Mandibular Bone Structure Analysis Using Cone Beam Computed Tomography vs Primary Implant Stability: An Ex Vivo Study

To evaluate the relationship between mandibular bone structure parameters measured on preimplant cone beam computed tomography (CBCT) images and primary implant stability.

Twenty-one hemimandibles were scanned on the 3D Accuitomo 170 CBCT. Next, an implant was placed in each hemimandible, after which insertion torque and implant stability quotient (ISQ) measurements were acquired. The following measurements were performed on the preimplant CBCT scans: bone surface, bone volume, fractal dimension, connectivity, trabecular thickness and spacing, and skeleton analysis. Measurements were performed using various regions of interest in the vicinity of the implant site. In addition, cortical thickness was measured. The correlation between bone structure parameters, insertion torque, and ISQ was calculated.

The overall correlation was low to medium (|R| = 0.002-0.723). For the bone around the entire implant site, the highest correlation with ISQ was found for skeleton analysis and trabecular thickness. The highest overall correlation between bone structure and ISQ was found in the coronal region. For insertion torque, no significant correlation was found for the bone around the entire implant; the highest overall correlation was found in the apical region. The highest number of significant correlations between bone structure and primary implant stability were found for trabecular thickness and fractal dimension.

While each of the investigated bone structure parameters can have a predictive value in terms of primary implant stability, they should be measured at specific regions surrounding a planned implant site, and can provide complementary information regarding the local bone quality.