【摘要】 目的:评价Er,Cr:YSGG激光备洞对离体牙楔形缺损处非龋性硬化牙本质与复合树脂间粘结性能的影响。方法:选取40个颊侧颈部有楔形缺损的老年人(60~70岁)前磨牙,随机分2组(n=20),分别用Er,Cr:YSGG激光(实验组)和高速涡轮牙钻(对照组)备洞后,用复合树脂Filtek Z350进行充填;然后每组各取15个样本制备成粘结面积约为1 mm×1 mm的哑铃形片状试件,用Instron 5848微力试验机测定其微拉伸粘结强度(MBS);每组剩余的另5个样本分别沿颊舌向平行于牙体长轴分成两部分后,用扫描电镜观察粘结界面形态。结果:实验组和对照组的MBS(MPa)分别为35.24±7.05和27.56±4.79(P<0.05);扫描电镜下可见,实验组混合层较薄,部分区域的混合层、树脂突及牙本质小管内的硬化结晶柱紧密连接在一起。结论:Er,Cr:YSGG激光预备有助于提高老年人非龋性硬化牙本质与复合树脂材料间的粘结强度。更多还原

【Abstract】 AIM: To evaluate the effect of Er,Cr: YSGG laser preparation on the bonding properties between composite resin and the the sclerotic dentin of elderly subjects. METHODS: 40 extracted premolars with cervical wedge-shaped defect and sclerotic dentin on the surface from 60 ~ 70 year-old people were randomly divided into 2groups( n = 20). In the experimental group Er,Cr: YSGG laser was used for cavity preparation,in the control group regular burs with high-speed turbines was used for cavity preparation. The cavies of all teeth were filled with composite resin Filtek Z350. 15 samples in each group were cut into dumbbell-shaped specimens with a bonding area of 1 mm2.The micro-tensile bond strength( MBS) was tested on Instron 5848 Micro Tester. Each tooth of the remaining 5 samples in each groupe were divided into two parts along buccolingual directions parallel to the long axis of the tooth. The bonding interface was observed by SEM. RESULTS: The MBS( MPa) of experimental and control groups was( 35.24 ±7.05) MPa and( 27.56 ±4.79) MPa respectively( P <0.05). SEM observation showed that hybrid layer between sclerotic dentin and composite resin was thinner in experimental group,resin tags,and crystallizing column within dentinal tubules connected together tightly. CONCLUSION: Er,Cr: YSGG laser preparation can improve the bond strength between elderly non-carious sclerotic dentin and composite resin.更多还原