Dark-field microscopy of subgingival plaque microflora in Indian and English subjects

This present investigation reports on the microbial pattern of subgingival plaque from English and Indian subjects living in the West Midlands of England. Subgingival plaque from healthy and diseased sites was studied using darkfield microscopy. The results indicate that significant differences exist in microbial flora of clinically normal and diseased sites of English as well as Indian subjects. Coccoid cells predominated in healthy sites, with an increase of 21% in the spirochaetes in diseased sites. The ratio of non-motiles to motiles was 1:0.6 in healthy sites, whereas in diseased sites the ratio observed was 1:1.8 in English subjects and 1:3.6 in Indian subjects. Comparison of healthy sites in Indians with healthy sites in English subjects revealed significant differences between numbers of rods (p less than 0.05). Comparing diseased sites of Indians with diseased sites in English subjects revealed significant difference between both cocci (p less than 0.05) and motile rods (p less than 0.01). A positive correlation between chronic inflammatory periodontal disease and spirochaete burden, and a negative one between the disease and coccal burden, was found.