Comparative 3D micro-CT and 2D histomorphometry analysis of dental implant osseointegration in the maxilla of minipigs

Aim: The bone implant contact (BIC) has traditionally been evaluated with histological methods. Thereupon, strong correlations of two-dimensional (2D) BIC have been detected between μCT and destructive histology. However, due to the high intra-sample variability in BIC values, one histological slice is not sufficient to represent 3D BIC. Therefore, our aim has been to correlate the averaged values of 3-4 histological sections to 3D μCT.

Material and methods: Fifty-four implants inserted into the maxilla of 14 minipigs were evaluated. Two different time points were selected to assess the 3D BIC (distance to implant: 2-5 voxels), an inner ring (6-30 voxels) and an outer ring (55-100 voxels) using μCT (voxel size: 10 μm) and to correlate the values to histomorphometry.

Results: Strong correlations (p < 0.0001; 28 days, 56 days, total) were seen between μCT and histomorphometry concerning BIC (r = 0.84, r = 0.85, r = 0.83), the inner ring (r = 0.87, r = 0.87, r = 0.88) and the outer ring (r = 0.85, r = 0.85, r = 0.88). Closer to the implant, μCT values were higher compared with histomorphometry.

Conclusion: Although 3-4 histological slices per implant seem to predict the 3D BIC, μCT might be advantageous because of its non-destructive 3D character. The healing time may not impact on the comparability.