Division of Restorative Dentistry, Department of Health Sciences Dental Clinic, University of L'Aquila, L'Aquila, Italy.
Oper Dent. 2013 Jan-Feb;38(1):33-8. doi: 10.2341/11-476-L. Epub 2012 Jul 7.
The aim of this study was to assess the flexural strengths of three resin composites prepared at room temperature or cured after 20 or 40 cycles of preheating to a temperature of 45°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium) (HFO), Enamel Plus HRi (Micerium) (HRi), Opallis + (FGM) (OPA). One group of specimens for each composite was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 20 or 40 preheating cycles to a temperature of 45°C in a preheating device. Ten specimens were prepared for each group. A three-point bending test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with a two-way analysis of variance (ANOVA) test and a Games-Howell test (α = 0.05). The two-way ANOVA showed that both the material and the number of heating cycles were significant factors, able to influence the flexural strength values (p<0.05). However, there was not a statistically significant interaction (p>0.05). For all three composites flexural strengths were not affected after 20 preheating cycles in comparison with the control groups (0 preheating cycles) but were, however, significantly decreased when 40 prewarming cycles were conducted. The HRi and OPA groups had the highest flexural strengths, with no statistically significant differences among them. HFO presented significantly lower flexural strengths in comparison with HRi.
本研究旨在评估三种室温下制备或在预加热至 45°C 温度 20 或 40 个循环后固化的树脂复合材料的弯曲强度。评估了三种树脂复合材料：Enamel Plus HFO（Micerium）（HFO）、Enamel Plus HRi（Micerium）（HRi）、Opallis +（FGM）（OPA）。对于每种复合材料的一组样本，在环境实验室条件下制备，而在其他组中，将复合材料在预热装置中预热至 45°C 温度后，经过 20 或 40 个循环固化。为每个组制备了 10 个样本。使用万能试验机以 0.5mm/min 的十字头速度进行三点弯曲试验。使用双向方差分析（ANOVA）测试和 Games-Howell 测试（α=0.05）对数据进行分析。双向 ANOVA 表明，材料和加热循环次数都是显著因素，能够影响弯曲强度值（p<0.05）。然而，它们之间没有统计学上显著的相互作用（p>0.05）。对于所有三种复合材料，与对照组（0 次预热循环）相比，经过 20 次预热循环后，弯曲强度没有受到影响，但经过 40 次预热循环后，弯曲强度显著降低。HRi 和 OPA 组具有最高的弯曲强度，它们之间没有统计学上的显著差异。HFO 的弯曲强度明显低于 HRi。
