The role of surface modification on zirconia implants to enhance osteoblasts adhesion and proliferation

Abstract

The surface structure of the implant plays a crucial role in the success of implantation. Therefore, the surfaces of dental implants have been under continuous development over the past few decades. In zirconia implants, generating surface roughness by sandblasting may induce surface damage and phase transformation from tetragonal to monoclinic phase. To avoid these negative effects, sandblasting prior to sintering is one strategy to generate a rough zirconia surface.

The aim of this study was to investigate the influence of surface roughening zirconia base material, TZP, by sandblasting prior to sintering process under defined parameters. The new surface structure was then examined in vitro on the basis of cellular adhesion (after 60 min with crystal violet), cell coverage (after 72 h with crystal violet), proliferation and metabolic activity (24-48 h with BrdU assay and after 48 h with XTT assay, respectively) of human SAOS-2 osteoblasts.

Using a Perthometer, the roughened zirconia variants exhibited negligible changes in surface roughness before and after sintering, and they maintained their original mechanical properties by avoiding post-treatment of the surfaces. Initial cell adhesion was positively enhanced by a roughened surface compared to a machined surface. The metabolic activity and proliferation in the log-growth phase were not affected. Surface coverage by cells was slightly decreased on rough zirconia surfaces compared to the machined reference; however, surface coverage on all zirconia surfaces was comparable to that of titanium, indicating good biocompatibility. Therefore, the method used to roughen the zirconia surface in this experiment is suitable for zirconia implants, which is an alternative implant material.

Sandblasting before sintering zirconia implants is an appropriate method to create surface roughness without compromising the mechanical strength.