Assessment of Correlation Between Computerized Tomography Values of the Bone and Cutting Torque Values at Implant Placement: A Clinical Study

Purpose: The relationship between computerized tomography (CT) values of bone surrounding endosseous implants and the cutting torque values required for self-tapping during implant placement was examined for the purpose of predicting the initial stability (bone quality) during implant placement by presurgical CT scan examinations and determining whether it can be quantified. Materials and Methods: The study sample consisted of 13 subjects with 56 implants. Sites for implant placement were determined based on CT data using implant planning software. The average CT values of the bone surrounding the simulated implants were calculated by the software. Using a stereolithographic drill guide, implants were placed at the locations indicated by the protocol. The cutting torque values required for self-tapping were measured during implant placement. The resulting CT values and cutting torque values were analyzed statistically for correlation. Results: The correlation was considered significant at a level of .01 or less, and the correlation coefficient was 0.77. Discussion: There was a strong correlation between CT values and cutting torque values in the clinical cases evaluated. These results indicate that it may be possible to predict and quantify initial implant stability and bone quality from presurgical CT diagnosis and implant simulation. Conclusion: Presurgical CT examination may be an effective technique for predicting initial stability of the implant and bone quality.