Zhang Ying, Zhang Huai-qin, Ma Jun-chi, Jin Si-yuan
Institute of Stomatology, Nanjing Medical University & Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2011 Dec;46(12):762-4.
To evaluate the effect of denture base resin surface pretreatment with chemical etchants on microleakage and bond strength between silicone-based resilient liner and denture base resin. The initial bending strength of denture base resin after surface pretreatment was also examined.
Thirty-six polymethyl methacrylate (PMMA) denture base resin blocks (30 mm × 30 mm × 2 mm) were prepared and divided into three groups: group acetone, group methyl methy acrylate (MMA) and group control. Subsequently, a 2 mm silicone-based resilient liner was applied between every two blocks. After 5000 cycles in the thermal cycler (5 and 55°C), they were immersed in the (131) I solution for 24 hours and γ-ray counts were measured. Another 36 PMMA resin blocks (30 mm × 10 mm × 7.5 mm) were prepared. The blocks were divided into three groups and treated as mentioned above. A 3 mm silicone-based resilient liner was applied between every two blocks. After 5000 thermal cycles, tensile bond strength of the sample was measured in a universal testing machine. Another 18 PMMA resin blocks (65 mm × 10 mm × 3.3 mm) were prepared. They were divided into 3 groups and treated in the same way. After an adhesive was applied, the bending strength was measured with three-piont bending test.
Two experimental groups showed lower microleakage (520.0 ± 562.2 and 493.5 ± 447.9) and higher tensile bond strength [(1.5 ± 0.4) and (1.4 ± 0.5) MPa] than the group control [microleakage: (1369.5 ± 590.2); tensile bond strength: (0.9 ± 0.2) MPa, P < 0.05]. There was no statistically significant difference between group acetone and MMA in microleakage and tensile bond strength (P > 0.05). There was no statistically significant difference in bending strength among the three groups (P > 0.05).
Treating the denture base resin surface with acetone and MMA decreased the microleakage, increased the tensile bond strength between the two materials and did not make the initial bending strength of denture base resin decline.
评估用化学蚀刻剂对义齿基托树脂表面进行预处理，对硅基弹性衬垫与义齿基托树脂之间微渗漏及粘结强度的影响。同时检测表面预处理后义齿基托树脂的初始弯曲强度。
制备36个聚甲基丙烯酸甲酯（PMMA）义齿基托树脂块（30mm×30mm×2mm），分为三组：丙酮组、甲基丙烯酸甲酯（MMA）组和对照组。随后，在每两个树脂块之间施加2mm厚的硅基弹性衬垫。在热循环仪中经过5000次循环（5℃和55℃）后，将其浸入（131）I溶液中24小时，测量γ射线计数。另外制备36个PMMA树脂块（30mm×10mm×7.5mm）。将这些树脂块分为三组并按上述方法处理。在每两个树脂块之间施加3mm厚的硅基弹性衬垫。经过5000次热循环后，在万能试验机上测量样品的拉伸粘结强度。另外制备18个PMMA树脂块（65mm×10mm×3.3mm）。将它们分为3组并以相同方式处理。施加粘合剂后，用三点弯曲试验测量弯曲强度。
两个实验组的微渗漏率较低（520.0±562.2和493.5±447.9），拉伸粘结强度较高[（1.5±0.4）和（1.4±0.5）MPa]，高于对照组[微渗漏率：（1369.5±590.2）；拉伸粘结强度：（0.9±0.2）MPa，P<0.05]。丙酮组和MMA组在微渗漏率和拉伸粘结强度方面无统计学显著差异（P>0.05）。三组之间的弯曲强度无统计学显著差异（P>0.05）。
用丙酮和MMA处理义齿基托树脂表面可降低微渗漏率，增加两种材料之间的拉伸粘结强度，且不会使义齿基托树脂的初始弯曲强度下降。
