[Influence of surface conditions on the results of Periotest value. An in vitro and in vivo study].

In several experiments it was examined, whether slight deviations from the using reglementation for the PERIOTEST-device alter the measurement results. Tilting of the handpiece against ground or variation of the distance between handpiece and the surface of the tooth within the suggested intervals did not alter the PERIOTEST-value. If the measurement was done more incisal then specified, the PERIOTEST-value increased, if the measurement was done more cervical, the value decreased. Tilting the handpiece against the tooth surface within +/- 8 degrees in horizontal and +/- 6 degrees in vertical direction gave only little effect on the PERIOTEST-value on clinical firm upper front teeth.