The Influence of Implant Design Features on Bone Healing Pathways: An Experimental Study in Sheep

The purpose of this study was to evaluate the influence of implant design features on osseointegration parameters. Two different implant macrogeometries and surface treatments were evaluated as follows: (1) progressive buttress threads possessing the SLActive surface (SLactive/BL), and (2) inner and outer trapezoidal threads possessing nano-hydroxyapatite coating over a dual acid-etched surface (Nano/U). Implants were placed in the right ilium of 12 sheep, and histologic/metric analyses were conducted after 12 weeks in vivo. The percentage of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within the threads were quantified. Histologic observations showed more intimate BIC in the SLactive/BL group compared to the Nano/U group. In contrast, the Nano/U group depicted woven bone formation generated between the wall of the osteotomy and implant threads within the healing chambers, while bone remodeling was evident at the tip of the outer thread. The SLActive/BL group presented higher BIC than the Nano/U group. On the other hand, significantly higher BAFO was observed at 12 weeks in the Nano/U group compared to the SLactive/BL group ( P < .042). Differences in implant design features influenced the osseointegration pathway, which supports the need for further investigations to describe the clinical performance and differences in a timely fashion. Int J Periodontics Restorative Dent 2022. doi: 10.11607/prd.5438