唾液污染对复合树脂间粘接强度的影响

目的:了解不同种类的甲基丙烯酸酯复合树脂间的粘接效果以及唾液污染界面后对其粘接强度的影响.方法:选用AP-X和P60两种不同种类的甲基丙烯酸复合树脂,用SE-Bond自酸蚀粘接系统进行粘接.将AP-X树脂固化后打磨表面,根据界面处理方式不同分为3个实验组:直接粘接组、唾液污染组和唾液污染后75％乙醇擦拭组.对照组为在固化的AP-X树脂表面即刻分层充填、光固化P60树脂后形成的整块树脂材料.将上述树脂块切成数条1 mm×1 mm×14mm的试样,每组选取15条在扫描电镜下观察试样侧面两种树脂的粘接界面,另取15条测定其微拉伸强度,采用单因素方差分析法进行统计学分析.结果:扫描电镜观察可见:对照组整块树脂材料AP-X与P60紧密地嵌合在一起;3个实验组中,直接粘接组的两种树脂AP-X与P60紧密结合无缝隙,唾液污染组中的两种树脂粘接面存在明显的缝隙和陷窝,唾液污染后经75％乙醇擦拭后两种树脂的粘接面仍有大量间隙存在.各组复合树脂试样微拉伸强度分别为:对照组(84.07±1.57) MPa;实验组中3个亚组:直接粘接组为(76.08±2.42) MPa,唾液污染组为(70.98±2.33) MPa,75％乙醇擦拭污染组为(71.08±2.33) MPa,其中,对照组与实验组差异有统计学意义(P＜0.001);直接粘接组的拉伸强度明显高于唾液污染组和污染后75％乙醇擦拭组,差异有统计学意义(P＜0.001);唾液污染组和污染后75％乙醇擦拭组之间差异无统计学意义(P =0.893).结论:不同种类的甲基丙烯酸复合树脂不但可以结合,而且可获得较大的内聚强度;树脂界面打磨后仍可粘接,但微拉伸强度有所降低;唾液污染粘接界面明显降低复合树脂间的粘接强度,75％乙醇擦拭并不能消除其影响.

Effects of saliva contamination on bond strength of resin-resin interfaces

Objective:To estimate the bond strength between different resin composite interfaces,and to evaluate the effect of saliva contamination and management with the contamination on the bond strength.Methods:Two commercial resin composites containing different types of fillers (AP-X:barium-glass;P60:quartz) were tested in this study.The basic composite blocks were made of AP-X.After wet-ground flatted,the experimental groups were divided into three groups according to the surface treatment:(1)Direct bonding group:the bonding surface was rinsed with distilled water for 20 s,then dried with oil-free air for 20 s;(2) Saliva contamination group:the bonding surface was bathed in saliva for 30 min,then distilled water was rinsed for 20 s and dried with oil-free air for 20 s;(3) Saliva contamination and 75％ ethanol wiping group:bonding surface bathed in saliva for 30 min,then wipe the surface with 75％ ethanol,distilled water rinse for 20 s and dry with oil-free air for 20 s;The control group was made of the basic composite bulks of AP-X directly bonding with composite P60.Cut each resin block into 1 mm × 1 mm × 14 mm sticks,observing the micro-structures and detecting the microtensile strength of the resin composite interfaces.The bonding strength was measured using micro-tensile tester,then calculated and statistically analyzed by one-way ANOVA.Results:Scanning electronic microscope observation revealed that the control group as well as the direct bonding subgroups,two different resin tags were in good contact with each other.The saliva contamination subgroups had lots of gaps or craters,indicating saliva might have been trapped in the composite buildup and wiping the surface with 75 ％ ethanol had no effect.The micro-tensile bond strength of the control group was (84.07 ± 1.57) MPa and significantly higher than all the other 3 experimental subgroups(P ＜0.001).In experimental groups,the micro-tensile strength of 3 subgroups was (76.08 ± 2.42) MPa,(70.98 ± 2.33) MPa and (71.08 ± 2.33) MPa,respectively.The saliva contamination subgroup was significant lower than the direct bonding subgroup(P ＜ O.001),but no statistical significance with the ethanol wiping subgroup (P =0.893).Conclusion:The bond strength of inner polymerization of resin-resin was greater,but decreased after resin composites interfacial bonding.Saliva contamination reduced the tensile bond strength between resin composites surface,wiping the surface with 75％ ethanol had no effect.