After sintering and autoglazing, the surface free energy of seven different dental ceramic materials was determined by contact angle measurements, using a Dynamic Adsorption Tester and three different standard probe liquids, before and after in vitro corrosion and also before and after incubation with human whole saliva. The surface free energy was calculated from the Young-Dupre-equation and the polar and non-polar components were determined. The total surface free energy (range 50±5 mN/m) did not differ significantly between the different ceramic materials or between corroded and non-corroded specimens. The basic surface chemical character persisted after corrosion, although reduced to a lower level, which probably reflects ion exchange processes at the exposed surfaces. After saliva incubation the basic component of the surface free energy increased, which may be interpreted as the result of salivary proteins binding to the basic surface with their acidic groups, orienting their basic sites towards the bulk phase. Selective adsorption of proteins to biosurfaces will no doubt influence both microbiological colonisation and cell adhesion, although the exact mechanisms are not known.