Department of Restorative Dentistry, Indiana University School of Dentistry, Indianapolis, IN, USA.
Oper Dent. 2009 Nov-Dec;34(6):703-8. doi: 10.2341/08-120-L.
This study determined the effect of bleaching agents on the fracture toughness of composite materials. Four nanofilled resin composites were evaluated: Filtek Supreme Plus, Tetric EvoCeram, Premise and Esthet-X. Four concentrations of bleaching agents were tested: Opalescence PF 10%, 20%, 35% and 45%. Fifty specimens of each composite conforming to ASTM guidelines for the single edge notch bar-shaped specimen were fabricated in a metal mold. The specimens were stored in artificial saliva at 37 degrees C for a minimum of 24 hours prior to exposing them to the bleaching agents. Ten specimens of each material were used as controls. Forty specimens of each brand were evenly divided into four groups for bleaching agent application (n = 10). The resin composites were bleached on both sides for 14 days. The specimens were then subjected to a three-point bending test with a crosshead speed of 0.2 mm per second. The fracture toughness (K(Ic)) was calculated. The control group K(Ic) value of Esthet-X was significantly higher than that of the other composites in the controlled groups. Bleaching agents significantly improved the fracture toughness values of Filtek Supreme Plus. The application of bleaching agents did not significantly change the fracture toughness values of the other nanofilled resin composites tested.
本研究旨在确定漂白剂对复合材料断裂韧性的影响。评估了四种纳米复合树脂材料：Filtek Supreme Plus、Tetric EvoCeram、Premise 和 Esthet-X。测试了四种浓度的漂白剂：Opalescence PF 10%、20%、35%和 45%。根据 ASTM 单边缺口梁形试样指南，在金属模具中制作了符合规范的每种复合材料的 50 个样本。将样本储存在 37°C 的人工唾液中至少 24 小时，然后将其暴露于漂白剂中。每种材料的 10 个样本作为对照。每种品牌的 40 个样本均匀分为 4 组进行漂白剂应用（n = 10）。将树脂复合材料的两侧漂白 14 天。然后，以 0.2 毫米/秒的十字头速度对样本进行三点弯曲测试。计算断裂韧性（K(Ic)）。在对照组中，Esthet-X 的对照 K(Ic) 值明显高于其他对照复合材料。漂白剂显著提高了 Filtek Supreme Plus 的断裂韧性值。应用漂白剂对其他测试的纳米复合树脂复合材料的断裂韧性值没有显著影响。
