Voltarelli Fernanda Regina, Dos Santos-Daroz Claudia Batitucci, Alves Marcelo Correa, Peris Alessandra Rezende, Marchi Giselle Maria
Department of Restorative Dentistry, Piracicaba School of Dentistry, Areiao, Piracicaba, SP, Brazil.
Gen Dent. 2009 Jul-Aug;57(4):314-9; quiz 320-1.
This study evaluated how photocuring devices affected the microhardness of composite resin cylinders. For this study, 120 specimens of composite were fabricated and allocated randomly into 12 groups (n = 10), according to the light source (quartz-tungsten-halogen (QTH), LED, argon laser, plasma arc) and the height of the specimen (2.0, 4.0, or 6.0 mm). Twenty-four hours after the specimens were fabricated, the Knoop microhardness test was performed on bottom and top surfaces. Statistical analysis showed significant interaction among light sources, between light sources and specimen heights, and between the surfaces. Compared to the QTH specimens, the argon laser and plasma arc specimens showed reduced polymerization on the top surface, while the plasma arc specimens showed reduced polymerization on the bottom surface. The 4.0 mm samples demonstrated higher Knoop microhardness than the 2.0 mm and 6.0 mm samples, especially when argon laser and plasma arc curing lights were used. The microhardness was always higher on the top surface than on the bottom surface. No photocuring unit was able to properly polymerize the bottom surface as completely as the top surface.
本研究评估了光固化设备对复合树脂圆柱体微硬度的影响。在本研究中，制备了120个复合树脂标本，并根据光源（石英钨卤素灯（QTH）、发光二极管（LED）、氩激光、等离子弧）和标本高度（2.0、4.0或6.0毫米）随机分为12组（每组n = 10）。标本制备24小时后，在其底面和顶面进行努氏微硬度测试。统计分析表明，光源之间、光源与标本高度之间以及表面之间存在显著的交互作用。与QTH标本相比，氩激光和等离子弧标本在顶面的聚合度降低，而等离子弧标本在底面的聚合度降低。4.0毫米的样本显示出比2.0毫米和6.0毫米的样本更高的努氏微硬度，尤其是在使用氩激光和等离子弧固化灯时。顶面的微硬度始终高于底面。没有任何光固化设备能够使底面的聚合程度与顶面一样完全。
