The mechanisms responsible for modifications to the wettability characteristics of an SiO2/Al2O3–based ceramic material in terms of a test–liquid set, comprising human blood, human blood plasma, glycerol and 4–octonol, after high–power diode–laser (HPDL) treatment, have been elucidated. Changes in the contact angle, θ, and hence the wettability characteristics of the SiO2/Al2O3–based ceramic, were attributed primarily to modifications to the surface roughness of the ceramic resulting from HPDL interaction, which accordingly effected reductions in θ, and to the increase in the surface oxygen content of the ceramic after HPDL treatment, since an increase in surface oxygen content intrinsically brings about a decrease in θ (and vice versa) and the increase in the polar component of the surface energy, γPsv, due to the HPDL–induced surface melting and resolidification, which consequently created a partly vitrified microstructure that was seen to augment the wetting action. 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 determined qualitatively. Surface energy, by way of microstructural changes, was found to be by far the most predominant element governing the wetting characteristics of the SiO2/Al2O3–based ceramic. To a much lesser extent, surface oxygen content, by way of process gas, was also seen to influence changes in the wettability characteristics of the SiO2/Al2O3–based ceramic, while surface roughness was found to play a minor role in inducing changes in the wettability characteristics.