In-vivo study of ultrafine-grained CP-Ti dental implants surface modified by SLActive with excellent wettability

Abstract

This study investigates the simultaneous effect of substrate nanostructuring by severe plastic deformation and surface modification by SLActive on surface characteristics of CP-Ti grade 2 and evaluates the biocompatibility of it for use as implant material by in-vivo test. SLActive surface modification method is a modified SLA process that includes sandblasting, acid-etching, and cleaning by N2 in a vacuum chamber. To this end, the structure CP-Ti grade 2 was refined by applying the equal channel angular pressing (ECAP) method. Surface morphology, roughness, and wettability of coarse-grained (CG) and ultrafine-grained (UFG) CP-Ti and Ti-6Al-4V were determined after SLActive. It was seen that after surface modification of the samples by SLActive, the excellent wettability with a drop contact angle of about 0° was achieved for SLActived specimens. For the in-vivo test, the implants of each three groups were embedded in the femur of white New Zealand rabbits. In order to assess the osseointegration of implants, histological analysis, and pull-out tests were conducted. Results showed suitable osseointegration between implant and bone for every three groups, but the value of removal torque was higher for UFG-Ti. As is realized UFG-Ti sample surface modified by SLActive could be a suitable choice among the candidates to be used as a material in the manufacturing of dental implants.