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Role of preventive endodontics in maintenance of the teeth
endodontics Editor:
MILTON SISKIN, D.D.S. Collegeof Dentistry The Universityof Tennessee 847 MonroeAvenue Memphis,Tennessee 38163
Role of preventive endodontics in maintenance of the teeth Louis I. Grossman, D.D.S., Dr.med.dent., Philadelphia, SCHOOL
OF DENTAL
MEDICINE,
UNIVERSITY
Pa.
OF PENNSYLVANIA
Preventive measuresin order to prevent decay and retain a healthy pulp are described,proceduresare outlined which prevent pulp irritation and pulp exposure so as to conserve its integrity, and endodontic proceduresto preservethe tooth either by conservative or surgical means,and so prevent its loss, are presented.
T here is an old saying, “To
prevent a big tear, sew a little one.” The little tear in dentistry is incipient caries; the big one is periapical involvement which may lead to loss of the tooth. Both the little tear and the big one can be prevented. Whatever protects against caries protects the pulp and precludes the need for endodontic treatment. Today, more than ever before, it is within the ability of the general practitioner to prevent loss of teeth. A number of years ago, before treatment with fluorides becamea reality, Loeb4 of New Haven showed statistically that periodic professional care and preventive home care could reduce the incidence of decay and loss of teeth. Loeb was an earnest general practitioner whose successin preventing decay and saving teeth for his patients was due to a personal education program in caries prevention basedon what was known at that time. With an increasein knowledge and meansto prevent decay since that time, we can expect an even higher successrate in preventing decay and endodontic involvement which may lead to loss of teeth. CROWN PROTECTION:
FIRST LINE OF DEFENSE
Preventive endodontics begins with preservation of the integrity of the enamelprotection against decay and trauma. Let us consider the factors that could be used to protect the crown of the tooth. Fluoridation of the community water supply, in which the general dentist has only a passiverole, is statedto reducecaries by 60 per cent and topical application of fluorides, in which he has an active role, is expectedto reduce it by 3.5per cent. Tooth brushing with a fluoride dentifrice and daily mouth rinsing with a 0.3 per cent 448
0030-4220/78/0345-044448$00.40/O
0
1978 The C. V. Mosby Co.
Volume 45 Number3
Preventive endodontics in maintenance of teeth
449
neutral fluoride solution will help to reduce the incidence of decay appreciably. An adhesiveplastic sealantapplied by the dentist to the occlusal surfacesof teeth also offers protection against decay. Restriction of fermentable carboyhydrates and reasonableavoidance of sticky, pasty foods, which contribute to the formation of plaque, will help to prevent decay and periodontal diseaseas well. Limiting the intake of food, which meansno snacking, will also limit the number of times acids can develop on the tooth surface. Periodic prophylaxis and examination by the dentist or hygienist will do much to detect incipient decay, or decalcified “white spots” on enamel. Such areasmust be filled promptly to prevent them from becoming larger, and an effort should be madeto recalcify decalcified areas. A word should be said about trauma which may lead to endodontic treatment or even loss of a tooth. Dentists have beenremiss in advising their young patients who participate in sports, and adults who work in industry, what to do to prevent fracture of the crown or root, or avulsion, of an anterior tooth. All too few young people wear some means of protection to the mouth during sport activities, such as a simple intermaxillary mouth guard. In addition, those with an overjet or an open bite are particularly subject to traumatic injury becauseof lack of adequatecoverage of the teeth by the lips. Men and women working with tools in industry are also subjectto accidentalinjury of the teeth and should be advised how to prevent such accidents. Furthermore, the general public is innocently ignorant of what to do if a tooth is avulsed becauseof the lack of an advisory educational campaign by the dental profession. Many avulsed teeth would serve out their natural life-span if only the patient knew what to do, and what not to do, when a tooth is avulsed. The best treatment, in essence,is to wash the tooth and immediately replace it in its socket, to be treated later by the dentist; the next best procedure is to hold it in the vestibule of the mouth and then have it replanted by the dentist; another satisfactory method is to place the tooth in a cup of water and have it replanted by the dentist; and the worst procedure is to wrap it in a handkerchief, tissue paper, or cotton, as this dries out and kills the cells of the periodontal ligament so that the tooth later becomesankylosed and mobile. PULP PROTECTION (NO EXPOSURE): SECOND LINE OF DEFENSE
The secondline of defenseis pulp protection. When the enamelhasbeenpenetratedby caries we must think in terms of protecting the pulp. This involves a number of do’s and dont’s. One needsto have a good knowledge of the anatomy of the crown of the tooth being preparedfor a cavity. One should visualize the extent of decayin relationship to the pulp horns and the pulp cavity. While a periapical film is always helpful , a bite-wing film of posterior teeth is even more helpful in this connection as it more accurately shows the relationship of the pulp cavity to the bulk of dentin and the cavity of the tooth. The location of the pulp horns, proximity of cavity to roof and walls of pulp chamber, etc., are important landmarks to be observedon the radiograph during cavity preparation if injury to the pulp is to be prevented. Iatrogenic causesof pulp injury which should be avoided may be mentionedhere, i .e. , physical, chemical, and bacterial causes.A few of theseare: heat from cavity preparation, which can be avoided by an adequatestreamor spray of water; heat from setting of zinc phosphatecement, which can be avoided by slow incorporation of pow&r into liquid and spreading out the cement over a large area on the slab during mixing; or heat from
450
Oral Surg. March, 1978
Grossman
polishing a restoration, which can be prevented by short, intermittent contact of the polishing agent with the tooth. Chemical agentscan also causeiatrogenic damageto the pulp. For example, the application of a dehydrating agent to the dentin, or an acid cleansing agent prior to the application of a composite restoration, or phosphoric acid from poorly mixed zinc phosphate cement, or excessive monomer or other liquid in acrylic or composite restorative materials, etc. Residual debris from cavity preparation, which has not beenentirely washedout of the cavity, may eventually causepulp irritation becauseof its bacterial content. To avoid pulp injury in shallow cavities a cavity liner should be used. While varnishes offer somedegreeof protection, they cannot be relied upon. A lattice-work of open spaces which do not protect the pulp occurs once the solvent of the varnish evaporates.A baseof zinc oxide-eugenol is preferable to a varnish. In deepcavities, indirect pulp capping should be done, i.e., the application of calcium hydroxide or zinc oxide-eugenol, preferably the former, followed by a base of zinc phosphatecement, over which a restoration is placed. PULP CONSERVATION
(EXPOSURE): THIRD LINE OF DEFENSE
The third line of defenseis aimed at saving the pulp after an exposureby pulp capping, or saving most of it by pulpotomy in young teeth. Despite meticulous care there will still be some occasions when the pulp is exposed either in the course of removing carious dentin or from traumatic injury. Pulp capping of adult teeth is a debatableprocedurein the minds of some clinicians. Oral pathologists, however, feel that it should be a successful operation in many casesbecause,even in the presenceof an exposedpulp, infection is limited to the areaof exposure. In other words, most of the pulp is uninfected and healthy except near the exposedarea, and the pulp should respondto treatmentrather than opt for its removal. From a preventive standpoint, whenevera pulp exposureis anticipated during removal of caries, the rubber dam should first be applied to prevent contamination from saliva, and as aseptic an operation as possible should be carried out so that if the pulp is exposedit does not become grossly infected. Where the pulp is exposed in young teeth, a pulpotomy is preferable to a complete pulp extirpation. It follows the adagethat half a loaf is better than none, and half a pulp is better than none. No one can fill a root canal with a pulp substitute as well as the original pulp does. Pulpotomy has several advantagesover pulpectomy: it is a simple operation which can be completed in one visit, and there am no risks of perforation, instrument fracture, irritation from medicaments,or overfilling of the canal. It is also economical of time and cost to the patient. In the event that the pulpotomy operation is not successful, pulpectomy can still be done. In this way we can prevent a vital tooth from becoming a devitalized tooth. ROOT CONSERVATION:
FOURTH LINE OF DEFENSE
The final line of defense in prevention of tooth loss, for the most part, consists of conventional root canal treatment and, in part, it consists of a rear-guard action against tooth loss by meansof endodontic surgery, hemisection, an endodontic implant, or intentional replantation. We must do everything we can to prevent the need for the last line of defense. Where the pulp has becomegrossly infected, or where the pulp has died, root canal treatment is, of course, indicated. At times, the pulp may be intentionally removed to
Volume 45 Number 3
Preventive endodontics in maintenance of teeth
451
prevent the further development of disease, as in the case of internal resorption, or intentionally removed as a preventive measureduring apical periodontal curettement to prevent the pulp from becoming infected and needing to be removed afterward. Conservative endodontic treatment is generally a successful operation, especially when bone involvement is not severe. Every effort should therefore be made to institute endodontic treatment as early as possible when it is indicated, to prevent the infection from spreading to the adjacent bone. When a large areaof rarefaction is present, the successrate by conservativetreatment alone is reduced, and root resection and/or curettement may be necessaryto save the tooth. It has been shown by Eggink,’ Grossmanand associates,’H6rting-Hansen,3 and Strindberg5 that the larger the area of rarefaction the less favorable is the prognosis by conservative treatment alone. In such casesendodontic treatment and curettement of the apical soft tissue is necessaryto bring about repair of the destroyed bone. In somecases where complete accessto the root canals is not possible becauseof partial calcification, dilaceration, fractured instrument, etc., resection and obturation of the root apex with amalgam will preclude the need for extraction of the tooth. At times, one root of a multirooted tooth is treatable endodontally while the other is not, or one root is severely involved by periodontal diseaseand the other is not. Endodontic treatment may be carried out on the sound root in such caseswhile the diseasedroot is sacrificed.The need for a bridge over a large span is thus obviated, and in somecasesit may make it possible to case-plana bridge, whereasif the tooth were extracted a denture would become necessary. The relationship between endodontics and periodontics is a close one becauseof the root canal system interwining the two. In certain casesit may be desirable to devitalize a tooth with the object of making an endodontic implant in order to stabilize the tooth and prolong its function. While this may be regarded as a radical means of endodontic prevention, it is neverthelessjustified as it prevents loss of the tooth, and often it is one which is not easily replaced . Finally, as a last resort, where a molar tooth cannot be treated by routine endodontic meansand a root resection is refused by the patient becauseof the risk of parasthesia,an intentional replantation can be done in order to prevent the tooth from being lost. By this operation the tooth is removed under aseptic precautions, the apices are clipped off, the root ends are filled with amalgam, and the tooth is replanted. The operation is successful in about 75 per cent of casesand records have shown that such teeth can be retained in function for as much as 20 or more years. REFERENCES 1. Eggink, C. 0.: Results of Endodontic Treatment Based on a Standardized Evaluation, Utrecht, 1964, Schotanus en Jens, p. 208. 2. Grossman, L. I., Shepard, L. I., and Pearson, L. A.: Roentgenologic and Clinical Evaluation of Endodontitally Treated Teeth, ORAL SURG. 17: 368-374, 1963. 3. Hofling-Hansen, E.: Studies of Implantation of an Organic Bone in Cyst Jaw Lesions, Dissertation, Copenhagen, 1970, Ejnar Munksgaards. 4. Loeb, M.: Lecture before Dental Alumni Society, School of Dental Medicine, University of Pennsylvania, 1943. 5. Strindberg, L.: The Dependence of the Results of Pulp Therapy on Certain Factors, Acta Odont. Stand. 14: Suppl. 21, p. 100, 1956. Reprint
requests to.
Dr. Louis I. Grossman, School of Dental Medicine University of Pennsylvania, Philadelphia, Pa. 19 174
MILTON SISKIN, D.D.S. Collegeof Dentistry The Universityof Tennessee 847 MonroeAvenue Memphis,Tennessee 38163
Role of preventive endodontics in maintenance of the teeth Louis I. Grossman, D.D.S., Dr.med.dent., Philadelphia, SCHOOL
OF DENTAL
MEDICINE,
UNIVERSITY
Pa.
OF PENNSYLVANIA
Preventive measuresin order to prevent decay and retain a healthy pulp are described,proceduresare outlined which prevent pulp irritation and pulp exposure so as to conserve its integrity, and endodontic proceduresto preservethe tooth either by conservative or surgical means,and so prevent its loss, are presented.
T here is an old saying, “To
prevent a big tear, sew a little one.” The little tear in dentistry is incipient caries; the big one is periapical involvement which may lead to loss of the tooth. Both the little tear and the big one can be prevented. Whatever protects against caries protects the pulp and precludes the need for endodontic treatment. Today, more than ever before, it is within the ability of the general practitioner to prevent loss of teeth. A number of years ago, before treatment with fluorides becamea reality, Loeb4 of New Haven showed statistically that periodic professional care and preventive home care could reduce the incidence of decay and loss of teeth. Loeb was an earnest general practitioner whose successin preventing decay and saving teeth for his patients was due to a personal education program in caries prevention basedon what was known at that time. With an increasein knowledge and meansto prevent decay since that time, we can expect an even higher successrate in preventing decay and endodontic involvement which may lead to loss of teeth. CROWN PROTECTION:
FIRST LINE OF DEFENSE
Preventive endodontics begins with preservation of the integrity of the enamelprotection against decay and trauma. Let us consider the factors that could be used to protect the crown of the tooth. Fluoridation of the community water supply, in which the general dentist has only a passiverole, is statedto reducecaries by 60 per cent and topical application of fluorides, in which he has an active role, is expectedto reduce it by 3.5per cent. Tooth brushing with a fluoride dentifrice and daily mouth rinsing with a 0.3 per cent 448
0030-4220/78/0345-044448$00.40/O
0
1978 The C. V. Mosby Co.
Volume 45 Number3
Preventive endodontics in maintenance of teeth
449
neutral fluoride solution will help to reduce the incidence of decay appreciably. An adhesiveplastic sealantapplied by the dentist to the occlusal surfacesof teeth also offers protection against decay. Restriction of fermentable carboyhydrates and reasonableavoidance of sticky, pasty foods, which contribute to the formation of plaque, will help to prevent decay and periodontal diseaseas well. Limiting the intake of food, which meansno snacking, will also limit the number of times acids can develop on the tooth surface. Periodic prophylaxis and examination by the dentist or hygienist will do much to detect incipient decay, or decalcified “white spots” on enamel. Such areasmust be filled promptly to prevent them from becoming larger, and an effort should be madeto recalcify decalcified areas. A word should be said about trauma which may lead to endodontic treatment or even loss of a tooth. Dentists have beenremiss in advising their young patients who participate in sports, and adults who work in industry, what to do to prevent fracture of the crown or root, or avulsion, of an anterior tooth. All too few young people wear some means of protection to the mouth during sport activities, such as a simple intermaxillary mouth guard. In addition, those with an overjet or an open bite are particularly subject to traumatic injury becauseof lack of adequatecoverage of the teeth by the lips. Men and women working with tools in industry are also subjectto accidentalinjury of the teeth and should be advised how to prevent such accidents. Furthermore, the general public is innocently ignorant of what to do if a tooth is avulsed becauseof the lack of an advisory educational campaign by the dental profession. Many avulsed teeth would serve out their natural life-span if only the patient knew what to do, and what not to do, when a tooth is avulsed. The best treatment, in essence,is to wash the tooth and immediately replace it in its socket, to be treated later by the dentist; the next best procedure is to hold it in the vestibule of the mouth and then have it replanted by the dentist; another satisfactory method is to place the tooth in a cup of water and have it replanted by the dentist; and the worst procedure is to wrap it in a handkerchief, tissue paper, or cotton, as this dries out and kills the cells of the periodontal ligament so that the tooth later becomesankylosed and mobile. PULP PROTECTION (NO EXPOSURE): SECOND LINE OF DEFENSE
The secondline of defenseis pulp protection. When the enamelhasbeenpenetratedby caries we must think in terms of protecting the pulp. This involves a number of do’s and dont’s. One needsto have a good knowledge of the anatomy of the crown of the tooth being preparedfor a cavity. One should visualize the extent of decayin relationship to the pulp horns and the pulp cavity. While a periapical film is always helpful , a bite-wing film of posterior teeth is even more helpful in this connection as it more accurately shows the relationship of the pulp cavity to the bulk of dentin and the cavity of the tooth. The location of the pulp horns, proximity of cavity to roof and walls of pulp chamber, etc., are important landmarks to be observedon the radiograph during cavity preparation if injury to the pulp is to be prevented. Iatrogenic causesof pulp injury which should be avoided may be mentionedhere, i .e. , physical, chemical, and bacterial causes.A few of theseare: heat from cavity preparation, which can be avoided by an adequatestreamor spray of water; heat from setting of zinc phosphatecement, which can be avoided by slow incorporation of pow&r into liquid and spreading out the cement over a large area on the slab during mixing; or heat from
450
Oral Surg. March, 1978
Grossman
polishing a restoration, which can be prevented by short, intermittent contact of the polishing agent with the tooth. Chemical agentscan also causeiatrogenic damageto the pulp. For example, the application of a dehydrating agent to the dentin, or an acid cleansing agent prior to the application of a composite restoration, or phosphoric acid from poorly mixed zinc phosphate cement, or excessive monomer or other liquid in acrylic or composite restorative materials, etc. Residual debris from cavity preparation, which has not beenentirely washedout of the cavity, may eventually causepulp irritation becauseof its bacterial content. To avoid pulp injury in shallow cavities a cavity liner should be used. While varnishes offer somedegreeof protection, they cannot be relied upon. A lattice-work of open spaces which do not protect the pulp occurs once the solvent of the varnish evaporates.A baseof zinc oxide-eugenol is preferable to a varnish. In deepcavities, indirect pulp capping should be done, i.e., the application of calcium hydroxide or zinc oxide-eugenol, preferably the former, followed by a base of zinc phosphatecement, over which a restoration is placed. PULP CONSERVATION
(EXPOSURE): THIRD LINE OF DEFENSE
The third line of defenseis aimed at saving the pulp after an exposureby pulp capping, or saving most of it by pulpotomy in young teeth. Despite meticulous care there will still be some occasions when the pulp is exposed either in the course of removing carious dentin or from traumatic injury. Pulp capping of adult teeth is a debatableprocedurein the minds of some clinicians. Oral pathologists, however, feel that it should be a successful operation in many casesbecause,even in the presenceof an exposedpulp, infection is limited to the areaof exposure. In other words, most of the pulp is uninfected and healthy except near the exposedarea, and the pulp should respondto treatmentrather than opt for its removal. From a preventive standpoint, whenevera pulp exposureis anticipated during removal of caries, the rubber dam should first be applied to prevent contamination from saliva, and as aseptic an operation as possible should be carried out so that if the pulp is exposedit does not become grossly infected. Where the pulp is exposed in young teeth, a pulpotomy is preferable to a complete pulp extirpation. It follows the adagethat half a loaf is better than none, and half a pulp is better than none. No one can fill a root canal with a pulp substitute as well as the original pulp does. Pulpotomy has several advantagesover pulpectomy: it is a simple operation which can be completed in one visit, and there am no risks of perforation, instrument fracture, irritation from medicaments,or overfilling of the canal. It is also economical of time and cost to the patient. In the event that the pulpotomy operation is not successful, pulpectomy can still be done. In this way we can prevent a vital tooth from becoming a devitalized tooth. ROOT CONSERVATION:
FOURTH LINE OF DEFENSE
The final line of defense in prevention of tooth loss, for the most part, consists of conventional root canal treatment and, in part, it consists of a rear-guard action against tooth loss by meansof endodontic surgery, hemisection, an endodontic implant, or intentional replantation. We must do everything we can to prevent the need for the last line of defense. Where the pulp has becomegrossly infected, or where the pulp has died, root canal treatment is, of course, indicated. At times, the pulp may be intentionally removed to
Volume 45 Number 3
Preventive endodontics in maintenance of teeth
451
prevent the further development of disease, as in the case of internal resorption, or intentionally removed as a preventive measureduring apical periodontal curettement to prevent the pulp from becoming infected and needing to be removed afterward. Conservative endodontic treatment is generally a successful operation, especially when bone involvement is not severe. Every effort should therefore be made to institute endodontic treatment as early as possible when it is indicated, to prevent the infection from spreading to the adjacent bone. When a large areaof rarefaction is present, the successrate by conservativetreatment alone is reduced, and root resection and/or curettement may be necessaryto save the tooth. It has been shown by Eggink,’ Grossmanand associates,’H6rting-Hansen,3 and Strindberg5 that the larger the area of rarefaction the less favorable is the prognosis by conservative treatment alone. In such casesendodontic treatment and curettement of the apical soft tissue is necessaryto bring about repair of the destroyed bone. In somecases where complete accessto the root canals is not possible becauseof partial calcification, dilaceration, fractured instrument, etc., resection and obturation of the root apex with amalgam will preclude the need for extraction of the tooth. At times, one root of a multirooted tooth is treatable endodontally while the other is not, or one root is severely involved by periodontal diseaseand the other is not. Endodontic treatment may be carried out on the sound root in such caseswhile the diseasedroot is sacrificed.The need for a bridge over a large span is thus obviated, and in somecasesit may make it possible to case-plana bridge, whereasif the tooth were extracted a denture would become necessary. The relationship between endodontics and periodontics is a close one becauseof the root canal system interwining the two. In certain casesit may be desirable to devitalize a tooth with the object of making an endodontic implant in order to stabilize the tooth and prolong its function. While this may be regarded as a radical means of endodontic prevention, it is neverthelessjustified as it prevents loss of the tooth, and often it is one which is not easily replaced . Finally, as a last resort, where a molar tooth cannot be treated by routine endodontic meansand a root resection is refused by the patient becauseof the risk of parasthesia,an intentional replantation can be done in order to prevent the tooth from being lost. By this operation the tooth is removed under aseptic precautions, the apices are clipped off, the root ends are filled with amalgam, and the tooth is replanted. The operation is successful in about 75 per cent of casesand records have shown that such teeth can be retained in function for as much as 20 or more years. REFERENCES 1. Eggink, C. 0.: Results of Endodontic Treatment Based on a Standardized Evaluation, Utrecht, 1964, Schotanus en Jens, p. 208. 2. Grossman, L. I., Shepard, L. I., and Pearson, L. A.: Roentgenologic and Clinical Evaluation of Endodontitally Treated Teeth, ORAL SURG. 17: 368-374, 1963. 3. Hofling-Hansen, E.: Studies of Implantation of an Organic Bone in Cyst Jaw Lesions, Dissertation, Copenhagen, 1970, Ejnar Munksgaards. 4. Loeb, M.: Lecture before Dental Alumni Society, School of Dental Medicine, University of Pennsylvania, 1943. 5. Strindberg, L.: The Dependence of the Results of Pulp Therapy on Certain Factors, Acta Odont. Stand. 14: Suppl. 21, p. 100, 1956. Reprint
requests to.
Dr. Louis I. Grossman, School of Dental Medicine University of Pennsylvania, Philadelphia, Pa. 19 174