Effect of experimental hyposalivation on the induction of dental caries in rats infected with Streptococcus mutans

The effects of hyposalivation on the induction of dental caries were examined in specific pathogen-free Sprague-Dawley rats infected with Streptococcus mutans MT8148R and fed the caries-inducing diet 2000. Hyposalivation was induced by either irradiation or surgical removal of salivary glands in 30-day-old rats. After either procedure, severe dental caries was induced in the rats when examined at 84 days of age, and a statistically significant correlation was found between caries scores and flow rates of saliva. However, the recovery of strain MT8148R from hyposalivated rats was not always high, and it is possible that microorganisms other than the inoculated S. mutans strain MT8148R may have played a role in promoting dental caries.