ISOLATION OF ROOT CANAL PATHOGENS FROM PRIMARY ENDODONTIC INFECTION AND RETREATMENT CASES – A CLINICAL COMPARATIVE STUDY

Aim: The purpose of this study was to isolate and compare the prevalence of common root canal pathogens; Streptococcus mitis, Lactobacillus acidophilus and Enterococcus faecalis from primary endodontic infections and retreatment cases. Materials and method: 60 subjects scheduled for root canal treatment or retreatment were divided into two groups comprising of 30 subjects with primary endodontic infections and 30 subjects with failed endodontic treatment. Root canal samples were collected as per Moller's criteria using sterile paper point. Advanced microbiological culture techniques were used to isolate Streptococcus mitis, Enterococcus faecalis and Lactobacillus acidophilus from primary root canal infections and retreatment cases. Statistical analysis was done using Student's T test and Pearson's Chi-Square test. Results: A total of 50 cultivable isolates were recovered from 60 root canal samples. Among them 26 isolates were from primary infection and 24 isolates were from secondary infection. Streptococcus mitis(53.3%) was significantly more associated with primary infection. On the other hand Enterococcus faecalis (46.7%) was the most predominant microorganism in retreatment cases. Conclusion: Higher prevalence of Streptococcus mitis in primary infection and Enterococcus faecalis in secondary infection, suggest that specific type of root canal infection has an affinity to specific group of microorganisms. Knowledge regarding this association may be beneficial in adopting strategies to combat root canal infections for better prognosis. 1 2 3 4 Vineet R.V. , Moksha Nayak, Subbannayya Kotigadde, Beena Antony Senior Lecturer, Department of Conservative Dentistry & Endodontics, Sree Mookambika Institute of Dental Sciences, Kulasekharam, Principal & Professor, Department of Conservative Dentistry & Endodontics, KVG Dental College & Hospital, Sullia Professor, Department of Microbiology, K.V. G Medical College & Hospital, Sullia Professor, Department of Microbiology , Father Muller Medical College, Mangalore INTRODUCTION : Endodontic disease is the result of both the pathogenic effects of the microbes and the response of the host. The goal of clinicians is to disrupt and destroy the microbial ecosystem associated with the disease process. Understanding of microbial ecology of the pulp-dentine complex is important because it provides a rational basis for disease prevention and treatment. [1] Endodontic treatment involves treatment of both primary and secondary infections in the root canal system. Primary infections are caused by microorganisms that colonize the necrotic pulp tissue. It can be regarded as the initial or 'wild' infection and are the cause of primary apical periodontitis. [2] Clinical studies have reported a success rate of endodontic therapy ranging from 87% to 95%. [3] Secondary infections are caused by microorganisms that were not present in the primary infection, but were introduced in the root canal at some time after professional intervention[4]. The composition of the microflora of root canals differs in primary infection and retreatment cases of endodontic origin. [5] Microorganisms from dental caries have proved to be the most common causative factor of pulpal disease. Studies have shown that Streptococcus sp. , Lactobacillus sp. , Enterococcus sp. are strongly associated with dental caries. [6] A relatively wide range of bacteria have been isolated from root canals using standard culture techniques. However, only 50% of the bacteria in the oral cavity are cultivable. [7] Use of advanced anaerobic microbiological techniques and culturing in selective media have been proven to be beneficial in this regard. A selective medium contains antimicrobial agents that are capable of suppressing all other microorganisms other than one for which the medium is designed. Selective culturing constitutes an efficient technique to detect very low proportions of specific microorganism from a sample. [8] ISOLATION OF ROOT CANAL PATHOGENS FROM PRIMARY ENDODONTIC INFECTION AND RETREATMENT CASES – A CLINICAL COMPARATIVE STUDY.