Ultrasound as a Tool to Measure the Wear of Human Tooth Enamel

A reliable tool for assessing the extent of human enamel wear would be useful to dental practitioners. Current in-vivo methods for determining tooth wear are largely qualitative in nature or depend on measurements taken from tooth impressions, which is very time consuming. The aim of this work was to investigate the feasibility of using ultrasound to measure enamel thickness with a view to developing an in-vivo tool for enamel wear assessment. Three different ultrasonic techniques were used in-vitro to take measurements of enamel on extracted teeth. The first used a focusing immersion transducer (25 MHz) and a time of flight approach to obtain enamel thickness. The other two techniques used planar contact probes (10 MHz), the first with a time of flight approach and the second with a resonance method to determine enamel thickness. The results were compared with direct measurements of sectioned teeth. All three methods showed good correlation with these measurements. The contact probe technique was the easiest measurement to carry out, which would also be the simplest to implement in a measurement tool. While the resonance measurements obtained were good, the time of flight approach was thought to be most likely to obtain accurate repeatable measurements.