Evaluation of Bone Density for Primary Implant Stability Using a Newly Designed Drill: An In Vitro Study on Polyurethane Bone Blocks

Bone density is an important factor for long-term implant success. Peri-implant bone density evaluation before implant placement can be useful for treatment planning, such as the selection of proper implant size or drilling protocol in each case. In this study, we aimed to establish an objective intraoperative bone density evaluation method by measuring the drilling torque value using a newly designed density measurement drill. Drilling torque value measurement was performed intraoperatively using three types of drills; two previously reported drills and a newly designed drill as a density measurement drill. Polyurethane bone blocks of different densities (D1-D4) were used in this experiment. After the measurement, implants were inserted based on the scheduled plan, and insertion torque (IT) and implant stability quotient (ISQ) were measured to assess primary implant stability. The drilling torque value increased with the bone blocks' density, and there were significant differences among different densities in all groups (p