Teeth mobility measurement by laser Doppler vibrometer

In this work a new procedure for the assessment of teeth mobility, based on a noncontact sensor (laser Doppler vibrometer), is presented. The procedure is based on the manual application of impulses applied with an instrumented hammer on the tooth crown. The ratio of the maximum displacement of the tooth to the peak of the input force has been considered as the mobility degree index. A basic mechanical model of the hammer-tooth impact based on the data extracted from literature has been realized. Results produced with the model mentioned above have been compared with those measured with in vitro and in vivo tests using the proposed procedure. Good agreement between data from the mechanical model and in vitro conditions has been found. Tests carried out in in vitro and in vivo conditions have demonstrated the validity of the procedure proposed. Measurement results compared to those found in the relevant literature show the validity of the procedure proposed. (C) 1999 American Institute of Physics. [S0034-6748(99)04706-1].