The cariogenicity of frequent topical applications of water, sucrose, xylitol, sorbitol and sorbose was compared in a 20-day animal study under controlled feeding conditions. Osborne-Mendel rats were orally superinfected with Streptococcus mutans OMZ 176 and Actinomyces viscosus Ny 1 and received 25 daily ‘meals’of 0.4 g of diet 2000a containing 56%sucrose. Two topical applications were administered after each group of 5 programmed meals. The treatments significantly affected the fissure caries incidence. The highest scores were observed in the sucrose and sorbitol group. The number of fissure lesions in the xylitol and sorbose group did not significantly exceed that in the water gr