Department of Prosthodontics, Dentistry School, University of Taubaté, SP, Brazil.
J Adhes Dent. 2013 Feb;15(1):33-9. doi: 10.3290/j.jad.a28173.
To evaluate the Knoop hardness (KH) and the bond strength (BS) at the tooth/restoration interface of conventional methacrylate- (Filtek Supreme) and silorane-based (Filtek P90) composites photoactivated by different methods using an LED Freelight 2.
Bond strength was tested in a universal testing machine by the "push-out" test in restored cavities measuring 2 × 1.5 × 2 mm with a C-factor of 2.2, prepared in 60 bovine teeth. To restore the cavities, the respective adhesive system of each composite was used (Single Bond 2 and P90 system adhesives). The composites were photoactivated by 3 different methods: continuous light: 40 s at 1000 mW/cm²; soft-start: 10 s at 150 mW/cm² + 38 s at 1000 mW/cm²; pulse delay: 5 s at 150 mW/cm², followed by a 3-min wait (without photoactivation) and 39 s at 1000 mW/cm². Before the push-out test was performed, the KH was analyzed at the top and bottom of the restorations. Data were statistically anaylzed using ANOVA and Tukey's test.
The photoactivation methods produced no differences in BS or KH in the same composite, while Filtek P90 (28.0 MPa) showed higher BS values than Filtek Supreme (22.3 MPa) and a lower KH.
The composite Filtek P90 was capable of increasing bond strength, but presented lower Knoop hardness.
评估使用不同方法（LED Freelight 2）光固化的传统甲基丙烯酸酯基（Filtek Supreme）和硅烷醇基（Filtek P90）复合材料的 Knoop 硬度（KH）和牙体/修复体界面的结合强度（BS）。
通过“推出”试验在 60 颗牛牙上制备的 2×1.5×2mm 带有 2.2C 因子的修复腔中，在万能试验机上测试结合强度。为了修复这些腔，使用了每种复合材料的相应粘接系统（Single Bond 2 和 P90 系统胶粘剂）。用 3 种不同方法对复合材料进行光固化：连续光：1000mW/cm²，40s；软启动：150mW/cm²，10s+1000mW/cm²，38s；脉冲延迟：150mW/cm²，5s，然后等待 3 分钟（无光激活），再进行 1000mW/cm²，39s。在进行推出试验之前，在修复体的顶部和底部分析 KH。使用方差分析和 Tukey 检验对数据进行统计学分析。
在同一复合材料中，光固化方法对 BS 或 KH 没有差异，而 Filtek P90（28.0MPa）的 BS 值高于 Filtek Supreme（22.3MPa），KH 值较低。
复合材料 Filtek P90 能够提高结合强度，但 KH 值较低。
