冷热循环对纳米填料树脂与牙本质粘接界面的影响

Influence of Thermocycling on the Interface between Nanofilled Composite and Dentin

目的:探讨冷热循环对纳米填料树脂与牙本质粘接界面密合度的影响。方法:选完整离体人磨牙60颗随机均分3组,备邻洞后,用3M公司粘接剂(Adper Prompt)与该公司的光固化复合体F2000 Compomer(FT)、混合填料树脂FiltekTM Z250(ZT)和纳米树脂FiltekTM Supreme(FS)分别进行粘接充填,各组样本一半经2000次冷热循环(5℃和55℃),冷热循环组和非冷热循环组均经染料渗透实验,在体视显微镜下观测染料渗入界面的深度并用扫描电镜观察各组试件粘接界面的超微形态。结果:冷热循环前3种材料微渗漏深度差异无显著性(P>0.05),冷热循环后3种材料微渗漏深度差异有显著性(P<0.05),FS冷热循环测试前后的微渗漏深度差异有显著性,FT和ZT组冷热循环测试前后的微渗漏深度差异无显著性。扫描电镜下观察发现冷热循环可增大纳米树脂与粘接剂之间的裂隙。结论:冷热循环对纳米树脂与自酸蚀粘接剂的界面有负面影响。

Objective： To evaluate the influence of thermocycling on the interface between nanofilled composite and dentin. Methods： 60 extracted healthy molars were selected and divided into three groups randomly. Medial - occlusal cavities were prepared and then filled with light cured FiltekTM Supreme （ nanofilled composite）, F2000 Compomer （ small particle filled） and Filtek^TM Z250 （ microhybrid filled composite）, bonded with the same self - etch adhesive systems （ Adper prompt）. All samples were conditioned at 37 degrees for 24h. Half of the specimens of each group were thermocycled at 2000 cycles （at 5 and 55 degrees） with a dwell time of 60s. The thermocycled and non - thermocycled specimens were subjected to the dye penetration test. The bonding interfaces was evaluated under scanning electron microscope （SEM） Results： The microleakage of nanofilled composite significantly increased after thermocycling, as compared with the other two groups （P 〈 0.05）. And significant difference was found in FS group between prior to thermocycling and after thermocycling. The thermocycling increases the gap width between the nanocomposite and the self - etch adhesive systems under SEM observation. Conclusion： Thermocycling had negative effect on the interface of nanecomposite and the self - etch adhesive systems.