The aim of this paper was to elucidate the mechanisms behind salivary lubrication with special emphasis on the lubricity of three pellicle key components (human acidic proline-rich protein 1 (PRP-1), human statherin and bovine submaxillary mucin (BSM)). The lubricating properties of the proteins have been assessed by means of colloidal probe atomic force microscopy, and are discussed in relation to their adsorption behavior. To various extent, the investigated proteins all showed a lubricating effect when adsorbed to silica surfaces. For comparable concentrations, PRP-1 was found to have a more pronounced lubricating effect than BSM, which in turn showed a higher lubricity than statherin. The relative lubricity is in accordance with previously reported relative adsorbed amounts of the three proteins, within the investigated concentration interval. We conclude that PRP-1 has the highest lubricating capacity as a pure fraction among the investigated preparations, and that the lubricating effect of PRP-1 as a pure fraction is notably large as compared to the lubricity of human whole saliva