Materials and Methods: Subgingival plaque samples were collected from 60 individuals with varying severity of chronic periodontitis and 30 individuals with a clinically healthy periodontium. The samples were subjected to PCR analysis to identify P. gingivalis, followed by heteroduplex analysis to identify the strain diversity in a given sample. Bacterial culture was carried out as a comparative standard.
Results: Of the 56 samples that were positive for P. gingivalis by PCR, 54 samples yielded eight different heteroduplex patterns. Analysis of these patterns indicated that two strains of P. gingivalis were present in 41 individuals (45.6%) and three strains were present in 13 individuals (14.4%). Detection of P. gingivalis by PCR was significantly more in the periodontitis group as compared to the healthy group.
Conclusions: Species-specific PCR and heteroduplex analysis provide a simple and accurate method to analyse the strain diversity of P. gingivalis. P. gingivalis was detected in both healthy periodontal sites as well as sites with periodontitis. The presence of two or three P. gingivalis strains was seen in 60% of the samples.
METHODS: Twenty patients with periodontitis were recruited for the trial. Following random allocation of either quadrants of the selected jaw to test or control treatment, conventional non-surgical periodontal therapy (NSPT) was performed. In addition, the test side received adjunct photodynamic therapy. Probing depth (PD), clinical attachment level, bleeding on probing (BoP) and plaque scores (PS%) were recorded at phase 0 (baseline), phase 1 (immediately after NSPT), phase 2 (7 days following NSPT), phase 3 (1 month following NSPT) and phase 4 (3 months following NSPT). Subgingival plaque samples for quantification of Aa by real-time polymerase chain reaction was performed at phases 0, 1, 2 and 4.
RESULTS: There was a significant clinical improvement at phases 3 and 4 compared with baseline while BoP reduced significantly only in the test group at phase 4. However, no difference in the quantification of Aa was detected between the groups.
CONCLUSIONS: Within the limits of the study, PDT adjunct to scaling and root planing does not lead to quantitative reduction of Aa in periodontitis patients.