Evaluation of bonding strength and bioactivity of zirconia implant material coated with different bioceramics

Pure titanium and titanium alloy implant systems in use today are regarded as the gold standard. However, due to some of the drawbacks of titanium implants, zirconia implant systems have became popular recently. In order to reduce the healing time and to increase the percentage of bone-implant contact, many studies have been aimed at improving the surface properties in zirconia implants as well as in titanium implants. The purpose of our study is to evaluate the bonding strength and bioactivity of zirconia implant materials coated with hydroxyapatite (HA) and wollastonite (W) powder at different ratios with plasma spraying technique. The bonding strentgth between zirconia and the coating was measured in accordance with ASTM C-633 standard. The data obtained were evaluated using one-way analysis of variance. Differences between groups were determined by Post Hoc Tukey HSD test. The samples prepared for the bioactivity test are incubated in 37 oC simulated body fluid (SBF) for 2, 7, 14, and 21 day periods. The changes that occur on surfaces of the sample were analized with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS) and x-ray diffraction instrument (XRD). The bonding strength evaluation revealed that W incorporation in different amounts resulted in significantly higher bonding strength to zirconia surface than pure HA coating. All sample groups used in this study showed bioactive propertis in SBF. Key words: Zirconia implant, plasma spray, wollastonite, hydroxyapatite, bioactivity, simulated body fluid, SBF.