Sinhoreti Mário Alexandre Coelho, Manetta Izabella Paola, Tango Rubens Nisie, Iriyama Nelson Tetsu, Consani Rafael Leonardo Xediek, Correr-Sobrinho Lourenço
Dental Materials Area, Department of Restorative Dentistry, School of Dentistry of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil.
Braz Dent J. 2007;18(4):305-8. doi: 10.1590/s0103-64402007000400006.
This study evaluated, using Knoop hardness test, the polymerization depth of Rely-X dual-cured resin cement activated by chemical reaction alone (control group) or by chemical/physical mode with light curing through a 1.5-mm-thick ceramic layer (HeraCeram). Bovine incisors had their buccal surface flattened and hybridized. On this surface, a rubber mould (5 mm diameter; 1 mm high) was bulk filled with cement. Either a polyester strip or a 1.5-mm-thick disc of the veneering material was seated over this set. Light curing was performed with either conventional halogen light (QTH; XL2500) for 40 s, light-emitting diode (LED; Ultrablue Is) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. In a control group, cement setting occurred by chemical reaction alone. After storage dry in dark (24 h/37 degrees C), the specimens (n=5) were sectioned for hardness (KHN) measurements at three depths in a microhardness tester (50 gf load/15 s). Data were submitted to ANOVA and Tukey's test (alpha = 0.05). Rely-X cement presented higher Knoop hardness values when the QTH and LED LCUs were used, compared to the control group and PAC. Light curing with PAC resulted in lower hardness compared to the control group. Cement hardness was significantly lower in deeper regions.
本研究使用努氏硬度测试，评估了仅通过化学反应活化的Rely-X双固化树脂水门汀（对照组）或通过化学/物理模式并通过1.5毫米厚的陶瓷层（HeraCeram）进行光固化的聚合深度。将牛切牙的颊面磨平并进行酸蚀处理。在该表面上，用树脂水门汀填充一个橡胶模具（直径5毫米；高1毫米）。在其上放置一块聚酯条或一块1.5毫米厚的贴面材料圆盘。分别使用传统卤素灯（QTH；XL2500）照射40秒、发光二极管（LED；Ultrablue Is）照射40秒或氙等离子弧（PAC；Apollo 95E）照射3秒进行光固化。在对照组中，树脂水门汀仅通过化学反应固化。在黑暗中干燥储存（24小时/37℃）后，将样本（n = 5）在显微硬度测试仪中以50 gf载荷/15秒在三个深度处切片进行硬度（KHN）测量。数据进行方差分析和Tukey检验（α = 0.05）。与对照组和PAC相比，当使用QTH和LED光固化单元时，Rely-X树脂水门汀呈现出更高的努氏硬度值。与对照组相比，用PAC进行光固化导致硬度较低。在较深区域，树脂水门汀的硬度明显较低。
