Abstract
Hardness and elasticity of enamel and dentin of healthy permanet teeth from 6 to 7 by Mohs were measured by means of Dulometer, and the results were summarized as follows. Difference in hardness in diffent parts of a tooth was readily perceived. The difference seems to be based upon the degree of thickess of tooth's hard tissue. In dentin, local hardness difference was smaller than in enamel, and the difference became smaller toward the posterior teeth, which was inverse in enamel. Elasticity of dentin is also higher in posterior teeth than in anterior teeth, and the individual diviations are greater than those in enamel.
