Ex Vivo and In Vivo Biomechanical Test of Implant Attachment to Various Materials: Introduction of a New User-Friendly Removal Torque Equipment

Abstract

The removal torque (RTQ) analysis is commonly used for biomechanical evaluation of osseointegration. The overall aim of this study was to verify results obtained with a newly developed equipment for biomechanical testing of osseointegration. Verification of the new equipment for biomechanical tests involved three experiments: Part I, comparison of RTQ between implants placed in four different types of dental synthetic plasters. Part II, comparison of RTQ between custom made, experimentally used implants to self-tapping, commercially available implants molded in the same type of dental plaster. Part III, comparison of RTQ between commercially pure titanium implants to Ti6Al4V implants placed in rabbit bone, 6 weeks after insertion. Briefly, for all experiments, the peak RTQ values and the removal process were recorded every 0.01 seconds up to 10 seconds. After the measurements, peak RTQ values were converted to shear strength. The developed equipment sensitively responded to the changes of properties related to the molding plasters, implant topographies, and materials. The monitored graphs corresponded well to the expected properties of the different implants and tested materials. The new RTQ equipment proved to be accurate and could add new knowledge in understanding the biomechanical aspects of osseointegration.