Effects of chlorhexidine gluconate in drinking water on dental caries and oral microorganisms in the Syrian hamster.

Hamsters infected with Streptococcus sobrinus (formerly Streptococcus mutans) strain 6715-1119 were given high-sucrose diet 2000. After 5 days, they were presented with 0.05 or 0.1 per cent w/v chlorhexidine gluconate (CHX) continuously in their drinking water, which was well-tolerated. Compared to infected but untreated controls, their caries scores were less by 84 and 97 per cent respectively after 42 days. Coronal dental plaque deposits were reduced in a dose-related fashion. Culture plates of oral swabs showed reductions in Strep. sobrinus and total streptococci after 10 and 35 days of CHX. Hamster oral streptococci were more sensitive to CHX than were lactobacilli but neither was completely eliminated. The incidence of stained tooth deposits after 0.1 per cent CHX was slightly but not significantly greater than in controls.