Histomorphologic and bone-to-implant contact evaluation of dual acid-etched and bioceramic grit-blasted implant surfaces: an experimental study in dogs.

The objective of this study was to histologically evaluate a bioceramic grit-blasted and acid-etched surface (presenting calcium and phosphorous incorporation within the surface and its oxide) versus a dual acid-etched (no calcium and phosphorous, control) moderately rough implant surface in a dog tibia model.
Implants 3 x 10 mm were placed bilaterally along the proximal tibia of 6 Doberman dogs and remained for 2 and 4 weeks in vivo. After the dogs were euthanized, the implants were nondecalcified processed to approximately 30-microm-thick plates. Transmitted light optical microscopy was used to evaluate healing patterns and bone-to-implant contact. Statistical analysis was performed by 1-way analysis of variance at the 95% level of significance and by Tukey post hoc tests.
At 2 weeks, histologic evaluation showed woven bone formation throughout the perimeter of both implant surfaces. However, replacement of woven bone by lamellar bone was only observed around the test surface at 4 weeks in vivo. No significant differences in bone-to-implant contact were observed for the different groups (P > .27).
Despite nonsignificant differences between bone-to-implant contact for the different surfaces and times in vivo, higher degrees of bone organization were observed for the test implants. Biomechanical testing is warranted to verify potential differences in biomechanical fixation effectiveness between surfaces.