Application of Terahertz Waves for Dental Treatment

The terahertz wave, which is expected to be used in the future medical field, was examined for the possibility of being applied to conservative pulp treatment. For example, in order to avoid pulpectomy in the deep caries treatment, it is extremely useful to detect the remaining amount of carious dentin and the distance to the pulp in the cavity. As a pilot study of application to dental treatment, the propagation velocity of terahertz waves in enamel and dentin was measured. As controls, natural single crystal of apatite and HIP-treated powder apatite were also measured. As a result, enamel and dentin had different propagation velocities. It suggests that not only enamel and dentin in the oral cavity but also sound dentin and carious dentin with different calcification degrees can be identified by terahertz waves because the propagation rate increases depending on the density of apatite in the sample.