Effect of bone quality and quantity on the primary stability of dental implants in a simulated bicortical placement

Objectives Conventional dental implants inserted in the molar region of the maxilla will reach into the sinus maxillaris when alveolar ridge height is limited. When surgery is performed without prior augmentation of the sinus floor, primary stability of the implant is important for successful osseointegration. This study aimed at identifying the impact of bone quality and quantity at the implantation site on primary implant stability of a simulated bicortical placement. Materials and methods In our in vitro measurements, bone mineral density, total bone thickness and overall cortical bone thickness were assessed by micro-computed tomography (mu CT) of pig scapulae, which resembled well the bicortical situation found in human patients. Dental implants were inserted, and micromotion between bone and implant was measured while loading the implant with an axial torque. Results The main findings were that primary implant stability did not depend on total bone thickness but tended to increase with either increasing bone mineral density or overall cortical bone thickness.