Clinico-bacteriological study on dental calculus

Abstract

With a view to analyzing bacterial flora of dental calculus and examining its relationship with oral infections and bacteremia, bacterial isolation from dental calculus was performed and susceptibitity of these isolates to antibiotics was examined. On the basis of the experimental results with bacterial isolation method, bacterial isolation from dental calculus was performed by 48 hr-enrichment culture of sample in Tamai-Fukuda (TF) medium.
The results of bacterial examination of 203 cases of dental calculus revealed that only aerobes were isolated in 21 cases and both aerobes and anaerobes in the remaining 182 cases. A total of 741 isolates were obtained ; the number of aerobes and anaerobes were 393 (53.0%) and 348 (47.0 %), respectively. Bacterial genera isolated with high frequency were Lactobacillus (123 strains), Streptococcus (77 strains), Corynebacterium (57 strains), Staphylococcus (34 strains) in aerobes, and Veillonella (72 strains), Eubacterium (59 strains), Bacteroides (57 strains), and Peptococcus (50 strains) in the anaerobes; these bacterial general represented more than 70 % of all isolates, suggesting that they are main bacteria in the dental calculus. A total of 735 strains, 386 aerobes and 349 anaerobes, were tested, by three concentration-disc method, for susceptibility to 8 antibiotics, penicillin G (PCG), ampicillin (ABPC), cephaloridine (CER), tetracycline (TC), erythromycin (EM), clindamycin (CLDM), gentamicin (GM), and polymixin (PL). More than 90 % of strains of the aerobes and more than 95 % of those of the anaerobes were susceptible to CER, TC and CLDM, and to PCG, ABPC, CER, TC and CLDM, respetively.