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Antibiotic resistance of microorganisms isolated from root canals
Antibiotic resistance of microorganisms isolated from root canals Julius Fox, D.D.S.,” and Henry New Hyde Park, N. Y.
D. Issenberg, Ph.D.,‘*
THE LONG ISLAND JEWISH HOSPITAL
C
riticism of the use of antibiotics in dentistry suggests re-evaluation of the place of these drugs in the practice of endodontics.‘? 2 It is generally conceded that there is a connection between the indiscriminate administration o#f antibiotics and the emergence of resistant bacterial strains. In addition, allergic reactions and toxic effects have been documented extensively; fungus overgrowth and superinfections have been reported frequently as a result of the administration of antibiotics, both parenterally and by mouth.3-10 Although these problems are rarely ascribed to the use of antibiotics in endodontic therapy, some cases have been reported in the dental literature.ll-l’ This investigation was undertaken to study the bacterial populations of infected root canals and their antibiotic-resistance patterns. MATERIAL AND METHOD
Both private practice and outpatient hospital caseswere accepted, at random, for this study. There was no attempt at case selection. The endodontic problems ranged from carious exposure of a vital pulp to teeth exhibiting periapical areas of radiolucency and fistulas. A standardized endodontic technique was followed in all instances. This included isolation by rubber dam, complete caries removal, irrigation with 5 percent sodium hypochlorite, sterilization of all instruments to be employed, and double sealing of the cavity at the completion of each treatment. Two different types of dressing were used between treatments. Teeth with vital pulps were dressed with eugenol, and in all other eases PBSC was used. The latter, a polyantibiotic-antifungal mixture described by Grossman,15con*In charge of Endodontics, Department of Dentistry. **Microbiologist, Department of Laboratories.
230
Volume 23 Number 2
Antibiotic
resistance of root-canal microorganisms
231
tains penicillin, streptomycin, bacitracin, and sodium caprylate. All dressings were placed in the pulp chamber, covered with a sterile cotton pellet, and double sealed. Absorbent points were not placed in the root canals between visits. Cultures were taken at the beginning and end of each treatment session. Where PBSC had been employed as a dressing, the first three absorbent points were discarded and the fourth point was used for culturing, as suggested by Bender and Seltzer,“j to minimize the incidence of false negative cultures. Treatment was completed (root canals filled) when the posttreatment culture of the previous visit was reported negative and the tooth was asymptomatic. The culture medium utilized was trypticase soy broth (Baltimore Biological Laboratories) with 0.1 per cent agar, dispensed in 10 ml. amounts in screw-capped tubes, as suggested by Leavitt and associatesl’ All tubes were incubated at 3’7” C. for 7 days after inoculation and examined daily, Negative results were accepted only at the end of this time. The culture medium employed permits growth of aerobic and anaerobic microorganisms. All subcultures were incubated under both aerobic and anaerobic conditionsl’l 33v35 All tubes exhibiting growth of microorganisms were treated, as described by Isenberg and Karelitz,18 by isolating the microorganisms on a variety of aerobic and anaerobic enrichment media after the method of Isenberg and Berkman.3’ Further studies of the biochemical, physiologic, and immunochemical properties of the isolated microorganisms were carried out in order to identify them in keeping with the taxonomic criteria of Bergey’s Manud.1s Antibiotic-susceptibility profiles of the identified microorganisms were determined on Toxoid susceptibility agar (Consolidated Laboratories) with dry paper disks containing high concentrations of antibiotics, in keeping with the concepts of Rodger and associates.2o
Table I. Total organisms isolated Organism
Number of positive cultures
Viridans streptococci Enterococms sp. Staphylococw epidermidis Btaphylooocws am-em Elebsiella sp. Candick a&cans Bacillus sp. Protew sp. Clostridium sp. RhoaotoTula sp. Escheriohia coli Hafitia sp. Psevdomonas aerw@aosa Neissmia sp.
204 84 57 10
8
; 2 : 1 1 i Totals
Mixed
381
oultures
Two organisms Three organisms
27 5
232 Table
O.H., ox.
Pox and Isefnberg II. Resistance patterns
(Numerals
represent
number -.---
Organism Viridans streptococci Enterowcous sp. Staphylowcou epidermidis Staphylococcus auwus Elebsiella sp. Protew? sp.
cl0striah
& 02.
February,
Eruthromycin 3 4 3 8 2
of ca.ses of resistant
-___-
i Chlortetmqcline
Chlor/ ampheGco1
1 1 5
4
1
3
/ Penidllin
1
sp.
Escheri&& coli Hafnti sp. Pseudomona aeruginosa
1
1
microdntibotic ~--
1
I
Neomycin 101 24 4
196i
1
All patients included in this report gave a normal medical history at the time of treatment. While some had received various antibiotics during the previous 6 months, no antibiotics had been administered during the week immediately preceding treatment. Twenty-two teeth with initially positive cultures were used as controls. Only sterile distilled water was used for irrigation, and a sterile, dry cotton pellet was sealed in the pulp chamber between treatments. A total of sixty-one teeth in fifty-eight patients, yielding 381 positive cultures, were utilized in this investigation. Our findings are shown in Tables I, II, and III. DISCUSSION
Numerous studies of the bacterial flora of infected root canals have been published,22-35 as have several studies of antibiotic resistance.z4j 31134*36 Our findings of the microbial population generally tend to agree with these except in the high incidence of enterococci which, in this study, were second only to the viridans streptococci. Also, the percentage of mixed cultures of two or more organisms was less than that reported by other authorsZ3* 24p=L 2s,33 Some of the resistance patterns were completely at variance with previous studies cited.“9 31,w 36We found no viridans streptococci resistant to penicillin. The incidence of resistance to streptomycin, however, among both staphylococci and enterococci was extremely high. The resistance of streptococci to streptomycin and of staphylococci to penicillin was found to be within the limits stated by others. The majority of these cases, while exhibiting growth of microorganisms at the first (pretreatment) culture, became negative by the end of the first visit as a result of our chemomechanical treatment. They remained negative, in both pre- and posttreatment cultures, at the second visit and were completed at the third visit. Among the control cases, in which no medication was employed, more than half required four or more treatments before completion. In some of these, PBSC was used as a dressing after two or three visits when a fistula remained open despite negative cultures or persistently positive cultures were encountered.
eit 2 i 1 1 1
Volume 23 Number 2
Antibiotic
resistance of root-canal
nGcroorganisms 233
organisms)
Table III. Multiple resistance Resistance Not resistant to any antibiotic Resistant to 1 antibiotic Resistant to 2 antibiotics Resistant to 3 antibiotics Resistant to 4 or more sntibiotiw
Organisms 41 48 69 56 62
In most instances such treatment effected closure of the fistula and/or led to a negative culture within one or two additional treatments. There were, however, several casesin which PBSC did not eliminate the positive cultures despite the fact that the identified microorganisims were susceptible to both penicillin and streptomycin by our methods. In a small group of casesbacterial flora changed from treatment to treatment and occasionally, even where the microorganisms remained constant, there were changes in resistance patterns. There was no single antibiotic of those tested, including several recently developed ones, to which one or more of the microorganisms were not resistant. A very small number of microorganisms tested were not resistant to any of the antibiotics. We agree with JawetzW statement: “The microbial world has responded to the introduction of antimicrobial substances into its ecological balance in a variety of ways. It is apparent that the indiscriminate use of antimicrobial drugs by doctors everywhere has vitiated their benefits . . . . it is becoming increasingly more apparent that the administration of antibiotics without definite indication has very definite harmful effects.” Nevertheless, there does appear to be a place for antibiotic therapy in endodontics. PBSC, while certainly effective, is a nonspecific remedy, a combination of antibiotics and a fungicide, designed to include all potential oral microorganisms in its spectrum. However, in view of all the problems inherent in the administration of antibiotics, it may prove eventually to be deleterious, from the long-range point of view, when used routinely ami indiscriminately.
234
Fox and Isenberg
O.S., O.M. & 0.1’. February, 1967
It must be understood that PBSC ws in 110 14~~ being tested in this study. In fact, bacitracin and sodium caprylate, two of its ingredients, were not normally available through the hospital’s pharnmcy; hence, the Department of Laboratories did not include them in its rout.ine testing procedures. At. the time of this study, and for several years prior to that time, the clinician involved had been using PBS(,Y as a routine dressing in all cases involving nonvital pulps, both in his private practice and in bhe hospital clinic, with excellent clinical results. It is for this reason alone that PBSC is mentioned in the present article. This routine practice has since been discontinued. In a personal communication, Grossman specifies that in more than a decade of USC of PBSC at the Endodontic Clinic of the University of Pennsylvania, no organism isolated from a root canal has proved to be resistant to PBSC. Goldman and Pearson36 indicate that antibiotic-susceptibility studies may be readily incorporated in a dental office routine. In view of the average dentist’s lack of familiarity with modern microbiologic procedures, this might better be carried out in conjunction with an approved microbiology laboratory. We believe that antibiotics should be used in endodontics, as in other fields of medicine and dentistry, only after identification and susceptibility studies have been performed, so that the proper antibiotic may be selected for maximum effectiveness. In the interim required for these studies, treatment with the time-honored nonspecific chemical agents may be employed. If there is laboratory or clinical evidence of the inadequacy of these chemical agents, t,reatment, with specific antibiotics, in adequate doses, may then be instituted. SUMMARY 1. The problems associated with antibiotics have been described. 2. In the present study 381 positive cultures from root canals were processed for identification and for antibiotic-susceptibility patterns of the involved microorganisms. 3. Tables are presented to show the microorganisms isolated and their resistance patterns. 4. The findings are discussed in the light of clinical practice and adaptability to office routine. 5. A plea is made for the rational, controlled use of antibiotics rather than indiscriminate abuse of these agents. REFERENCES
1. Lane, Stanley L.: Review of Current Opinion on the Hazards of Indiscriminate Antibiotic Therapy in Dental Practice, ORAL Sum., ORAL MED. & ORAL PATH. 9: 952, 1956. 2. Behrm-n, Stanley J. : The Development of Antibiotic-Resistant Organisms : Its Significance to the Dentist, New York State D. J. 21: 297, 1955. 3. Jawetz, E.: Patient, Doctor, Drug and Bug, New England J. Med. 258: 785, 1958. 4. Caswell, H. T., Schreck, K. M., and others: Bacterial Logic and Clinical Experiences and the Methods of Control of Hospital Infections Due to Antibiotic Resistant Staphylococci, Surg. Giynec. & Obst. 106: 1, 1958. 5. Isenberg, H. D., Piasano, M. A., Carito, S., and Berkman, J. I.: Factors Leading to Overt Monilial Disease, Antibiotics & Chemother. 10: 353, 1960. 6. Hussar, A. E.: Deaths From Antibiotics, J. D. Med. 11: 29, 1956 (taken from J. A. M. A. 168: 1330, 1955). 7. Lowell, F. C.: Allergic Reactions to Sulfonamide and Antibiotic Drugs, Ann. Int. Med. 43: 333, 1955.
Adibiotic
Volume 23 Number 2
resistance of root-canal microorganisms
235
Toxicity of Antibacterial Drugs: A A. H., and Lane, 5. L.: The Clinical Comparative Review of the Literature Based on 96,075 Cases Treated With Sulfonamides and Antibiotics, ORAL SURG.,ORAL MED. & ORAL PATH. 6: 347, 1952. Therapy, ORAL SURQ., 9. Bartels, H. A. : Monilial Infection of the Mouth Following Antibiotic
8. :Kutscher,
ORAL MED. & ORAL PATH. 6: 790,1953.
Complicating 10. Woods, J. W., Manning, I. H., Jr., and Patterson, C. N.: Monilial Infections Therapeutic Use of Antibiotics, J. A. M. A. 145: 207, 1951. With Bacitracin-Neomycin as 11. Pirila, V., and Rantanen, A. B.: Root Canal Treatment Cause of Flare-up of Allergic Eczema, ORAL SURG., ORAL MED. & ORAL PATH. 13: 589,
1960. and Disadvantages of the Use of Antibiotics 12. Bender, I. B., and Seltzer, S.: Advantages in Endodontia, ORAL SURG.,ORAL MED. & ORAL PATH. 7: 993, 1954. Compound for Root Canal Medication, 13. Stewart, G. G. : Improved Antibiotic-Antihistamine J. D. Med. 9: 174, 1954. Root Canal Dressing, 14. Fox, J., and Moodnik, R. M.: Systemic Reaction to Polyantibiotic New York State D. J. 30: 282-283, 1964. Treatment of Pulpless Teeth, J. Am. Dent. A. 43: ‘265, 15. Grossman, I,. I.: Polyantibiotic 1951. of Error of the Negative Culture with 16. Bender, I. B., and Seltzer, S.: The Probability the Use of Combinations of Antibiotics in Endodontic Treatment, ORAL SURG.,ORAL MED.
& ORAL PATH. 7: 1311-1319. 1954. 17. Leavitt, J. M., Naidorf, I. J., and Shugaensky, 18. 19.
P.: A Sensitive Culture Medium for the Detection of Both Aerobes and Anaerobes, New York J. Dent. 25: 379, 1955. Isenberg, H. D., and Karelitz, S.: Clinical and Laboratory Evaluation of Triacetyloleandomycin in a Variety of Pyogenic Infections. Welch, H., and Mart&Ibafiey, F. (editors) : Antibiotics Annual, 195859, New York, 1959, Medical Encyclopedia, Inc., pp. 284-286. Breed, R. S., Murray. E. G. D.. and Smith, N. R.: Beraev’s Manual of Determinative Bacterioloev: ed. 7. Baltimore. 1957. Williams & Wilkins C&uanv. Rodger, K. C., B’ranch, A., ‘Bower, E. E., Starkey, D. H., Gregory, E., Murray, R. D., and Harrop, J.: Antibiotic Therapy: Correlation of Clinical Results With Laboratory Sensitivity Tests, Canad. M.A.J. 74: 635-612, 1956. Jawetz, E. : The Rational Use of Antimicrobial Agents: Reason Versus Emotion in Chemotherapy, ORAL SURG.,ORAL MED. & ORAL PATH. 8: 982, 1955. of Newer Methods to Study the Crawford, J. J., and Shankle, R. J.: Application Importance of Root Canal and Oral Microbiota in Endodontics, ORAL SURG.,ORAL MED. & U”
20. 21. 22.
I
ORAL PATH. 14: 1109-1123, 1961. 23. Sciaky, I., and Sultzenu, A.: The Bacterial Flora of Diseased Pulp, J. D. Med. 16: 185-189, 1961. 24. Alin, K., and Agren, E.: The Bacterial Flora of Odontogenic Infections and Its Sensitivity to Antibiotics, Acta odont. scandinav. 12: 85-98, 1954. 25. Bleckman, H.: Bacteriology in Endodontic Treatment, D. Clin. North America, pp. 845. 854, November, 1957. 26. Winkler. K. C.. and Van Ameroneen. J.: Bacterioloaic ‘Results From 4.000 Root Canal ' Cultures; ORAL BURG.,ORAL MED. GOkit PATH. 12: 8371875, 1959. 27. Van Amerongen, J., Eggink, C. 0.. and Lamera. A. C.: The Bacteriological Control of Endodont,ic Treatment. yiidschr. v. ‘Tand. 65: 65-75. 1959. 28. Melville, T. H., and Siack; G. L.: Bacteria Isolated ‘From Root Canals During Endodontic Treatment, Brit. D. J. 110: 127-136, 1961. 29. Shovelton, D. S., and Sidaway, D. A.: Infection in Root Canals, Brit. D. J. 108: 115-118, 1960. 30. Cohen, M. M., Joress, S. M., and Calisti, L. P.: Bacteriologic Study of Infected Deciduous Molars, ORAL SURG.,ORAL MED. & ORAL PATH. 12: 1382-1386, 1960. lnto the Bacteriological Control of Infected Root Canals, 31. Hobson, P. : An Investigation Brit. D. J. 106: 63-70, 1959. 32. Cran, J. A.: A Study of the Pathology and Bacteriology of the Pulpless Tooth and Its Bearing on Treatment (Part II), Australian J. Dent. 59: 82-84, 1955. 33. Cobe, H. M., Chilton, N. W., and Kaufman, H.: Evaluation of a Dual Culture Medium for Endodontics, New York State D. J. 23: 371-374. 1957. 34. Slack, G. L.: The Resistance to Antibiotics of Micro-organisms Isolated From Root Canals. Brit. D. J. 104: 493-494. 19.57. 35. Leavitt, J. M., Naidorf, I. J., and Shugaevsky, P.: The Bacterial Flora of Root Canal as Disclosed by a New Culture Medium for Endodontics, ORAL BURG., ORAL MED. &
ORAL PATH. 11: 302-308,1958.
36. Goldman., M., and Pearson, A. H.: A Clinical Study of the Use of Antibiotic Sensitivity Testing in Endodontics, ORAL BURG.,ORAL MED. & ORAL PATH. 15: 1250-1258, 1962. 37. Isenberg, H. D., and Berkman, J. I.: Microbial Diagnosis in a General Hospital, Ann. New York Acad. SC. 98: 647, 1963.
D. Issenberg, Ph.D.,‘*
THE LONG ISLAND JEWISH HOSPITAL
C
riticism of the use of antibiotics in dentistry suggests re-evaluation of the place of these drugs in the practice of endodontics.‘? 2 It is generally conceded that there is a connection between the indiscriminate administration o#f antibiotics and the emergence of resistant bacterial strains. In addition, allergic reactions and toxic effects have been documented extensively; fungus overgrowth and superinfections have been reported frequently as a result of the administration of antibiotics, both parenterally and by mouth.3-10 Although these problems are rarely ascribed to the use of antibiotics in endodontic therapy, some cases have been reported in the dental literature.ll-l’ This investigation was undertaken to study the bacterial populations of infected root canals and their antibiotic-resistance patterns. MATERIAL AND METHOD
Both private practice and outpatient hospital caseswere accepted, at random, for this study. There was no attempt at case selection. The endodontic problems ranged from carious exposure of a vital pulp to teeth exhibiting periapical areas of radiolucency and fistulas. A standardized endodontic technique was followed in all instances. This included isolation by rubber dam, complete caries removal, irrigation with 5 percent sodium hypochlorite, sterilization of all instruments to be employed, and double sealing of the cavity at the completion of each treatment. Two different types of dressing were used between treatments. Teeth with vital pulps were dressed with eugenol, and in all other eases PBSC was used. The latter, a polyantibiotic-antifungal mixture described by Grossman,15con*In charge of Endodontics, Department of Dentistry. **Microbiologist, Department of Laboratories.
230
Volume 23 Number 2
Antibiotic
resistance of root-canal microorganisms
231
tains penicillin, streptomycin, bacitracin, and sodium caprylate. All dressings were placed in the pulp chamber, covered with a sterile cotton pellet, and double sealed. Absorbent points were not placed in the root canals between visits. Cultures were taken at the beginning and end of each treatment session. Where PBSC had been employed as a dressing, the first three absorbent points were discarded and the fourth point was used for culturing, as suggested by Bender and Seltzer,“j to minimize the incidence of false negative cultures. Treatment was completed (root canals filled) when the posttreatment culture of the previous visit was reported negative and the tooth was asymptomatic. The culture medium utilized was trypticase soy broth (Baltimore Biological Laboratories) with 0.1 per cent agar, dispensed in 10 ml. amounts in screw-capped tubes, as suggested by Leavitt and associatesl’ All tubes were incubated at 3’7” C. for 7 days after inoculation and examined daily, Negative results were accepted only at the end of this time. The culture medium employed permits growth of aerobic and anaerobic microorganisms. All subcultures were incubated under both aerobic and anaerobic conditionsl’l 33v35 All tubes exhibiting growth of microorganisms were treated, as described by Isenberg and Karelitz,18 by isolating the microorganisms on a variety of aerobic and anaerobic enrichment media after the method of Isenberg and Berkman.3’ Further studies of the biochemical, physiologic, and immunochemical properties of the isolated microorganisms were carried out in order to identify them in keeping with the taxonomic criteria of Bergey’s Manud.1s Antibiotic-susceptibility profiles of the identified microorganisms were determined on Toxoid susceptibility agar (Consolidated Laboratories) with dry paper disks containing high concentrations of antibiotics, in keeping with the concepts of Rodger and associates.2o
Table I. Total organisms isolated Organism
Number of positive cultures
Viridans streptococci Enterococms sp. Staphylococw epidermidis Btaphylooocws am-em Elebsiella sp. Candick a&cans Bacillus sp. Protew sp. Clostridium sp. RhoaotoTula sp. Escheriohia coli Hafitia sp. Psevdomonas aerw@aosa Neissmia sp.
204 84 57 10
8
; 2 : 1 1 i Totals
Mixed
381
oultures
Two organisms Three organisms
27 5
232 Table
O.H., ox.
Pox and Isefnberg II. Resistance patterns
(Numerals
represent
number -.---
Organism Viridans streptococci Enterowcous sp. Staphylowcou epidermidis Staphylococcus auwus Elebsiella sp. Protew? sp.
cl0striah
& 02.
February,
Eruthromycin 3 4 3 8 2
of ca.ses of resistant
-___-
i Chlortetmqcline
Chlor/ ampheGco1
1 1 5
4
1
3
/ Penidllin
1
sp.
Escheri&& coli Hafnti sp. Pseudomona aeruginosa
1
1
microdntibotic ~--
1
I
Neomycin 101 24 4
196i
1
All patients included in this report gave a normal medical history at the time of treatment. While some had received various antibiotics during the previous 6 months, no antibiotics had been administered during the week immediately preceding treatment. Twenty-two teeth with initially positive cultures were used as controls. Only sterile distilled water was used for irrigation, and a sterile, dry cotton pellet was sealed in the pulp chamber between treatments. A total of sixty-one teeth in fifty-eight patients, yielding 381 positive cultures, were utilized in this investigation. Our findings are shown in Tables I, II, and III. DISCUSSION
Numerous studies of the bacterial flora of infected root canals have been published,22-35 as have several studies of antibiotic resistance.z4j 31134*36 Our findings of the microbial population generally tend to agree with these except in the high incidence of enterococci which, in this study, were second only to the viridans streptococci. Also, the percentage of mixed cultures of two or more organisms was less than that reported by other authorsZ3* 24p=L 2s,33 Some of the resistance patterns were completely at variance with previous studies cited.“9 31,w 36We found no viridans streptococci resistant to penicillin. The incidence of resistance to streptomycin, however, among both staphylococci and enterococci was extremely high. The resistance of streptococci to streptomycin and of staphylococci to penicillin was found to be within the limits stated by others. The majority of these cases, while exhibiting growth of microorganisms at the first (pretreatment) culture, became negative by the end of the first visit as a result of our chemomechanical treatment. They remained negative, in both pre- and posttreatment cultures, at the second visit and were completed at the third visit. Among the control cases, in which no medication was employed, more than half required four or more treatments before completion. In some of these, PBSC was used as a dressing after two or three visits when a fistula remained open despite negative cultures or persistently positive cultures were encountered.
eit 2 i 1 1 1
Volume 23 Number 2
Antibiotic
resistance of root-canal
nGcroorganisms 233
organisms)
Table III. Multiple resistance Resistance Not resistant to any antibiotic Resistant to 1 antibiotic Resistant to 2 antibiotics Resistant to 3 antibiotics Resistant to 4 or more sntibiotiw
Organisms 41 48 69 56 62
In most instances such treatment effected closure of the fistula and/or led to a negative culture within one or two additional treatments. There were, however, several casesin which PBSC did not eliminate the positive cultures despite the fact that the identified microorganisims were susceptible to both penicillin and streptomycin by our methods. In a small group of casesbacterial flora changed from treatment to treatment and occasionally, even where the microorganisms remained constant, there were changes in resistance patterns. There was no single antibiotic of those tested, including several recently developed ones, to which one or more of the microorganisms were not resistant. A very small number of microorganisms tested were not resistant to any of the antibiotics. We agree with JawetzW statement: “The microbial world has responded to the introduction of antimicrobial substances into its ecological balance in a variety of ways. It is apparent that the indiscriminate use of antimicrobial drugs by doctors everywhere has vitiated their benefits . . . . it is becoming increasingly more apparent that the administration of antibiotics without definite indication has very definite harmful effects.” Nevertheless, there does appear to be a place for antibiotic therapy in endodontics. PBSC, while certainly effective, is a nonspecific remedy, a combination of antibiotics and a fungicide, designed to include all potential oral microorganisms in its spectrum. However, in view of all the problems inherent in the administration of antibiotics, it may prove eventually to be deleterious, from the long-range point of view, when used routinely ami indiscriminately.
234
Fox and Isenberg
O.S., O.M. & 0.1’. February, 1967
It must be understood that PBSC ws in 110 14~~ being tested in this study. In fact, bacitracin and sodium caprylate, two of its ingredients, were not normally available through the hospital’s pharnmcy; hence, the Department of Laboratories did not include them in its rout.ine testing procedures. At. the time of this study, and for several years prior to that time, the clinician involved had been using PBS(,Y as a routine dressing in all cases involving nonvital pulps, both in his private practice and in bhe hospital clinic, with excellent clinical results. It is for this reason alone that PBSC is mentioned in the present article. This routine practice has since been discontinued. In a personal communication, Grossman specifies that in more than a decade of USC of PBSC at the Endodontic Clinic of the University of Pennsylvania, no organism isolated from a root canal has proved to be resistant to PBSC. Goldman and Pearson36 indicate that antibiotic-susceptibility studies may be readily incorporated in a dental office routine. In view of the average dentist’s lack of familiarity with modern microbiologic procedures, this might better be carried out in conjunction with an approved microbiology laboratory. We believe that antibiotics should be used in endodontics, as in other fields of medicine and dentistry, only after identification and susceptibility studies have been performed, so that the proper antibiotic may be selected for maximum effectiveness. In the interim required for these studies, treatment with the time-honored nonspecific chemical agents may be employed. If there is laboratory or clinical evidence of the inadequacy of these chemical agents, t,reatment, with specific antibiotics, in adequate doses, may then be instituted. SUMMARY 1. The problems associated with antibiotics have been described. 2. In the present study 381 positive cultures from root canals were processed for identification and for antibiotic-susceptibility patterns of the involved microorganisms. 3. Tables are presented to show the microorganisms isolated and their resistance patterns. 4. The findings are discussed in the light of clinical practice and adaptability to office routine. 5. A plea is made for the rational, controlled use of antibiotics rather than indiscriminate abuse of these agents. REFERENCES
1. Lane, Stanley L.: Review of Current Opinion on the Hazards of Indiscriminate Antibiotic Therapy in Dental Practice, ORAL Sum., ORAL MED. & ORAL PATH. 9: 952, 1956. 2. Behrm-n, Stanley J. : The Development of Antibiotic-Resistant Organisms : Its Significance to the Dentist, New York State D. J. 21: 297, 1955. 3. Jawetz, E.: Patient, Doctor, Drug and Bug, New England J. Med. 258: 785, 1958. 4. Caswell, H. T., Schreck, K. M., and others: Bacterial Logic and Clinical Experiences and the Methods of Control of Hospital Infections Due to Antibiotic Resistant Staphylococci, Surg. Giynec. & Obst. 106: 1, 1958. 5. Isenberg, H. D., Piasano, M. A., Carito, S., and Berkman, J. I.: Factors Leading to Overt Monilial Disease, Antibiotics & Chemother. 10: 353, 1960. 6. Hussar, A. E.: Deaths From Antibiotics, J. D. Med. 11: 29, 1956 (taken from J. A. M. A. 168: 1330, 1955). 7. Lowell, F. C.: Allergic Reactions to Sulfonamide and Antibiotic Drugs, Ann. Int. Med. 43: 333, 1955.
Adibiotic
Volume 23 Number 2
resistance of root-canal microorganisms
235
Toxicity of Antibacterial Drugs: A A. H., and Lane, 5. L.: The Clinical Comparative Review of the Literature Based on 96,075 Cases Treated With Sulfonamides and Antibiotics, ORAL SURG.,ORAL MED. & ORAL PATH. 6: 347, 1952. Therapy, ORAL SURQ., 9. Bartels, H. A. : Monilial Infection of the Mouth Following Antibiotic
8. :Kutscher,
ORAL MED. & ORAL PATH. 6: 790,1953.
Complicating 10. Woods, J. W., Manning, I. H., Jr., and Patterson, C. N.: Monilial Infections Therapeutic Use of Antibiotics, J. A. M. A. 145: 207, 1951. With Bacitracin-Neomycin as 11. Pirila, V., and Rantanen, A. B.: Root Canal Treatment Cause of Flare-up of Allergic Eczema, ORAL SURG., ORAL MED. & ORAL PATH. 13: 589,
1960. and Disadvantages of the Use of Antibiotics 12. Bender, I. B., and Seltzer, S.: Advantages in Endodontia, ORAL SURG.,ORAL MED. & ORAL PATH. 7: 993, 1954. Compound for Root Canal Medication, 13. Stewart, G. G. : Improved Antibiotic-Antihistamine J. D. Med. 9: 174, 1954. Root Canal Dressing, 14. Fox, J., and Moodnik, R. M.: Systemic Reaction to Polyantibiotic New York State D. J. 30: 282-283, 1964. Treatment of Pulpless Teeth, J. Am. Dent. A. 43: ‘265, 15. Grossman, I,. I.: Polyantibiotic 1951. of Error of the Negative Culture with 16. Bender, I. B., and Seltzer, S.: The Probability the Use of Combinations of Antibiotics in Endodontic Treatment, ORAL SURG.,ORAL MED.
& ORAL PATH. 7: 1311-1319. 1954. 17. Leavitt, J. M., Naidorf, I. J., and Shugaensky, 18. 19.
P.: A Sensitive Culture Medium for the Detection of Both Aerobes and Anaerobes, New York J. Dent. 25: 379, 1955. Isenberg, H. D., and Karelitz, S.: Clinical and Laboratory Evaluation of Triacetyloleandomycin in a Variety of Pyogenic Infections. Welch, H., and Mart&Ibafiey, F. (editors) : Antibiotics Annual, 195859, New York, 1959, Medical Encyclopedia, Inc., pp. 284-286. Breed, R. S., Murray. E. G. D.. and Smith, N. R.: Beraev’s Manual of Determinative Bacterioloev: ed. 7. Baltimore. 1957. Williams & Wilkins C&uanv. Rodger, K. C., B’ranch, A., ‘Bower, E. E., Starkey, D. H., Gregory, E., Murray, R. D., and Harrop, J.: Antibiotic Therapy: Correlation of Clinical Results With Laboratory Sensitivity Tests, Canad. M.A.J. 74: 635-612, 1956. Jawetz, E. : The Rational Use of Antimicrobial Agents: Reason Versus Emotion in Chemotherapy, ORAL SURG.,ORAL MED. & ORAL PATH. 8: 982, 1955. of Newer Methods to Study the Crawford, J. J., and Shankle, R. J.: Application Importance of Root Canal and Oral Microbiota in Endodontics, ORAL SURG.,ORAL MED. & U”
20. 21. 22.
I
ORAL PATH. 14: 1109-1123, 1961. 23. Sciaky, I., and Sultzenu, A.: The Bacterial Flora of Diseased Pulp, J. D. Med. 16: 185-189, 1961. 24. Alin, K., and Agren, E.: The Bacterial Flora of Odontogenic Infections and Its Sensitivity to Antibiotics, Acta odont. scandinav. 12: 85-98, 1954. 25. Bleckman, H.: Bacteriology in Endodontic Treatment, D. Clin. North America, pp. 845. 854, November, 1957. 26. Winkler. K. C.. and Van Ameroneen. J.: Bacterioloaic ‘Results From 4.000 Root Canal ' Cultures; ORAL BURG.,ORAL MED. GOkit PATH. 12: 8371875, 1959. 27. Van Amerongen, J., Eggink, C. 0.. and Lamera. A. C.: The Bacteriological Control of Endodont,ic Treatment. yiidschr. v. ‘Tand. 65: 65-75. 1959. 28. Melville, T. H., and Siack; G. L.: Bacteria Isolated ‘From Root Canals During Endodontic Treatment, Brit. D. J. 110: 127-136, 1961. 29. Shovelton, D. S., and Sidaway, D. A.: Infection in Root Canals, Brit. D. J. 108: 115-118, 1960. 30. Cohen, M. M., Joress, S. M., and Calisti, L. P.: Bacteriologic Study of Infected Deciduous Molars, ORAL SURG.,ORAL MED. & ORAL PATH. 12: 1382-1386, 1960. lnto the Bacteriological Control of Infected Root Canals, 31. Hobson, P. : An Investigation Brit. D. J. 106: 63-70, 1959. 32. Cran, J. A.: A Study of the Pathology and Bacteriology of the Pulpless Tooth and Its Bearing on Treatment (Part II), Australian J. Dent. 59: 82-84, 1955. 33. Cobe, H. M., Chilton, N. W., and Kaufman, H.: Evaluation of a Dual Culture Medium for Endodontics, New York State D. J. 23: 371-374. 1957. 34. Slack, G. L.: The Resistance to Antibiotics of Micro-organisms Isolated From Root Canals. Brit. D. J. 104: 493-494. 19.57. 35. Leavitt, J. M., Naidorf, I. J., and Shugaevsky, P.: The Bacterial Flora of Root Canal as Disclosed by a New Culture Medium for Endodontics, ORAL BURG., ORAL MED. &
ORAL PATH. 11: 302-308,1958.
36. Goldman., M., and Pearson, A. H.: A Clinical Study of the Use of Antibiotic Sensitivity Testing in Endodontics, ORAL BURG.,ORAL MED. & ORAL PATH. 15: 1250-1258, 1962. 37. Isenberg, H. D., and Berkman, J. I.: Microbial Diagnosis in a General Hospital, Ann. New York Acad. SC. 98: 647, 1963.