In four separate studies, 50% aqueous solutions of sugar substitutes (150 or 200 μl) were topically applied 3 or 5 times daily on molar teeth in rats receiving a low cariogenic diet (20% sucrose) ad libitum. All animals had been inoculated with Actinomyces viscosus Ny 1, Streptococcus mutans OMZ 176 and feces from caries-active rats. No diarrhea was observed and reduced weight gains were found in only one study. The topical application of sugar substitutes was noncariogenic. However, no sugar substitute significantly and consistently reduced bacterial agglomerate (rat plaque) formation, smooth surface or fissure caries incidence versus the water controls