2014 Volume 55 Issue 7 Pages 1034-1039
Since the dental structure and the mechanical parameters of dental hard tissues would affect the propagation features of ultrasonic waves, laser ultrasonic nondestructive evaluation (NDE) technique can be used to assess human teeth. With the application of an expansion Laguerre polynomial technique, surface acoustic waves (SAW) in human incisors are calculated, and the effects of inhomogeneous elastic properties of enamel and initial dental caries on SAW are also discussed. An experimental setup to generate and detect SAW in incisor by noncontact and nondestructive manner is established. A focused laser line source is used to generate broadband SAW, which is detected by laser Dopple vibrometer on healthy incisor and initial dental carious, respectively. The results demonstrate that some dental parameters such as dental structures and initial dental carious can affect the phase velocities of laser induced SAW. Laser ultrasonic NDE methods have the potential for evaluation of human teeth in vivo.