Abstract
Nanoindentation test results, reveled mechanical properties that are directly related to the local structure of the tooth. In this study, nano-hardness and nano-elastic modulus of human molar teeth were studied across the dentin-enamel junction (DEJ). Specimens were obtained from seven molar permanent teeth. Nano-hardness and nano-elastic modulus both decreased towards the DEJ. It is found that the nano-mechanical property profiles across the DEJ were due to a continuous variation in the ratios of relative amount of enamel and dentin. This result suggests that the DEJ displays a gradient in structure and that nanoindentation method show promise for further understanding its structure and function.
