Diversity of Enterococcus faecalis Genotypes from Multiple Oral Sites Associated with Endodontic Failure Using Repetitive Sequence-based Polymerase Chain Reaction and Arbitrarily Primed Polymerase Chain Reaction.

INTRODUCTION: The aim of this study was to evaluate the diversity and similarity of Enterococcus faecalis genotype isolates from multiple oral sites using repetitive sequence-based polymerase chain reaction and arbitrarily primed polymerase chain reaction (AP-PCR). METHODS: Forty-two endodontically treated teeth with apical periodontitis were selected. A total of 126 microbial samples were collected from 3 different sites (saliva, pulp chamber, and root canals, all n = 42) during the nonsurgical retreatment procedures. After growth on m-Enterococcus agar, the colonies were isolated, characterized as gram-positive catalase negative cocci, and identified using an API 20 Strep kit (bioMérieux, Marcy-l'Etoile, France). Seventy-four colonies from 10 patients were confirmed as E. faecalis by polymerase chain reaction (16S ribosomal RNA). Repetitive sequence-based polymerase chain reactions using ERIC and AP-PCR using RW3A primers were performed in all 74 colonies. Fingerprints were analyzed and separated into genotypic groups based on the Dice coefficient percentage of similarity (82% or greater) as determined by ERIC reproducibility assays involving E. faecalis controls. RESULTS: Seven different E. faecalis genotypes (GTs) (GT1 = 27%, GT2 = 17.6%, GT3 = 1.3%, GT4 = 18.9%, GT5 = 9.5%, GT6 = 14.9%, and GT7 = 10.8%) were observed in different subjects and oral sites associated with endodontic failure. Remarkably, in 4 of 5 patients, the same GTs present in the infected root canals were also isolated from either the pulp chamber or the saliva samples. In particular, GT6 was detected in all 3 oral sites of patient 37. CONCLUSIONS: E. faecalis GTs isolated from saliva, the pulp chamber, and the root canal were similar using the Rep-PCR and AP-PCR methods. These findings suggest that coronal microleakage is a conceivable cause of endodontic failure.

Treponema diversity in root canals with endodontic failure.

OBJECTIVE: This study sought to investigate the prevalence of eight oral Treponemas (Treponema denticola, T. amylovorum, T. maltophilum, T. medium, T. pectinovorum, T. socranskii, T. vicentii and T. lecithinolyticum) in teeth with endodontic treatment failure and periapical lesion. METHODS: Samples were taken from 40 root canals presenting endodontic failure and periapical lesion. DNA extraction was performed and Nested-PCR technique was used for the detection of Treponema species using specific primers. RESULTS: Treponemas was detected in 56.5% of the samples analyzed (22/39). Individual root canals yielded a maximum of 6 target Treponema species. T. denticola (30.8%) and T. maltophilum (30.8%) were the most frequently detected species followed by T. medium (20.5%), T. socranskii (20.5%), T. pectinovorum (17.9%) and T. vicentii (17.9%). Positive association was verified between T. denticola and T. maltophilum such as T. medium (P<.05). T. lecithinolyticum was positively associated with intraradicular post (P<.05). CONCLUSION: The present study revealed that a wide variety of Treponema species plays a role in persistent/secondary infection turning the root canal microbiota even more complex than previously described by endodontic literature.