Ilie Nicoleta, Hickel Reinhard
Department of Restorative Dentistry, Dental School of the Ludwig-Maximilians-University, Munich, Germany.
Am J Dent. 2007 Aug;20(4):263-8.
To analyze the curing behavior and the curing quality of a nano-hybrid composite material (Tetric EvoCeram) in relation to degree of cure, variation of hardness with depth and polymerization depth.
The composite was evaluated after polymerizing the material with 13 different curing regimens of two LED devices and one halogen curing unit by assessing in real time the degree of cure at depths of 2 and 6 mm, the variation of hardness with depth and the polymerization depth. The sample preparation simulated the clinical incremental technique as well as a bulk fill procedure.
No correlation was found for the tested curing regimens between polymerization depth and surface hardness respectively between surface hardness and radiant exposure, whereas the polymerization depth was strongly dependent on polymerization time and radiant exposure. It can be therefore concluded that the surface hardness is not a reliable indicator of the quality of curing. The degree of cure was strongly influenced by depth and curing time, whereas the influence of the curing regimen and of the interaction products between these three factors was low. The higher effect on the variation of the Vickers hardness, measured 24 hours after polymerization, was exercised also by the depth, followed by curing regimen and curing time.
分析纳米混合复合材料（Tetric EvoCeram）的固化行为和固化质量，涉及固化程度、硬度随深度的变化以及聚合深度。
通过实时评估2毫米和6毫米深度处的固化程度、硬度随深度的变化以及聚合深度，对使用两种LED设备和一个卤素固化单元的13种不同固化方案聚合后的复合材料进行评估。样品制备模拟了临床分层技术以及一次充填操作。
在所测试的固化方案中，聚合深度与表面硬度之间以及表面硬度与辐射暴露之间均未发现相关性，而聚合深度强烈依赖于聚合时间和辐射暴露。因此可以得出结论，表面硬度不是固化质量的可靠指标。固化程度受深度和固化时间的强烈影响，而固化方案以及这三个因素之间的相互作用产物的影响较小。聚合24小时后测量的维氏硬度变化受深度影响更大，其次是固化方案和固化时间。
