Effect of aerobic and anaerobic atmosphere on acid production from sorbitol in suspensions of dental plaque and oral streptococci.

Abstract

The pH changes and the amounts of the metabolic end products lactate, formate, acetate and ethanol were studied in suspensions of dental plaque material. The suspensions were incubated with sorbitol or glucose for 30–80 min, in the presence or absence of air. The acid production activity from neither sorbitol nor glucose was affected by the exposure of the plaque suspensions to air. The differences in the concentrations of the four metabolic end products between the suspensions challenged with sorbitol in the presence and absence of air were small. Only traces of lactate were formed from sorbitol both in the aerobic and anaerobic atmosphere. The amounts of formate and ethanol were greater in the suspensions incubated with sorbitol than with glucose. The pH changes were also studied in suspensions of anaerobically grown strains of Streptococcus mutans, Streptococcus sanguis and Streptococcus mitior, challenged with sorbitol or glucose for 30 min. The pH decreased considerably less in the suspensions incubated with sorbitol in the presence of air compared to those kept anaerobically. The pH drop from glucose was, however, the same irrespective of the atmosphere conditions.