Correlation between Bone Density Classified by Computed Tomography (CT) Value and Trabecular Bone Structure: A Study on Bovine Bone

Bone density is an important parameter for successful dental implant treatment. As a preoperative evaluation before implant placement, computed tomography (CT) scan is performed to determine bone volume and density. The Misch bone density classification is based on two criteria: (1) tactile sensation during implant site drilling and (2) CT value expressed in Hounsfield units (HU). The classification categories gradually decrease in HU, from D1 (>1250 HU) to D5 (<150 HU). In experimental studies, bovine bone has been used to investigate primary stability, implant geometry, and surgical techniques. However, a detailed study on the correlation between bone density and trabecular bone structure has not been reported in bovine bone. This study aimed to verify the correlation between bone density classification by CT value and the trabecular bone structure on bovine bone. Fifteen sites of D2-D5 from bovine bones were selected using multidetector CT scan. Histological evaluation was performed, and the bone area ratio, expressed as a percentage of the bone area within the region of interest, was calculated. The bone area ratio differed significantly between each pair of Misch classification (p < 0.05), except for D3 and D4. The CT value and bone area ratio showed a significant positive correlation (r = 0.92, p < 0.05). This result suggests that the evaluation of bone density by CT value is related to its histological structure.