Microbial Profile and Endotoxin Levels in Primary Periodontal Lesions with Secondary Endodontic Involvement.

This study was carried out to investigate the microbial profile and endotoxin levels of endodontic-periodontal lesions of periodontal origin. Periodontal and endodontic samples were taken from periodontal pockets and necrotic root canals of 10 teeth with endodontic-periodontal lesions. Evidencing of 40 different bacterial species were determined in each endodontic and periodontal sample using the checkerboard DNA-DNA hybridization method and Kinetic chromogenic LAL assay was used for quantification of endotoxins. Fisher's exact test correlated the bacterial species with the endodontic or periodontal microbiota. The endotoxin levels (EU/mL) found in samples of the root canal and periodontal pocket were compared by the Wilcoxon test (p<0.05). Bacteria and LPS units were found in 100% of the endodontic and periodontal samples. The species E. faecium, P. acnes, G. morbillorum, C. sputigena and L. buccalis were strongly correlated with the endodontic microbiota and P. nigrescens with the periodontal microbiota. P. intermedia, P. endodontalis and V. parvula were more prevalent in both endodontic and periodontal microbiots. The endotoxin levels in the periodontal pocket (89600 EU/mL) were significantly higher than in the root canal (2310 EU/mL). It was concluded that the microbiota present in the periodontal and endodontic tissues is similar, with a higher prevalence of species of the orange complex and a higher level of endotoxin in the periodontal pockets.