By using a reciprocating sliding wear test machine, wear behaviors of human tooth enamel opposite to titanium alloy were investigated under the lubrication of artificial saliva for different contact time. Wear mechanism of human tooth enamel was studied by means of various microscope examinations including laser confocal scanning microscopy （LCSM）, X-ray photoelectron spectroscope （XPS） and X-ray diffraction （XRD）. The results show that wear of human tooth enamel changes gradually from two-body wear into three-body wear with delamination occurring on the worn surface during the process. With the number of cycles increasing, wear rate decreases and finally the wear of enamel stays in a stable stage. In conclusion,wear of human tooth enamel is controlled by mechanical removal process. There is no evidence that tribochemical process occurs on the surface of enamel.
human tooth enamel