Periodontal microbiota and clinical periodontal status in a rural sample in southern Thailand

Abstract

We sought to determine (i) the association of subgingival bacterial profiles to clinical periodontal status in a population with limited access to dental care in Thailand, and (ii) the external validity of our earlier findings from a similar study in rural China. We examined 356 subjects, 30–39 yr old and 50–59 yr old, with respect to clinical periodontal status and subgingival plaque at maximally 14 sites per subject. Checkerboard hybridizations were used to analyse a total of 4343 samples. The prevalence of the 27 species investigated ranged between 87.2% and 100%. Discriminant analysis based on microbial profiles classified correctly 67.5% of all deep (≥ 5 mm) and 64.2% of all shallow sites, and 67.4% of all subjects with and 69.3% of all subjects without ≥ 3 deep pockets. High colonization by ‘red complex’ bacteria was four times as likely (95% Confidence Limits (CL) 2.5–6.6) in subjects with ≥ 10 sites with attachment loss of ≥ 5 mm, and 4.3 times as likely (95% CL 2.6–7.1) in subjects with ≥ 30 such sites. The data confirmed (i) the ubiquitous prevalence of the bacteria investigated in subjects with no regular access to dental care; and (ii) the high odds for periodontal pathology conferred by increased levels of specific periodontal bacteria.