Investigate the correlation between clinical sign and symptoms and the presence of P. gingivalis, T. denticola, and T. forsythia individually or as a “Red complex” by a multiplex PCR method

AIM: The aim of this study was to investigate the correlation between endodontic clinical signs and symptoms and the presence of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia or their association by Multiplex polymerase chain reaction assay. MATERIALS AND METHODS: Microbial samples were taken from 30 cases with necrotic pulp tissues in primary infections. DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens by using species-specific primers. RESULTS: P. gingivalis, T. denticola, T. forsythia, and Red Complex were present in 11, 17, 4, and 2 canals, respectively. Clinical and statistically significant relationships were found between T. forsythia and mobility and between T. denticola and swelling. (P < 0.05). Presence of other Red complex bacteria shows clinical association with presence of signs and symptoms but no statistically significant relationship. CONCLUSION: The high prevalence of P. gingivalis, T. denticola, and T. forsythia in the examined samples suggests that these bacteria are related to the etiology of symptomatic periradicular diseases.