RB was divided into 500-μm-wide horizontal zones (from BD to A) following the long axis of the implant. For each of these individual zones, BIC and bone density (B.Ar/T.Ar) were determined. Osteocyte and empty osteocytic lacunae were counted along the region of interest (ROI) (i.e., the area encompassing the intra-thread regions along the buccal RB extension) (Fig. 1) using a software program (Image J, software, 1.52a, Maryland, USA). Osteocyte density and empty lacunae density were determined by calculating the ratio of the number of osteocytes or empty lacunae in the region of interest.

The statistical analysis was performed using a commercially available software program (SPSS, 19.0, Chicago, IL, USA). Mean values, standard deviations, and confidence intervals for each variable were calculated at the implant level.