Biomedical subjects

P T Sunde

Publications and source records attributed to P T Sunde.

2 recordsLinked to original sources

PubMed2000

Extraradicular infection: a methodological study.

Whether bacteria live or die in periapical lesions of endodontic origin is debated. Sampling of periapical bacteria is difficult due to possible contamination from the indigenous microflora. The aim of this study was to examine whether bacteria were present in periapical lesions of asymptomatic teeth before sampling or were transferred there during sampling. Thirty patients with root-filled teeth and periapical radiolucencies were divided into two groups, each containing 15 patients. In Group 1, a marginal incision was made to explore the periapical lesion. In Group 2, a submarginal incision was made. Before incision, the gingiva and mucosa were washed with 0.2% chlorhexidine gluconate. Bacterial samples were taken from the mucosa before reflecting the flap, and from the alveolar bone and the periapical lesion immediately after. All samples were cultured anaerobically on all-purpose and selective media. In Group 1, 12 of the 15 patients (80%) yielded bacteria from their mucosal samples despite the chlorhexidine wash. Bacterial growth was observed in all samples (100%) from the alveolar bone while the periapical lesions gave bacterial growth in 11 of 15 cases (73%). In Group 2, bacteria were cultured from the mucosa in 11 of 15 (73%) patients. Three samples (20%) from the alveolar bone and 10 from the periapical lesions (67%) gave positive growth. The predominant cultivable bacteria were anaerobic. Phenotypic profiling, performed with the data-based API bioMérieux system, indicated that the sampling technique used prevented mucosal bacteria from reaching the exposed bone and the periapical lesions. Profiling also indicated that following marginal incision, bacteria from the periodontal pocket might have reached the underlying tissues by surgeon-released bacteremia or direct translocation. Most organisms detected in the periapical lesions were clearly different from the bacteria present at neighboring sites and appeared to have been there before sampling.

Bacteria, Anaerobic↗

PubMed2000

Assessment of periradicular microbiota by DNA-DNA hybridization.

In the present study the "checkerboard" DNA-DNA hybridization technique was used to identify bacteria in periapical endodontic lesions of asymptomatic teeth. Thirty-four patients with root-filled teeth and apical periodontitis were divided into two groups, each containing 17 patients. In Group 1, a marginal incision was performed during surgery to expose the lesion, and in Group 2, a submarginal incision was applied. The gingiva and mucosa were swabbed with an 0.2% chlorhexidine gluconate solution prior to surgery. Bacterial DNA was identified in all samples from the two groups using 40 different whole genomic probes. The mean number (+/- SD) of species detected was 33.7 +/- 3.3 in Group 1 and 21.3 +/- 6.3 in Group 2 (P < 0.001). The majority of the probe-detected bacteria were present in more lesions from Group 1 than from Group 2. The differences were most notable for Campylobacter gracilis, Porphyromonas endodontalis, Propionibacterium acnes, Capnocytophaga gingivalis, Fusobacterium nucleatum ssp. nucleatum, Fusobacterium nucleatum ssp. polymorphum, Prevotella intermedia, Treponema denticola, Streptococcus constellatus and Actinomyces naeslundii I. Bacterial species such as Actinobacillus actinomycetemcomitans and Bacteroides forsythus were detected in more than 60% of the lesions from both groups. Also, P. endodontalis was abundant in periapical tissue. The data supported the idea that following a marginal incision, bacteria from the periodontal pocket might reach the underlying tissues by surgeon-released bacteremia. The study provided solid evidence that bacteria invade the periapical tissue of asymptomatic teeth with apical periodontitis. The detection of much more bacteria with the "checkerboard" DNA-DNA hybridization method than has previously been recovered by anaerobic culture indicated that the endodontic (and periodontal) microfloras should be redefined using molecular methods.

Actinomyces↗