In a method and apparatus for detecting a crack in a human tooth, especially one covered by a restoration, such as a crown, the approach is to stress the suspect tooth and, by means of acoustic emission techniques, analyze the characteristics of the resultant acoustic emission from the tooth. To aid the identification of a crack from the acoustic emission signal, a baseline may be obtained by performing this procedure at a time when the tooth is known not be cracked, e.g., when a restoration is placed on it. This baseline acoustic emission signature is recorded. This procedure is repeated at intervals. The subsequent measurements are compared with the baseline to identify changes that indicate the initiation and growth of a crack. The invention includes apparatus for implementing the method. The approach is to integrate the acoustic emission pulser and sensor into commercially available dental instruments, e.g., a tooth polisher and a water syringe.
