Pathogenic potential of Enterococcus faecalis strains isolated from root canals after unsuccessful endodontic treatment.

Objectives: To evaluate strains of Enterococcus faecalis isolated from endodontic failures cases for (a) presence of virulence genes, namely, gelatinase production (gelE), surface protein (esp), collagen-binding adhesin (ace), cytolysin activator (cylA), E. faecalis antigen A (efaA) and aggregation substance (asa), all by using PCR; (b) biofilm formation capacity; and (c) activity of gelatinase and β-lactamase.

Materials And Methods: Twenty-five strains of E.

Microbiological Investigation in Teeth with Persistent/Secondary Endodontic Infection in Different Stages of Root Canal Retreatment.

Objective: The present clinical study investigated the microbiota of teeth with persistent secondary endodontic infection in the different phases of root canal retreatment.

Methods: Twenty filled single-rooted teeth with apical periodontitis were included. Samples were collected with sterile paper points before chemo-mechanical preparation (CMP) (S1), after CMP (S2) and after 30 days of calcium hydroxide-based intracanal medication (ICM) (S3).

Detection of Streptococcus mutans in symptomatic and asymptomatic infected root canals.

Objectives: To investigate the presence of Streptococcus mutans in root canals of symptomatic necrotic teeth (SNT) and their associated acute apical abscesses (AAA) and in the root canals of asymptomatic necrotic teeth (ANT). It also aimed to investigate the presence of the cnm and cbm genes in specimens that harbored S. mutans.