Potential damage to bone-implant interface when measuring initial implant stability

Background: An electronically controlled mechanical tapping device (MTD) to measure implant stability has been studied extensively for its ability to measure initial stability at the time of surgical placement and predict an implant's survival prognosis, with few reported complications. Methods: Initial stability data, measured repeatedly with a resonance frequency analysis device and the MTD, MTD, for seven of 28 implants placed in jawbones of four fresh human cadavers and the histologic images of bone-implant interfaces are presented as evidence for potential damage to the bone- implant interface using these techniques. Results: A progressive increase in mobility from stable (-1) to less stable (4) and eventually to visibly mobile (999) was observed after three measurements with the MTD. Corresponding histologic images revealed that the buccal threads in the coronal half of the implants were displaced lingually and apically from the bony indentations that were created during insertion of the self-threading implants, subsequent to repeated MTD measurements in the buccal and axial directions. The histologic images and changes in MTD values indicated that repeated MTD measurements at the time of implant placement surgery may damage the bone-implant interface, and a stable or borderline implant may become mobile after repeated MTD measurements. Conclusions: Histologic images showed potential damage to the bone-implant interface during repeated initial implant-stability measurements using the MTD. Initial implant-stability measurements using the MTD should be performed with caution, and they may be contraindicated for implants placed in low-quality bone.