SURFACE ACOUSTIC WAVE PERIODONTAL PROBE AND METHOD OF DETECTING PERIODONTAL DISEASE
An ultrasonic probe (10) for measuring the depth of detachment between a tooth (30) and the tooth's supporting tissue includes a probe head (12) having an ultrasonic transducer (35). An incident acoustic wave pulse (50) is transmitted through a coupling medium at a critical angle of incidence for refraction at the interface between the coupling medium and the tooth surface (29, 31) to effect modal conversion to a surface acoustic wave pulse along the surface of the tooth (30). The critical angle of incidence is established by means of an angular setting of the ultrasonic transducer (35) in the probe head (12), a combination of the aforementioned angular setting with the ability to rock the probe head (12) to find the critical angle of incidence, and/or a phased array implementation. The disclosure also includes an algorithm for determining the depth of detachment based on the time lapse between transmission and detection of the reflection of the acoustic wave pulses.