CARIES AND PLAQUE INHIBITION IN RATS BY 5 TOPICALLY APPLIED DENTIFRICES

The effectiveness of 5 different brands of dentifrices on caries and p laque were tested in rats in 2 experiments. 10 litters of rats each we re infected with Streptococcus sobrinus OMZ-176 and Actinomyces viscos us Nyl. The rats were offered the diet 2000a containing either 40% of sucrose (study I) or 10% of sucrose (study II). The following products were tested topically: (1) H2O, (negative control); (2) chlorhexidine diacetate, (positive control); (3) Parodontax NF; (4) Meridol; (5) Co lgate Total; (6) Mentadent C; (7) Dent Xpress. Comparisons with the wa ter control in study I showed that plaque extent was decreased by chlo rhexidine diacetate, Dent Xpress and by Mentadent C only. All fluoride -containing dentifrices tested reduced caries. In study II, comparison s with the water control showed that plaque extent was reduced by chlo rhexidine diacetate, Parodontax, Meridol, Dent Xpress and by Mentadent C. All dentifrices reduced caries, however, the incidence was low. Th ese 2 studies confirm that fluorides incorporated in dentifrices decre ase dental caries in the rat. Differences in the effectiveness of cari es inhibition between the 5 dentifrices could not be explained either by the form of fluoride utilized or by the antimicrobials added. Rathe r, the performance of a given dentifrice depended upon the concerted a ction of the particular ingredients. It appears that the effect of ant iplaque agents should be evaluated in the rat model using a diet conta ining sucrose at a low level.