Identification of the mechanisms governing modifications of the wettability characteristics of a magnesia partially stabilized zirconia bioceramic following CO₂ laser treatment

The mechanisms responsible for modifying the wettability characteristics of a magnesia partially stabilized zirconia (MgO-PSZ) bioceramic material after CO₂ laser treatment have been elucidated. Changes in the contact angle, θ, which characterizes the wettability characteristics of the MgO-PSZ, were attributed primarily to: modifications to the surface roughness of the material, the incorporation of oxygen at the surface, and the increase in the polar component of the surface energy, γ_sv^p. However, the degree of influence exerted by each mechanism was found to differ markedly. Isolation of each of these mechanisms permitted the magnitude of their influence to be qualitatively determined. Surface energy, by way of microstructural changes, was found to be by far the most predominant element governing the wetting characteristics of the MgO-PSZ. To a much lesser extent, incorporation of oxygen at surface, was also seen to influence the change in the wettability characteristics of the MgO-PSZ, while surface roughness was found to play a minor role in inducing changes in the wettability characteristics.