Department of Dental Materials and Prosthodontics, Araraquara Dental School, Sao Paulo State University, UNESP, Araraquara, Sao Paulo, Brazil.
Gerodontology. 2011 Jun;28(2):121-6. doi: 10.1111/j.1741-2358.2009.00332.x. Epub 2010 Jan 14.
Microleakage is a pre-stage of debonding between hard chairside relines and denture base acrylic resins. Therefore, it is important to assess them with regard to the longevity of the relined denture. This study investigated the effect of thermal cycling on the microleakage at the interface of three hard chairside reline resins and three denture base resins.
Rectangular bars (12 mm × 3 mm × 3 mm) of Lucitone 550, Acron MC and QC 20 were made and relined with Kooliner, Tokuyama Rebase Fast II and Ufi Gel Hard, Lucitone 550, Acron MC and QC 20 resins. Specimens were divided into one control and two test groups (n=10). In specimens of the control group, the microleakage was performed after the reline procedure. In Test Group 1, the specimens were stored for 24 h in distilled water at room temperature and in Test Group 2; the specimens were thermal cycled from 5 to 55°C for 5000 cycles with a 30-s dwell time. Subsequently, all specimens were immersed in 50% silver nitrate solutions for 24h. All specimens were sectioned longitudinally into three fractions and the lateral sections were examined (n=20). Silver nitrate stain penetration was examined under a stereoscopic lens with ×30 magnification, and the images were captured. Leica Qwin image analysis software was used to determine microleakage at the interface of the materials. Data were analysed using the Kruskal-Wallis test at a 95% level of significance.
For all cycles, there were no statistically significant differences between thermal cycled and non-thermal cycled groups (p>0.05).
It can be concluded that thermal cycling had no effect on the microleakage.
微渗漏是硬面衬垫和义齿基托树脂之间脱粘的前期阶段。因此，评估其与修复义齿寿命的关系非常重要。本研究调查了热循环对三种硬面衬垫树脂和三种义齿基托树脂界面微渗漏的影响。
制作 Lucitone 550、Acron MC 和 QC 20 的矩形棒（12mm×3mm×3mm），并用 Kooliner、Tokuyama Rebase Fast II 和 Ufi Gel Hard、Lucitone 550、Acron MC 和 QC 20 树脂进行衬垫。标本分为一组对照和两组试验（n=10）。在对照组标本中，在衬垫后进行微渗漏。在试验组 1 中，标本在室温下的蒸馏水中储存 24 小时，在试验组 2 中，标本在 5 至 55°C 之间热循环 5000 次，停留时间为 30 秒。随后，所有标本均在 50%硝酸银溶液中浸泡 24 小时。所有标本均沿纵向分为三部分，检查侧向部分（n=20）。在立体显微镜下用 ×30 放大倍数检查硝酸银染色渗透情况，并拍摄图像。使用 Leica Qwin 图像分析软件确定材料界面的微渗漏。使用 Kruskal-Wallis 检验在 95%置信水平下分析数据。
对于所有循环，热循环组和非热循环组之间无统计学差异（p>0.05）。
可以得出结论，热循环对微渗漏没有影响。
