Colonization of the oral cavity by group mutans Streptococci according to age assesed by a semi-quantitative method in saliva Colonización de la cavidad oral por Streptococcus grupo mutans, según edad, evaluado en saliva por un método semi-cuantitativo

Abstract

Objective: To evaluate the colonization of group mutans streptococci according to age, measuring the amount of bacteria in saliva with a semi-quantitative method in a population attended in public and private dental centers of the Metropolitan Region, Santiago, Chile. Patients and Methods: Saliva samples were obtained from 14,649 patients aged 5 to 40 years, in one public and 5 private dental centers. Bacteria concentration was estimated by the comparison with a standard counting-chart. The concentration of group mutans streptococci in saliva was test by a 3-way ANOVA. Results: Bacterial concentration of Streptococcus mutans related with the age of patients was significant (p < 0.001). Bacterial concentration in the preschool age was 4,7 × 105 CFU/mL at 5 years, while 6,0 × 105 CFU/mL at 12 years of age, with a decrease in patients over 30 years. Bacterial concentration was significantly different in the six centers of the study. Conclusions: The semi-quantitative method was useful to