[Comparative studies of the hardness of dental calculus after the use of 2 dentifrices].

A method was described for recording the mechanical characteristics of tartar using objectively comparable test data. This method was used to study tartar which had formed when different tooth pastes were used. The results of this study indicate that 1. Tartar formed when different tooth pastes are used may exhibit different characteristics; 2. The dynamic measurement of indentation is suitable for quantitative determination of the mechanical characteristics of tartar. These mechanical characteristics have not been ascertainable until now.