Identification of Cultivable Microorganisms from Primary Teeth with Necrotic Pulps

The objective of this study was to identify cultivable microorganisms from primary teeth with necrotic pulps. This experimental study included 21 patients of both sexes between 4 and 7 years of age with necrotic pulps in primary teeth. Twenty-one maxillary and mandibular molars containing at least 1 necrotic canal, an abscess or sinus tract, one or more radiolucent areas in the furcation or periapical region, teeth having at least two thirds of root length, and carious lesions directly exposed to the oral environment were included. After antisepsis of the oral cavity, anesthesia of the affected tooth, and isolation and disinfection of the operative field, 3 sterile absorbent paper points were sequentially placed for 30 seconds for the collection of samples. The samples were immediately processed in an anaerobic chamber, and all isolated microorganisms were identified. Anaerobic species (anaerobic facultative and moderate anaerobes) were isolated in all root canals; 68.4% of root canal samples studied showed a polymicrobial nature. Most of the isolate consisted of Bifidobacterium Spp2 and Streptococcus intermedius. Other less frequently encountered species were Actinomyces israelii, Bifidobacterium spp 1, Clostridium spp, and Candida albicans. Results indicate the existence of combinations of bacterial species in root canal infections of the primary dentition with necrotic pulps, anaerobic bacteria predominating.

anaerobic microorganisms, necrotic pulp, primary teeth

1. Aas JA, Paster BJ, Stokes LN. Defining the normal bacterial flora of the oral cavity. J Clin Microbiol, 43: 5721–32, 2005.

2. Sundqvist G. Ecology of the root canal flora. J Endod,18: 427–30, 1992.

3. Kakehashi S, Stanley HR, Fitzgerald RJ. The effects of surgical expo-sures of dental pulps in germ-free and conventional laboratory rats. Oral Surg Oral Med Oral Pathol, 20: 340–9, 1965.

4. Siquieira JF Jr. Taxonomic changes of bacteria associated with endodontic infections. J Endod, 29: 619–23, 2003.

5. da Silva LA, Nelson-Filho P, Faria G, de Souza-Gugelmin MC, Ito IY. Bacterial profile in primary teeth with necrotic pulp and periapical lesions. Braz Dent J, 17: 144–8, 2006.

6. Reddy S, Ramakrishna Y. Evaluation of antimicrobial efficacy of vari-ous root canal filling material used in primary teeth: microbiological study. J Clin Pediatr Dent, 31: 1995–9, 2007.

7. Peters LB, Wesselink PR, van Winkelhoff AJ. Combinations of bacter-ial species in endodontic infections. Int Endod J, 35: 698–702, 2002.

8. Siqueira JF Jr, Jung IY, Rôças IN, Lee CY. Differences in prevalence of selected bacterial species in primary endodontic infections from two distinct geographic locations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 99: 641–7, 2005.

9. Baumgartner JC, Siqueira JF Jr, Xia T, Róças IN. Geographical differ-ences in bacteria detected in endodontic infections using polymerase chain reaction. J Endod, 30: 141–4, 2004.

10. Baumgartner CJ. Microbiological and molecular analysis of endodon-tic infections. Endod Top, 7: 35–51, 2004.

11. Carlsson J, Sundqvist G. Evaluation of methods of transport and culti-vation of bacterial specimens from infected dental root canals. Oral Surg Oral Med Oral Pathol, 49: 451–4, 1980.

12. Ng YL, Spratt D, Sriskantharajah S, Gulabivala K. Evaluation of proto-cols for field decontamination before bacterial sampling of root canals for contemporary microbiology techniques. J Endod, 29: 317–20, 2003.

13. Manzur A, González AM, Pozos A, Silva-Herzog D, Friedman S. Bac-terial quantification in teeth with apical periodontitis related to instru-mentation and different intracanal medications: a randomized clinical trial. J Endod, 33: 114–8, 2007.

14. Siqueira JF Jr, Rôças IN. Catonella morbid and Granulicatella adian-cens: new species in endodontic infections. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 102: 259–64, 2006.

15. Cox ST Jr, Hembree JH Jr, McKnight JP. The bactericidal potential of various endodontic materials for primary teeth. Oral Surg Oral Med Oral Pathol, 45: 947–54, 1978.

16. Khemaleelakul S, Baumgartner JC, Pruksakorn S. Identification of bacteria in acute endodontic infections and their antimicrobial suscep-tibility. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 94: 746–55, 2002.

17. Picard C, Fioramonti J, Francois A, Robinson T, Neant F, Matuchansky C. Review article: bifidobacteria as probiotic agents—physiological effects and clinical benefits. Aliment Pharmacol Ther, 22: 495–512, 2005.

18. Hojo K, Nagaoka S, Murata S, Taketomo N, Ohshima T, Maeda N. Reduction of vitamin K concentration by salivary Bifidobacterium strains and their possible nutritional competition with Porphyromonas gingivalis. J Appl Microbiol, 103: 1969–74, 2007.

19. Hojo K, Mizoguchi C, Taketomo N, Ohshima T, Gomi K, Arai T, Maeda N. Distribution of salivary Lactobacillus and Bifidobacterium species in periodontal health and disease. Biosci Biotechnol Biochem, 71: 152–7, 2007.

20. Orrhage K, Nord CE. Bifidobacteria and lactobacilli in human health. Drugs Exp Clin Res, 26: 95–111, 2000.

21. Whiley RA, Beighton D, Winstanley TG, Fraser HY, Hardie JM. Strep-tococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus (the Streptococcus milleri group): association with different body sites and clinical infections. J Clin Microbiol, 30: 243–4, 1992.

22. Chavez de Paz L. Gram-positive organisms in endodontic infections. Endodontic Topics, 9: 79–96, 2004.

23. Adib V, Spratt D, Ng YL, Gulabivala K. Cultivable microbial flora asso-ciated with persistent periapical disease and coronal leakage after root canal treatment: a preliminary study. Int Endod J, 37: 542–51, 2004.

24. Cannon RD, Chaffin WL. Oral colonization by Candida albicans. Crit Rev Oral Biol Med, 10: 359–83, 1999.

25. Schenkein HA, Burmeister JA, Koertge TE, Brooks CN, Best AM, Moore LV, Moore WE. The influence of race and gender on periodon-tal microflora. J Periodontol, 64: 292–6, 1993.

26. Sirinian G, Shimizu T, Sugar C, Slots J, Chen C. Periodontopathic bac-teria in young healthy subjects of different ethnic backgrounds in Los Angeles. J Periodontol, 73: 283–8, 2002.

27. Sundqvist G. Ecology of the root canal flora. J Endod, 18: 427–30, 1992.