目的：研究类瓷树脂和两种玻璃陶瓷牙合贴面在咀嚼和温度疲劳后牙合接触区的磨耗程度及表面粗糙度的变化，优选对临床有指导意义的牙合贴面材料。方法：将24颗完整的离体人前磨牙预备成牙合面中重度磨耗的形态,轴壁釉质完整、牙尖斜度20°。制作1.5 mm厚的类瓷树脂、热压铸造二硅酸锂增强型玻璃陶瓷（热压铸瓷）、计算机辅助设计/计算机辅助制造（computeraided design/computer-aided manufacturing, CAD/CAM）切削二硅酸锂增强型玻璃陶瓷（CAD/CAM切削瓷）牙合贴面。使用树脂粘接剂将牙合贴面粘接到预备体牙合面形成试件，在水中储存 72 h后在咀嚼模拟疲劳机上进行模拟5年口内温度疲劳和咀嚼疲劳的实验（5~55 ℃冷热水循环，模拟后牙咀嚼循环120万次）。用三维激光模型扫描和数字化分析法评价疲劳实验前后牙合贴面的磨耗程度，用三维形貌测量激光显微镜观察其表面形态及粗糙度变化。使用单因素方差分析方法对结果进行统计学分析，以P<0.05为差异有统计学意义。结果：咀嚼和温度疲劳实验后没有试件发生脱粘接或折裂。类瓷树脂组、热压铸瓷组、CAD/CAM切削瓷组的平均磨耗为（-0.13±0.03） mm、（-0.05±0.01） mm和（-0.05±0.01） mm，类瓷树脂组的磨耗量显著大于玻璃陶瓷两组（P<0.001）；疲劳实验前各组牙合接触区的表面粗糙度（Ra）为(1.24±0.20) μm、（0.75±0.09） μm、（0.73±0.14） μm，类瓷树脂组的表面粗糙度显著高于玻璃陶瓷两组（P<0.001）；疲劳实验后的表面粗糙度为（1.81±0.24） μm、（1.53±0.26） μm及（1.77±0.23） μm，热压铸瓷组显著低于类瓷树脂组（P=0.005）及CAD/CAM切削瓷组（P=0.010）。结论:从磨耗速度来看，类瓷树脂牙合贴面显著高于两种玻璃陶瓷，但更接近于对颌牙为天然牙时牙釉质的平均磨耗速度；从表面粗糙度来看疲劳实验前类瓷树脂的表面粗糙度显著高于两种玻璃陶瓷，疲劳实验后热压铸瓷牙合贴面的表面粗糙度最低。

Objective：To evaluate the wear intensity and surface roughness of occlusal veneers on premolars made of microhybrid composite resin or two kinds of ceramics in vitro after the thermocycling and cyclic mechanical loading tests. Methods: In the study,24 fresh extracted human premolars without root canal treatment were prepared （cusps reduction of 1.5 mm in thickness to simulate middle to severe tooth wear, the inclinations of cusps were 20°）. The prepared teeth were restored with occlusal veneers made of three different materials: microhybrid composite, heatpressed lithium disilicate ceramic and computeraided design/computer-aided manufacturing (CAD/CAM) lithium disilicate ceramic in the thickness of 1.5 mm. The occlusal veneers were cemented with resin cement. The specimens were fatigued using the thermocycling and cyclic mechanical loading tests after being stored in water for 72 h. The wear of specimens was measured using gypsum replicas and 3D laser scanner before and after the thermocycling and cyclic mechanical loading tests and the mean lost distance (mm) was used to indicate the level of wear. The surfaces of occlusal contact area were observed and the surface roughness was recorded using 3D laser scanning confocal microscope before and after the fatigue test. Differences between the groups were compared using ONE-way ANOVA（P<0.05）. Results: All the specimens successfully survived after the thermocycling and cyclic mechanical loading tests. The mean wear of microhybrid composite group, heatpressed lithium disilicate ceramic group, and CAD/CAM lithium disilicate ceramic group was （-0.13±0.03） mm, （-0.05±0.01） mm and （-0.05±0.01） mm, the wear of microhybrid composite was significantly higher than the two ceramic groups（P<0.001）.The mean surface roughness（Ra）before the fatigue test was(1.24±0.20) μm, （0.75±0.09） μm, （0.73±0.14） μm and it became （1.81±0.24） μm, （1.53±0.26） μm and （1.77±0.23） μm after the test . Before the fatigue test, the surface roughness of microhybrid composite was significantly higher than the two ceramic groups（P<0.001） and after the test, the surface roughness of heat-pressed lithium disilicate ceramic was significantly lower than microhybrid composite（P=0.005） and CAD/CAM lithium disilicate ceramic(P=0.010). Conclusion: From the view of wear speed, microhybrid composite was significantly higher than the two kinds of ceramics, but it was similar to enamel when the opposing tooth was natural. The surface roughness before the themocycling and cyclic mechanical loading test of microhybrid composite was significantly higher than that of the two ceramic groups. After the test, the surface roughness of heat-pressed ceramic was significantly lower than that of the other two groups. From the view of surface roughness, heat-pressed ceramic has more advantage.