A non-destructive method of evaluating the elastic properties of anterior restorative materials.

An ultrasonic pulse transit-time method was used to determine the Young's modulus, shear modulus, and Poisson's ratio of seven anterior-restorative materials. Small rectangular specimens were immersed in a water bath and ultrasonic pulses propagated through them. Two types of ultrasonic wave could be generated inside the specimen by altering the angle of incidence. Measurement of the pulse transit-time for these two waves enabled their velocities and, hence, the material's elastic constants to be calculated. The variation of these properties with time of conditioning and temperature was also determined.