Treatment outcome of surgical and non-surgical endodontic retreatment of teeth with apical periodontitis.

Aims: To evaluate and compare the treatment outcome of root filled teeth with apical periodontitis treated either non-surgically or by endodontic microsurgery, and to assess the influence of an intra-radicular post, clinical and demographic factors.

Methodology: Clinical and radiological data from 1157 patients with apical periodontitis in previously root filled teeth treated by postgraduate students at the Department of Endodontics, University of Oslo, between September 2010 and January 2020 with recall data at least 11 months from completion were studied. Surgical cases were scored using the Rud/Molven criteria and grouped into success, uncertain or failure at control.

Extended-spectrum beta-lactamase-producing bacteria are not detected in supragingival plaque samples from human fecal carriers of ESBL-producing Enterobacteriaceae.

Background: The prevalence of infections caused by Cefotaximase-Munich (CTX-M)-type extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) has rapidly increased during the past 15 years. Enterobacteriaceae are commonly found in the gastrointestinal tract and long-term intestinal carriage is considered important for the spread of ESBL and as a source of clinical infections. Oral biofilm such as supragingival plaque is known to contain numerous antibiotic resistance determinants and may also represent a poorly investigated site for ESBL carriage and further spread.

High prevalence of β-lactam and macrolide resistance genes in human oral Capnocytophaga species.

Objectives: To determine macrolide-lincosamide-streptogramin (MLS) resistance determinants in the Capnocytophaga genus and to describe the prevalence of β-lactam resistance genes in human oral Capnocytophaga species.

Methods: Forty-eight Capnocytophaga isolates identified by analysis of 16S rRNA sequences were isolated from subgingival samples from 14 haematology patients (HPs), 11 periodontitis patients (PPs) and 17 healthy volunteers (HVs). MICs of β-lactam and MLS antibiotics were obtained for all isolates.

Bacterial diversity in persistent periapical lesions on root-filled teeth.

Background: The purpose of this study was to analyze the bacterial diversity in persistent apical lesions on root-filled teeth by using culture-independent molecular methods.

Design: Twenty surgically removed apical lesions from therapy-resistant teeth were examined for the presence of bacterial DNA using PCR targeting the 16s ribosomal RNA gene, followed by cloning and sequencing.

Results: Bacterial DNA was detected in 17 of the 20 samples (85%).

Chromosome- and plasmid-encoded beta-lactamases in Capnocytophaga spp.

Chromosome- and plasmid-encoded CfxA2 and CfxA3 beta-lactamases were detected in Capnocytophaga spp. from oral sources in France, Norway, and the United States. Unidentified chromosome-encoded beta-lactamases were present in Capnocytophaga sputigena.

Detection and characterization of beta-lactamase genes in subgingival bacteria from patients with refractory periodontitis.

Fifty-three beta-lactamase-producing strains of oral bacteria isolated from patients with refractory periodontitis in Norway and USA were screened for the presence of the bla(TEM), bla(SHV), bla(OXA), bla(ampC), bla(cfxA), and bla(cepA/cblA) genes by the polymerase chain reaction (PCR). The PCR products were characterized by direct sequencing of the amplified DNA. Thirty-four of the 53 enzyme-producing strains (64%) were positive in one of the PCR assays.

Antibiotic resistance in bacteria isolated from subgingival plaque in a norwegian population with refractory marginal periodontitis.

The prevalence of beta-lactamase-producing bacteria in subgingival plaque from patients with refractory periodontitis in Norway was assessed by the chromogenic nitrocefin method. beta-Lactamase activity was detected in 68% of the patients. Enzyme-producing strains belonged predominantly to the genus Prevotella; others were staphylococci, enteric gram-negative rods, and Bacillus spp.