Bacterial Identification in Symptomatic and Asymptomatic Endodontic Infections by Culture Method

Abstract

The aim of this study was to investigate the microorganisms from of necrotic root canals and to study the associations between symptoms and certain bacterial species, using culture methods. Nineteen symptomatic and twenty-one asymptomatic cases, between 18 to 75 years, having primary endodontic infections, and adhering to the inclusion and exclusion criteria were selected for this study. The targeted microorganisms were Prevotella, Porphyromonas, A.actinimycetmcomitans. E.faecalis.. The organisms that were detected were, Porphyromonas gingivalis, Aggregatibactor actinomycetemcomitans , Prevotella and additional important bacteria like Streptococci, Fusobacterium nucleatum, Klebsiella Capnocytophaga were found by culture analysis, but microorganisms such as and E. faecalis could not be identified. No association was seen between symptoms and bacterial species detected. 1 . The goal of endodontic treatment is the eradication of these microbes. Current treatment protocols like isolation, canal preparation, antibacterial irrigants and intracanal medicaments, are directed towards bacterial elimination. The rationale for the development of treatment protocols are all based on data involving microbiological root canal sampling (MRS) as there is an intimate involvement of bacteria and clinical endodontics. Microbiological root canal sampling is the foundation of clinical endodontics. 2 The finding from microbiologic studies conducted at different parts of the globe reveal that a given species that is very prevalent in root canals of patients from some geographic regions is not necessarily found in similar figures or even detected in samples from other locations. 3 Studies have suggested that genetic and environmental factors can influence the composition of oral microbiota particularly with regard to the periodontal pathogens. 4,5 It is well known that most periodontal pathogens are also endodontic pathogens and as a consequence variations in their prevalence have a potential to exert a significant influence in the composition of the microbiota of infected root canals. Similar variations were seen in microflora of endodontic infections. 6 Endodontic infection can be symptomatic or asymptomatic and the factors responsible for the development of symptoms are not completely understood. Early studies attempted to correlate some bacterial species with symptoms, but it has been demonstrated that the same species can also be found in asymptomatic cases. It seems that the appearance of symptoms might be a result of a complex mechanism, depending on diverse pathogen related and host-related factors. Despite the availability of various molecular methods for the evaluation of microbes, culture analyses are not redundant. The advantage of cultivation approaches are related to their broad-range nature, which makes it possible to identify a great variety of microbial species in a sample, including those that are not being sought after. Cultivation makes it possible to study the physiological properties and pathogenicity of the microbes. There has been a significant focus recently on developing methods for the in-vitro cultivation of those species that were till recently refractory to culture. Use of dilute nutrient media, increasing the incubation time, modification of the culture media with addition of specific substrates, co-cultivation with helper strains, colony hybridization method, used in isolation or in combination have helped in the culturing of hitherto uncultivable microbes. 7 An effort has been made in this study to identify the microbes in symptomatic and asymptomatic primary endodontic infections in patients, by the culture method.