp capping or pulpotomy is attempted in teeth in which the canals are already calcified when, actually, such previously existing calcifications should be considered contraindications. When such cases fail and are referred to the endodontist for treatment, he naturally but erroneously often attributes the calcification to the use of calcium hydroxide. It should be noted that a high percentage of teeth in older patients seen by general practitioners every day have canals extremely calcified without any history of exposure to calcium hydroxide as a cavity liner or pulp-capping agent. Further, calcification of canals is often seen associated with trauma. On the other hand, it must be recognized that calcium hydroxide can cause calcification wherever it makes contact with pulpal tissue, as shown by Stanley.44 He has demonstrated with histologic sections that these calcifications do occur deep in the canals when the calcium hydroxide has been forced into the stroma of the pulp. It should be concluded from Stanley’s work with calcium hydroxide44 and from the work done by Kalnins and Frisbie36 with dentin fragments that the clinical techniques for pulp capping and pulpotomy must be such as to avoid forcing the calcium hydroxide or dentin fragments into the stroma of the pulp, where they cause these undesirable reactions. Such techniques have been described.35r 45 It has been reported in the literature several times that the use of calcium hydroxide results in internal resorptions in root canals, with the implication that such resorptions result in failure. The question, then, is how often is the resorption so extensive as to result in tooth loss. It would appear that, in view of the large number of teeth that are pulp capped daily in general dental practice, the incidence of such extensive resorption is negligible. In regard to lesser amounts of internal resorption which does not result in tooth loss, Seltzer and BenderZ7 have shown that some internal resorptions are frequently seen in histologic sections of supposedly normal teeth. Internal resorptions have also been noted as a result of trauma and treatment with agents other than calcium hydroxide, such as paraformaldehyde and zinc oxide and eugeno1.46’ 47 It has been reported that when a new dentin bridge is formed it contains dead tracts and is not always completely calcified .30This can be seen histologically, but one may question the clinical significance. There are dead tracts in all dentin, and all dentin is permeable. The fact that dead tracts and porosity have been seen histologically in these dentin bridges is not a contraindication for the direct pulp-capping or pulpotomy procedures. If a restoration must be replaced in a tooth with a new dentin bridge, the new dentin should be treated the same as any other freshly cut dentin. A liner and a base should be used to protect the underlying pulp and to provide an adequate seal prior to placement of the restoration, just as in any other tooth. Furthermore, one may raise the question of the necessity of obtaining a new dentin bridge to rehouse the pulp in a completely closed chamber. It should be sufficient for the pulp to remain vital. There are those who maintain that the adult dental pulp does not have recuperative powers. Berk and Stanley 32 have postulated that the adult pulp will eventually heal; it just takes a little longer. The amount of tissue with an adequate blood supply available to aid in the healing process is more important than the age of the patient. Because of the reduced width and/or depth of the
pulp in the adult tooth, the location of the exposure must be considered. Pulpotomy is often more successful bhan pulp capping, particularly in the area of a pulpal horn and in anterior teeth where the coronal pulp tissue is thin and ribbonlike. In these areas, the new dentin bridge formation can interrupt the circulation to the tissue lying incisal or occlusal to the newly healed area and cause necrosis.48 Class III and Class V lesions in anterior teeth and lesions involving pulpal horns in posterior teeth are of particular clinical concern. It is therefore recommended that pulpal amputation should be the treatment of choice in such cases. Costly and time-consuming root canal therapy should be avoided whenever a simpler reasonable alternative exists. Accordingly, rather than condemn vital pulp therapy procedures, it behooves the dentist to recognize and to take advantage of the biologic healing potential of the dental pulp. One should strive to create an environment that will allow the pulp to remain vital and, if the coronal pulp is already pathologically involved, to create an environment that will maintain the vitality of the radicular pulp. Recent work has shown that success can be enhanced when various age&+, such as methyl cellulose, mctacresol acetate, camphorated monochlorophenol, and, most recently, vancomycin hydrochloride are added to calcium hydroxide. 31.4g-51Vital pulp therapy utilizing accurate diagnosis, appropriate case selection, and proper technique should be put into everyday use as the situation demands. Many dentists who do not look favorably upon direct pulp capping and pulpotomy do approve of indirect pulp capping as a means of avoiding the need for root canal therapy. The pros and cons of indirect pulp capping have been discussed since 1859, when TomeP suggested that it would be better to allow a layer of discolored dentin to remain rather than to risk the loss of a tooth. There has been considerable interest in the bacterial invasion of dentinal tubules during the carious process and the consequent pulpal response. The presence of microorganisms in carious dentin depends on whet,her the process is active or arrested and on the depth of the lesion. The rate at which the carious process proceeds is also a factor. It is generally accepted that, in active lesions, the surface layers are always infected. Further, in arrested lesions, the surface layers a,re not always infected, whereas the deeper sclerotic layers are usually free of organisms.“3-Z6 Accordingly, the rationale for indirect pulp capping is that few bacteria remain in the deeper dentin layers and that, even if they find their way into the pulp, they would be inactivated. Yet, when one is confronted with the problem clinically, there is still no definitive way of determining whether one is dealing with an infected carious lesion or has reached a bacteria-free demineralized (or incompletely mineralized) zone. Disclosing dyes which are being developed have not as yet proved effective for making this distinction.57 The decision, therefore, must still be made by the clinician, who should be guided by the quality of the dentin, the depth of the lesion, and the clinical symptoms and radiographic appearance. When dentin is soft and mushy so as to offer only minimal resistance to a sharp excavator, it should always be removed. When caries extends into that portion of the tooth originally occupied by the pulp
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Pulpal
pathosis in deciduous and permanent
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953
chamber and can be excavated to uncover harder dentin which offers reasonable resistance to a sharp excavator, indirect pulp capping can be employed. This indicates that the pulp has responded physiologically to the carious process by forming reparative dentin. When time is not a factor, it may be desirable to place the final restoration at the same visit.35 Stanley and associates 58have questioned the value of delayed filling of teeth. They stated that the formation of reparative dentin is a slow healing response of the dental pulp to trauma and seldom begins in less than 30 days, with a subsequent average daily deposition of 1.5 microns. Therefore, after 3 months a layer of at most 100 microns or 0.1 mm. can be expected. Accordingly, they have recommended the application of cavity liners and sealers for pulp protection with the immediate insertion of the final restoration. On the other hand, Nygaard-0stby 5g has advocated the two-visit procedure. He further advocated the complete removal of carious dentin before permanent restoration of the tooth. The two-visit indirect pulp-capping procedure is indicated in cases of rampant caries, where it is desirable to remove as much carious material in as many teeth as possible at a single visit, in order to get the carious process under control. In these cases, where so many carious teeth are involved, time does become a factor and temporary cement fillings can be used to facilitate treatment. The temporary cement must be removed at a later date, at which time it is possible to inspect the dentin to determine whether the remaining dentin has hardened. MjSr and his associatesGo,61have shown that when calcium hydroxide is placed against dentin, it stimulates the formation of peritubular dentin, which has been shown to increase the density of the dentin by as much as 25 per cent in 15 days. The increased dentin mineralization manifests itself as an increased radiopacity on the roentgenogram and is further evidenced of a favorable pulpal response. The following conditions should be considered contraindications to pulp capping, both direct and indirect : (1) sustained pain on the application of heat or cold, (2) a throbbing toothache, (3) a marked sensitivity to percussion, (4) tenderness to vestibular palpation, (5) periapical radiographic changes related to the pulp, (6) extensive constriction of the pulp chamber or root canals, and (7) the resorption of more than two thirds of the roots of deciduous teeth. If the coronal pulp is partially degenerated but the disease process is localized within the confines of the coronal pulp tissue, the prognosis for both indirect and direct pulp capping is not good, whereas the prognosis for pulpotomy may be still excellent. Therefore, in order to avoid complete root canal therapy, which becomes necessary when indirect pulp capping fails, pulpotomy may be the treatment of choice. On the basis of this review, one can see that there is a place both for complete endodontic procedures in deciduous teeth and for vital pulp therapy procedures in permanent teeth. The advantages to be gained are the preservation of deciduous teeth which otherwise would be extracted and the obviation of the need for more complicated endodontic procedures in the adult dentition. The realization of these gains depends upon proper case selection and techniques predicated upon sound biologic principles.
Oral Surg. L&ember,
1972
REFERENCES
1. Cohen, M. M.: Pediatric Dentistry, od. 2, St. Louis, 1961, The C. \‘. Mosby Company, p. 276. R.: Dentistry for Children, ed. 5, New York, 1964, McGraw2. Brauer, J. C., and Lindahl, Hill Book Company, Inc., pp. 450-486. 3. Hullett. G. E.: Endodontic Treatment and Conservation of Primarv i Teeth. ~> Int. Dent. J. 18: 520; 1968. 1962, Lea & Febiger,, p. 231. Grossman, L. I.: Endodontic Practice, ed. 5, Philadelphia, t Sommer, R. F., Ostrander, F. D.. and Crowlev. M. C.: Clinical Endodontics. ed. 3. Philadelphia, 1966, W. B. Saunders company, p. 1%. Processes of Deciduous Teeth on the Buds of 6. Bauer, W. II.: Effect of Periapical Permanent Teeth, Am. J. Orthodont. Oral Surg. 32: 232-241, 1946. 7. Muhler, J. C.: The Effect of Apical Inflammation of the Primary Teeth in Dental Caries in the Permanent Teeth, J. Dent. Child. 24: 209-210, 1957. 8. Shiere, F. IL., and Frankl, S. M.: The Effect of Deciduous Tooth Infection on Permanent Teeth, Dent. Progr. 2: 59-64, 1961. 9. McCormick, J., and Filostrat, D. J.: Injury to the Teeth of Succession by Abscess of the Temporary Teeth, J. Dent. Child. 34: 501-504, 1967. 10. Binns, W. H., and Eseobar, A.: Defects in Permanent Teeth Following Pulp Exposure of Primary Teeth, J. Dent. Child. 84: 4-14, 1967. 11. Winter, G. B.: Abscess Formation in Connection With Deciduous Molar Teeth, Arch. Oral Biol. 7: 373-379, 1962. 12. Matsumiya, S.: Experimental Pathological Study on the Effect of Treatment of Infected Root Canals in the Deciduous Tooth on Growth of the Permanent Tooth Germ, lnt. Dent. J. 18: 546-559, 1968. 13. Drotesr, J. A. : Pulp Therapy in Primary Teeth, J. Dent. Child. ‘34: 507-510, 1967. 14. Rabinowitch, B. Z.: Pulp Management in Primary Teeth, ORAL SURG.6: 542-550, 671-676,
1953.
15. McElroy, D.: Endodontic Treatment of Deciduous Teeth, J. am. Dent. Assoc. 50: 319.320, 1959. Primary Teeth Which Have Exposed Pulps, J. 16. Starkey, P. E.: Methods of Preserving Dent. Child. 30: 219-228, 1963. of Deciduous Teeth, Prac. Dent. Monogr. 22: l-38, 17. Bennet, C. G.: Pulpal Management 1965. of the Root Canals of the Teeth of the 18. Hess, W., and Zurcher, E.: The Anatomy Permanent and Deciduous Dentitions, New York, 1925, William Wood & Company. of the Root of the Primary Molar Teeth, 19. Hibbard, E. D., and Ireland, R. L.: Morphology 5. Dent. Child. 24: 250-257. 1957. the Conservation of Deciduous and Early Permanent Teeth, 20. Rosenstein, S. N.: Studies’in J. Dent. Res. 16: 29-31, 1937. 21. Andrew, P.: The Treatment of Infected Pulps in Deciduous and Early Permanent Teeth: An Initial Survey of 178 Cases Over a Period of Two Years, Br. Dent. J. 98: 122-126, 1955. Technique, Dent. 22. Greenberg, M.: Filling Root Canals of Deciduous Teeth by an Injection Dig. 67: 574, 1971. 23. Krakow, A., and Berk, H.: Efficient Endodontic Procedures With the Use of the Pressure Syringe, Dent. Clin. North Am., pp. 387-399, July, 1965. 24. Hannah, D. R., and Rowe, A. H. R,.: Vital Pulpotomy of Deciduous Molars Using N, and Other Materials, Br. Dent. J. 130: 99-107, 1971. 25. Seltzer, S., Bender, I. B., and Turkenkopf, S.: Factors Affecting Successful Repair After Root Canal Therapy, J. Am. Dent. Assoc. 67: 651-662, 1963. 26. Jeffrey, J. E. L.: Histological Pulp Changes Following Therapy for Exposed Deciduous Molars, J. Dent. Res. 43: 978979, 1964. 27. Seltzer, S., and Bender, I. B.: The Dental Pulp, Philadelphia, 1965, J. B. Lippincott Company. 28. Bergh, C., and Martensson, K.: Pulp Treatment in Deciduous Teeth, Odontol. Revy 6: 135-162, 1955. 29. James, V. E:, Englander, H. R., and Massler, M.: Histologic Response of Amputated Pulps to Calcmm Compounds and Antibiotics, ORAL SURG.10: 975-986, 1957. 30. Langeland, .K., Dowden, W. E., Tronstad, L., and Langeland, L. K.: Human Pulp Changes of Iatrogemc Origin, ORAL SAG. 32: 943-980, 1971. 31. Berk! H.: Pulp Capping; Re-evaluation of Criteria Based on Clinical and Histological Findings, Int. Dent. J. 13: 577581, 1963. 32. Berk, H., and Stanley, H. R., Jr.: Pulp Healing Following Capping in Human Sound and Carious Teeth, J. Dent. Res. 37: 66, 1958. 33. Berk, H.: Effect of Calcium Hydroxide Methyl-cellulose Paste on the Dental Pulp, J. Dent. Child. 17: 65, 1950.
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34. Via, W.: Evaluation of Deciduous Molars Treated by Pulpotomy and Calcium Hydroxide, J. Am. Dent. Assoc. 50: 34-43, 1955. 35. Berk, IF., and Krakow, A. A.: Efficient Vital Pulp Therapy, Dent. Clin. North Am. pp. 373-385, July, 1965. on the Healing of the 36. Kalnins. V.. and Frisbie. H. E.: Effect of Dentin Fragments Exposed Pulp, Arch. Oral’Biol. 2: 96-103, 1960. 37. Massler, M. : Pulp Curettage; a Review, J. Dent. Child. 26: 154-156, 1954. 38. Brown, W. E., Jr.: The Vital Pulpotomy Technic for the Management of Vital Exposed PU~DSin Primary and Youne Permanent Teeth, Thesis, University of Michigan, School of Dentistry, 1947. * 39. Strange, E. M.: Is Vital Pulpotomy Worthwhile$ J. Dent. Child. 20: 38, 1953. 40. Ingle, J. I. : Endodontics, Philadelphia, 1965, Lea & Febiger, p. 54. 41. Bender. I. B.. Seltzer. 5.. and Freedland. J. B.: The Relationship of Systemic Disease to Endodontic Failures ‘and Treatment Procedures, ORAL SURG. 16: 1102:1115, 1963. 42. Jeppesen, K.: Direct Pulp Capping on Primary Teeth; a Long-Term Investigation, J. Int. Assoc. Dent. Child. 10: 19, 1971. 43. Davies, G. N.: Pulp Therapy in Primary Teeth, Aust. Dent. J. 7: 111-120, 1962. 44. Stanley, H. R.: Diseases of the Pulp In Tieeke, R. W. (editor) : Oral Pathology, New York, 1965, McGraw-Hill Book Company, pp. 117-118. 45. Berk, H.: Maintaining Vitality of Injured Permanent Anterior Teeth, J. Am. Dent. Assoc. 49: 391-401, 1954. 46. Berger. J. E.: Pulr, Tissue Reaction to Formoeresol and Zinc Oxide Eueenol. u I J. Dent. Child. 82: 13-28, 1985. 47. Magnusson, B. : Therapeutic Pulpotomy in Primary Molars ; Clinical and Histological Follow-up, Odontol. Revy 22: 45-54, 1971. 48. Stanley, H. R., and Lundy, T.: Dycal Therapy for Pulp Exposures, ORAL SURG. 34: 818-827, 1972. 49. Citron, C. L., Frank], S. N., and Ruben, M.: The Histological Response of the Human Primary Dental Pulp to Metacresyl Acetate and Calcium Hydroxide Methyl Cellulose. (In press.) 50. Kozlov, M., and Massler, M.: Histologic Effects of Various Drugs on Amputated Pulps of Rat Molars, ORAL SURG.13: 455-469, 1960. 51. Gardner, D. E., Mitchell, D. F., and McDonald, R. E.: Treatment of Pulps of Monkeys With Vancomyein and Calcium Hydroxide, J. Dent. Res. 50: 1273-1277, 1971. 52. Tomes, Sir John: A System of Dental Surgery, 1859, p. 336. A., Stephan, R.M., and Muntz, J.A.: In Vitro Studies of Carious Dentin. II. 53. Dorfman, Extent of Infection in Carious Lesions, J. Am. Dent. Assoc. 36: 1901-1904, 1943. 54. Parikh, 5. R., Massler, M., and Bahn, A.: Microorganisms in Active and Arrested Carious Lesions of Dentin, N. Y. State Dent. J. 29: 347-355,1963. Shovelton, D.S.: A Study of Deep Carious Dentin, Int. Dent. J. 18: 392-405, 1968. E: Langeland, K., and Langeland, L. I(.: Indirect Capping and the Treatment of Deep Various Lesions, Int. Dent J. 18: 326-386, 1968. KrGnchke, A. : Treatment of Deep Ganous Lesions, Int. Dent. 5. 20: 338-343, 1970. E: Stanley, H. R., White, C. L., and McCray, L.: The Rate of Tertiary (Reparative) Dentin Formation in the Human Tooth. ORAL SURG.21: 180-189. 1966. 59. Nygaard-Bstby, B. : Caries Profumla and “Indirect Pulp Capping” (Guest Editorial),
ORAL SURG.33: 788-790,1972.
60. Mjar, I. A., Finn, 8. B., and Quigley, M. B.: The Effect of Calcium Hydroxide and Amalgam on Non-carious Vital Dentin, Arch. Oral Biol. 3: 283-291, 1961. 61. Finn, S. B.: Clinical Pedodontics, ed. 2, Philadelphia, 1962. W. B. Saunders Company, pp. 182-210. Reprint
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