Botega Daniela Maffei, Sanchez José Luiz Lopes, Mesquita Marcelo Ferraz, Henriques Guilherme Elias Pessanha, Consani Rafael Leonardo Xediek
Federal University of Rio Grande do Sul, Dental School, Porto Alegre, Brazil.
J Prosthodont. 2008 Oct;17(7):550-4. doi: 10.1111/j.1532-849X.2008.00342.x. Epub 2008 Aug 26.
This study investigated the effect of in vitro accelerated aging reproduced with thermocycling on the bond strength of three commercially available permanent denture soft liners (PermaSoft, Dentuflex, Ufi-gel) with one heat-polymerized polymethyl methacrylate resin denture base (QC-20) by tensile test.
Ten specimens were prepared for control and test groups of each material for a total of 60 specimens. All controls were stored in water (37 degrees C) for 24 hours before testing. All test groups received 3000 thermal cycles consisting of 1 minute at 5 degrees C and 1 minute at 65 degrees C. All specimens were submitted to a tensile test using a universal testing machine at a crosshead speed of 5 mm/min. Results were statistically analyzed (ANOVA, p < or = 0.05, Tukey's post-hoc test).
The mean bond strength of control specimens was (MPa): 0.32 (Ufi-gel), 0.49 (PermaSoft), and 1.19 (Dentuflex). There was no statistical difference (p > 0.05) between Ufi-gel and PermaSoft, but both were statistically different (p < 0.05) when compared to Dentuflex. After thermocycling, the mean bond strength was (MPa): 0.18 (Ufi-gel), 0.81 (PermaSoft), and 3.32 (Dentuflex). All materials were statistically different (p < 0.05). Ufi-gel had the lowest value and Dentuflex the highest in both control and test groups. Dentuflex presented only adhesive failure; in the remaining groups, there was no predominant failure mode, except Ufi-gel control with no adhesive failure.
Despite presenting greater bond strength, thermocycling had a deleterious effect in Dentuflex; Ufi-gel may be adequate for short-term use.
本研究通过拉伸试验，调查了用热循环模拟体外加速老化对三种市售永久性义齿软衬材料（PermaSoft、Dentuflex、Ufi - gel）与一种热固化聚甲基丙烯酸甲酯树脂义齿基托（QC - 20）之间粘结强度的影响。
每种材料的对照组和试验组均制备10个样本，共60个样本。所有对照组在测试前于37℃水中储存24小时。所有试验组接受3000次热循环，循环包括在5℃下1分钟和在65℃下1分钟。所有样本使用万能试验机以5mm/min的十字头速度进行拉伸试验。结果进行统计学分析（方差分析，p≤0.05，Tukey事后检验）。
对照组样本的平均粘结强度（MPa）为：0.32（Ufi - gel）、0.49（PermaSoft）和1.19（Dentuflex）。Ufi - gel和PermaSoft之间无统计学差异（p＞0.05），但与Dentuflex相比两者均有统计学差异（p＜0.05）。热循环后，平均粘结强度（MPa）为：0.18（Ufi - gel）、0.81（PermaSoft）和3.32（Dentuflex）。所有材料均有统计学差异（p＜0.05）。在对照组和试验组中，Ufi - gel的值最低，Dentuflex的值最高。Dentuflex仅出现粘结破坏；在其余组中，除Ufi - gel对照组无粘结破坏外，无主要的破坏模式。
尽管Dentuflex表现出更高的粘结强度，但热循环对其有有害影响；Ufi - gel可能适用于短期使用。
