IN-VITRO AND IN-VIVO MEASUREMENT OF REMAINING DENTIN THICKNESS

Experiments were performed in vitro on extracted human teeth and in vi vo on dog teeth to determine the accuracy of a pulse-echo mode with an ultrasonic micrometer in measuring remaining dentin thickness. The ac curacy of the ultrasonic micrometer measured remaining dentin thicknes s was compared with direct caliper measurements in measuring human den tin discs (correlation coefficient, r = 0.99). After modification of t he delay line tip (focusing tip), the device was found to be highly ac curate on both prepared extracted human teeth (r = 0.87) and in vivo o n dog teeth (r = 0.92). The use of ultrasonic technology to measure re maining dentin thickness looks promising. Further research needs to be performed to make the device more clinically useful.