Local tissue effects and peri-implant bone healing induced by implant surface treatment: an in vivo study in the sheep.

Abstract

The aim of this study was to assess, through biological analysis, the local effects and osseointegration of dental implants incorporating surface micro/nanofeatures compared with implants of identical design without surface treatment. Known to impact bone cell behavior, surface chemical and topography modifications target improved osseointegration and long-term success of dental implants. Very few studies assess the performance of implants presenting both micro- and nanofeatures in vivo on the animal models used in preclinical studies for medical device certification. Implant surfaces were characterized in terms of topography and surface chemical composition. After 4weeks and 13weeks of implantation in sheep femoral condyles, forty implants were evaluated through micro-computed tomography, histopathologic, and histomorphometric analyses. No local adverse effects were observed around implants. Histomorphometric analyses showed significantly higher bone-to-implant contact in the coronal region of the surface-treated implant at week 4 and week 13, respectively, was 79.3±11.2% and 86.4±6.7%, compared with the untreated implants (68.3±8.8% and 74.8±13%). Micro-computed tomography analyses revealed that healing patterns differed between coronal and apical regions, with higher coronal bone-to-implant contact at week 13. Histopathologic results showed, at week 13, bone healing around the surface-treated implant with undistinguishable defect margins, while the untreated implant still presented bone condensation and traces of the initial drill defect. Our results suggest that the surface-treated implant not only shows no deleterious effects on local tissues but also promotes faster bone healing around the implant.