Acoustic Impedance Measurement of Radiotherapy-Induced Effect on the Human Tooth by 320 MHz Scanning Acoustic Microscopy

摘要

Radiogenic dental damage is a common and crucial problem in patients receiving radiotherapy for malignancies inthe head and neck region. Unfortunately, little is known about the development of complications after radiationtherapy on the microstructure profiles of the human tooth. Therefore, we propose a novel method in which theprimary focus is to investigate, in vitro, the direct influences of different radiation doses on elastic propertiesof enamel and dentin of human tooth by Scanning Acoustic Microscopy (SAM) at the microscale. We obtaintwo-dimensional (2D) acoustic impedance images from twenty-five sound human third molars each of which iscut into a 1 mm thick cross-sectional slices. Acoustic impedance by SAM operating at 320 MHz are recordedfrom the sections comprising enamel and dentin before and after every irradiation dose to a cumulative doseof 60 Gy. The findings of our study reveal that radiation therapy changes the micro-elastic features of enameland dentin accompanied by the decreased acoustic impedance. We establish a relationship between cumulativeirradiation doses and the measured acoustic impedance. The quantified acoustic impedance values for thedifferent irradiation doses might be helpful in in vitro assays for the determination of the safe dose limits toprevent severe tooth damage in the treatment plan of the individuals having head and neck cancer.