喷砂结合化学处理对软衬材料粘结效果的影响

Effect of surface pretreatments with sandblasting and chemical etchants on bond strength between a silicone-based resilient liner and denture base resin

目的:研究喷砂结合化学处理对硅橡胶软衬材料与基托树脂间粘结强度及基托树脂挠曲强度的影响。方法:制备48块30 mm×10 mm×7.5 mm热凝聚甲基丙烯酸甲酯树脂块,每2个树脂块配成一个试件,24个试件随机分为4组,每组6个试件,即:(1)喷砂组:喷嘴与试件轻接触,采用250μm的氧化铝,在0.62 MPa压力下喷砂30 s;(2)喷砂+丙酮组:粘结面喷砂处理同前,喷砂后的粘结面浸泡在丙酮溶液中30 s;(3)喷砂+甲基丙烯酸甲酯单体组(后简称单体):粘结面喷砂处理同上,喷砂后的树脂块粘结面浸泡在甲基丙烯酸甲酯溶液中180 s;(4)对照组:表面不处理。每个试件的两树脂块间衬以3 mm厚的软衬材料,冷热循环5 000次后,置于万能测试机上,以5 mm/min的加载速度测试其拉伸粘结强度。另制备24块65 mm×10 mm×3.3 mm长方体树脂块,分组及表面处理同前,涂布软衬材料粘结剂后测试挠曲强度。结果:喷砂组、喷砂+丙酮组、喷砂+甲基丙烯酸甲酯组及对照组试件的拉伸粘结强度分别为(1.31±0.45)MPa、(1.75±0.34)MPa、(1.96±0.50)MPa及(0.90±0.17)MPa。喷砂组与对照组间差别无统计学意义(P>0.05)。喷砂+丙酮组及喷砂+单体组的拉伸粘结强度与对照组相比有统计学差异(P<0.05);喷砂+丙酮组与喷砂+单体组组间比较无统计学差异;四组间挠曲强度均无统计学差异(P>0.05)。结论:喷砂结合化学处理树脂表面能增强硅橡胶软衬材料与基托树脂间的粘结强度,且对基托树脂挠曲强度没有影响。

Objective：To evaluate the effects of denture base resin surface pretreatments with sandblasting and chemical etchants in bond strength between a silicone-based resilient liner and denture base resin and the flexural strength of denture base resin. Methods： A total of 48 PMMA resin blocks （30 mm × 10 mm× 7.5 mm） were prepared and randomly divided into 4 groups： sandblasting; sand- blasting ＋ acetone; sandblasting ＋ monomer and control group （ no treatment）. A 3 mm silicone-based denture liner was applied be- tween every two blocks. After 5000 thermal eyelings, tensile bond strength was measured with a universal testing machine, at a crosshead speed of 5 mm/min. Another 24 PMMA resin specimens （65 mm × 10 mm × 3.3 mm） were prepared for flexural strength test,and trea- ted as before. After an adhesive was applied,the flexural strength was measured with a universal testing machine. Results：The tensile bond strength of sandblasting, sandblasting ＋ acetone, sandblasting ＋ monomer groups was （ 1.31 ±0.45 ） MPa, （ 1.75 ± 0. 34 ） MPa, and （ 1.96± 0. 50） MPa repectively, higher than that of control group （0.90± 0. 17 ） MPa. There was no statistically significant difference between group sandblasting ＋ acetone and group sandblasting ＋ monomer in the bonding strength （ P 〉 0.05 ）. Compared with the control group, there was statistical difference between group sandblasting ＋ acetone and sandblasting ＋ monomer in tensile bond strength（ P 〈0. 05 ）. Four experiment groups exhibited no statistical difference in flexural strength change. Conclusions ： All three surface pretreatments increased the tensile bond strength between a silicone-based resilient liner and denture base resin, and did not make the flexural strength of denture base resine decline.