Abstract：
This study evaluated the changes in surface properties of three resin-based restorative materials after two laser-assisted, in-office tooth bleaching protocols using erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) or diode (980 nm) lasers. A nanohybrid composite (Enamel Plus HRi), a Bis-GMA-free composite (Enamel Plus HRi Bio Function), and a resin-matrix CAD-CAM ceramic (Shofu Block HC) were tested. Forty specimens for each material were prepared and divided into four groups (n = 10/group). The control specimens did not undergo any bleaching treatment, whereas group 2 received bleaching with 40% hydrogen peroxide (H2O2), while groups 3 and 4 underwent the same bleaching procedure with the use of diode (980 nm) or Er,Cr:YSGG lasers, respectively. Surface microhardness and roughness measurements were conducted using a Vickers tester and an optical profilometer. Microhardness was lower in bleached specimens, with the nanohybrid composite exhibiting the largest difference from the no bleaching group. For the Bis-GMA-free composite the microhardness difference between no bleaching and laser-assisted bleaching were smaller than seen for the conventional bleaching technique. Surface roughness was higher in bleached specimens, with nanohybrid composite showing the largest differences from the control specimens. The examined laser-assisted tooth bleaching protocols were found not to impact surface microhardness and roughness of the tested resin-based specimens and they are deemed suitable for clinical use.
摘要：
这项研究评估了两种激光辅助后三种树脂基修复材料的表面性能变化，办公室使用铒的牙齿漂白方案，铬:钇-钪-镓-石榴石(Er，Cr:YSGG)或二极管(980nm)激光器。纳米混合复合材料（搪瓷加HRi），不含GMA的双复合材料（搪瓷加HRi生物功能），并对树脂基CAD-CAM陶瓷(ShofuBlockHC)进行了测试。制备每种材料的40个样本并分成4组(n=10/组)。对照样品没有进行任何漂白处理，而第2组接受40%过氧化氢(H2O2)漂白，而第3组和第4组使用二极管（980nm）或Er进行相同的漂白程序，Cr:YSGG激光器，分别。使用维氏测试仪和光学轮廓仪进行表面显微硬度和粗糙度测量。漂白试样的显微硬度较低，纳米杂化复合材料表现出与无漂白基团最大的差异。对于不含Bis-GMA的复合材料，无漂白和激光辅助漂白之间的显微硬度差小于常规漂白技术的显微硬度差。漂白试样的表面粗糙度较高，纳米杂化复合材料显示出与对照样品的最大差异。发现所检查的激光辅助牙齿漂白方案不会影响所测试的基于树脂的样本的表面显微硬度和粗糙度，并且它们被认为适合临床使用。
