Polymicrobial etiology of dental caries.

ABSTRACT

The present study was carried out to establish the normal bacterial oral flora and the aerobic and anaerobic bacterial flora from deep seated dental caries, and to determine the antimicrobial sensitivity of the clinical isolates so obtained Streptococcus mutans (48%) and Streptococcus sanguis (20%) were the main aerobic isolates whereas Lactobacillus spp. (52%), Veillonella spp. (24%) and Actinomyces spp. (12%) were the major anaerobic isolates. Hundred percent of the samples from dental caries yielded polymicrobial isolates while in two samples from healthy individuals S. mutans was the sole isolate. As the flora changed from healthy tooth to dental caries it changed from one predominated by anaerobic gram-positive cocci to anaerobic gram-positive bacilli. All the anaerobes isolated were sensitive to metronidazole and cefotaxime, whereas all the isolated streptococci were sensitive to penicillin, erythromycin and clindamycin. Incorporation of the antibiotics in baseline restoration, if technically feasible, has been advocated.