目的: 探究两种玷污层去除方法对牙本质表面性能的影响。方法: 选取60颗健康无龋第三磨牙，制备牙本质玷污层实验试件，随机分为3组：对照组、超声(ultrasonic treatment, UT)组、酸蚀(etched treatment，ET)组。采用扫描电镜观察各组的表面微观形貌，通过能量色散X射线光谱仪、X射线衍射仪、傅里叶变换红外光谱仪分别对表面元素、矿物相及官能团作分析，并进一步评价牙本质的机械性能、亲水性以及生物相容性。结果: 扫描电镜下UT组和ET组可见清晰的牙本质小管结构，对照组牙本质小管结构不清晰，可见大量牙本质碎屑；元素分析结果3组均可见钙磷峰，其中ET组的钙磷元素峰值最弱；矿物相分析表明3组均具有羟基磷灰石特征峰；官能团分析UT组和ET组可见胶原的酰胺Ⅰ、Ⅱ、Ⅲ带特征峰，而对照组酰胺带特征峰不明显；显微硬度显示ET组低于对照组以及UT组，差异有统计学意义(P＜0.05)；接触角实验证实ET组的亲水性优于对照组及UT组；荧光染色结果显示3组均具有良好的生物相容性。结论: UT和ET均可有效清除牙本质试件表面的玷污层，暴露出牙本质结构，且不影响其微观形貌和生物相容性，采用UT去除玷污层时对牙本质试件表面矿物质结构、亲水性和机械性能没有明显影响，ET虽能有效改善牙本质亲水性，但却会导致其表面钙磷含量下降，机械性能降低。

Objective: To explore the effects of two methods of smear layer removal on the surface properties of dentin. Methods: Sixty extracted sound third molars were collected in this study, and were prepared as uniform dentin specimens with smear layer. All specimens were randomly divided into three groups: Control group, ultrasonic treatment (UT) group and etched treatment (ET) group. Scanning electron microscope (SEM) were used to observe the surface micromorphology of all three groups. Then, the surface elements, mineral phases and functional groups were analyzed by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and flourier transformed infrared spectrometer (FTIR) respectively. The mechanical properties, hydrophilicity and biocompatibility were also further evaluated. Results: It was revealed that dentin tubules of UT and ET groups were exposed, but lots of dentin debris piled up on the surface of the control one which covered up dentin tubules on the surface. The EDX results should that the weaker peak value of calcium and phosphorus in ET group than control and UT groups. Characteristic peaks of hydroxyapatite could be seen by XRD in all of the three groups, but lower distinctive peaks of amide Ⅰ, Ⅱ and Ⅲ bands of collagen of the dentin surface in control group than in ET and UT groups. The microhardness results showed that ET group was lower than control and UT groups, the difference was significant (P < 0.05). Better hydrophilicity of ET group was investigated (P < 0.05) than control group and UT group. Cells could be observed to adhere normally to dentin surface of each group which meant that all of the three groups had good biocompatibility. Conclusion: Both UT and ET could effectively remove the smear layer on the surface of dentin and had no adverse effect of the dentin micromorphology and biocompatibility. The ultrasonic removal of the smear layer did not influence the mineral structure, hydrophilicity and mechanical properties of dentin surface. Although ET can effectively improve the hydrophilicity of dentin but decreased mechanical properties and the content of calcium and phosphorus.