Evaluation of implant screw loosening by resonance frequency analysis with triaxial piezoelectric pick-up: in vitro model and in vivo animal study

摘要

Objective The aim of this study was to evaluate implant screw loosening using resonance frequency (RF) analysis with triaxial piezoelectric pick-up in vitro and in vivo. Methods For the in vitro experiment, a titanium implant was inserted into a mandibular model. The abutment screws were tightened to 10?N torque and loosened from 0 to 90° for RF measurement using 13 different screw conditions. In the in vivo experiment, three titanium implants were installed in each tibia of a New Zealand white rabbit, and the RF values were recorded after 8?weeks. For the RF analyses, a small 3D accelerometer was mounted rigidly onto the implant abutment, and impulsive vibration was directly applied to the abutment to vibrate the implant in a direction perpendicular to the tibia and implant ( x -axis). The y -axis was defined as parallel to the tibia. The RF values of the x - and y -axis directions (RF-X and RF-Y) were used for evaluation. Results The RF values significantly decreased according to the degree of screw loosening ( p ?