Er,Cr:YSGG激光预备离体牙Ⅴ类洞对光固化复合树脂边缘微渗漏影响的研究

The effect of Er,Cr:YSGG laser irradiation on the microleakage of Class V resin composite restorations

目的研究比较Er,Cr:YSGG激光预备与传统牙钻预备离体牙Ⅴ类洞对光固化复合树脂边缘微渗漏的影响。方法于2007年3月至7月,在中国医科大学实验设备处和中国医科大学口腔医学院中心实验室,将30颗离体前磨牙随机分为3组制备Ⅴ类洞:牙钻预备加37%磷酸处理组,单纯激光预备组,激光预备加37%磷酸处理组,每组10颗牙。经冷热循环染色后,采用染料渗入和扫描电镜方法观察充填体微渗漏情况。结果壁及龈壁处,染料渗入结果显示,牙钻预备加37%磷酸处理组的染料渗入评分最小,与其他两组比较差异有统计学意义(P<0.05),而单纯激光预备组与激光加37%磷酸处理组之间差异无统计学意义。充填体边缘微缝隙宽度的结果显示,单纯激光预备组的边缘微缝隙宽度最大,与其他两组比较差异有统计学意义(P<0.05),而牙钻预备加37%磷酸处理组与激光预备加37%磷酸处理组之间差异无统计学意义。结论Er,Cr:YSGG激光预备处理Ⅴ类洞不能增加光固化复合树脂与牙体组织的结合,减少微渗漏的发生;而应用激光加37%磷酸可以取代传统牙钻加37%磷酸进行窝洞预备。Er,Cr:YSGG激光预备离体牙Ⅴ类洞对光固化复合树脂边缘微渗漏的影响研究还有待于继续进行。

Objective The purpose of this study was to compare and study microleakage of Class V resin composite restorations following high-speed rotary and Er,Cr:YSGG laser preparation using a total etch adhesive system.Methods From March 2007 to July,in the Equipment Office of China Medical University and the Laboratory Center of the Affiliated Stomatological Hospital of China Medical University,thirty premolar teeth were randomly divided into three groups with 10 teeth each,group 1:bur + 37%phosphoric acid;group 2:Er,Cr:YSGG laser;group 3:Er,Cr:YSGG + 37%phosphoric acid.After being prepared and filled,the specimens were subjected to thermocycling.Then the marginal microleakage were observed by dye penetration method and SEM.Results On either the occlusal walls or gingival walls,microleakage test revealed bur + 37%phosphoric acid etched cavities was significantly lower than that achieved after the two laser groups(P<0.05).No statistical differences were found between the two laser groups.The space between the restorations and tooth structure revealed that the laser group was wider than the other groups(P<0.05).There were no statistical differences between bur+ 37%phosphoric acid group and Er,Cr:YSGG + 37%phosphoric acid group.Conclusion Based on the results of the microleakage test,Laser irradiation of enamel or dentin is not a valid alternative to conventional preparation with acid etch for resin composite restorations.Conventional preparation with acid etch gave the lowest microleakage.But SEM revealed that Laser with acid etch provided an equivalent method of tooth removal compared to Conventional preparation with acid etch.