Effect of Streptococcus mutans and Streptococcus sobrinus strains on different carbo-hydrates with emphasis on dental caries - in vitro study

Abstract

The formation of bacterial plaque and acids in vitro by S. mu- tans and S. sobrinus, individually and in association, using different sugars as sucrose, glucose, fruc- tose and glucose + fructose was evaluated. The sucrose substrate showed superior statistical values in relation to bacterial plaque for- mation when compared to other analysed carbo-hydrates. The S. mutans species, individually and the association S. mutans / S. so- brinus, showed superior statistical amount of bacterial plaque in vitro when cultivated in environment added of 10% of sucrose. The spe- cies S. mutans and S. sobrinus, individually and in association, did not show a homogeneous behavior for acid production, showing dif- ferent moments of pH, decreasing along the incubation period. Key words: S. mutans, S. sobrinus, carbo-hydrate, dental caries.