Department of Pediatric Dentistry, Dental Research Institute, School of Dentistry, Seoul National University, Seoul National University Dental Hospital, Jongno-gu, Seoul, 03080, Republic of Korea.
Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, 97201.
J Esthet Restor Dent. 2017 Sep;29(5):362-367. doi: 10.1111/jerd.12311. Epub 2017 Jun 19.
The aim of this study was to investigate the effect of shade and opacity on the change in light transmission through different thicknesses of a nano-hybrid composite during curing.
Twelve different shades of Venus Diamond (Heraeus Kulzer) were placed in disk shaped molds with thickness of 1, 2, and 3 mm (n = 3 per group) and cured with an LED light-curing unit. Initial, final and average irradiance, and the total amount of energy passing through the specimen were measured using the MARC Resin Calibrator at every 10s for a total of 40s. The translucency parameter and the contrast ratio were obtained using a chromameter. Results were analyzed with ANOVA/Tukey's test (α = 0.05).
All shades and all thicknesses (up to 3 mm) experienced an increase in light transmittance during curing. The majority of the increase occurred during the initial 10s exposure, with significant increase occurring from subsequent exposures only in thicker specimens (i.e., 3 mm). The increase in irradiance at the bottom during curing was dependent on shade, with darker shades and greater depths of material showing less increase.
For one specific resin composite formulation, an increase in translucency occurs as cure progresses, and the increase is enhanced for composites with greater lightness and lower contrast ratio.
Composites demonstrate increased light transmittance as curing progress, which may improve depth of cure. The thicker composite showed the least increase in light transmission within the same shade. The increase in translucency is enhanced for composites with great lightness and lower contrast ratio.
本研究旨在探讨不同厚度的纳米复合树脂在固化过程中透光率随遮色和不透明度变化的情况。
将 12 种不同色调的 Venus Diamond（贺利氏古莎）分别置于厚度为 1、2 和 3mm 的圆盘模具中（每组 3 个样本），并使用 LED 光固化机进行固化。使用 MARC 树脂校准器在 40s 内的每 10s 测量初始、最终和平均辐照度以及通过试件的总能量。使用分光光度计获得透光率参数和对比率。采用方差分析/Tukey 检验（α=0.05）进行结果分析。
所有色调和所有厚度（最高 3mm）在固化过程中透光率均增加。大部分增加发生在初始 10s 曝光期间，仅在较厚的试件（即 3mm）中随后的曝光中才会出现显著增加。固化过程中底部辐照度的增加取决于色调，较暗的色调和较大的材料深度显示出较小的增加。
对于一种特定的树脂复合配方，随着固化的进行，透光率会增加，并且具有更高明度和更低对比率的复合材料会增强这种增加。
复合材料随着固化的进行显示出增加的光透射率，这可能会提高深度固化。同一色调的较厚复合材料的光透过率增加最小。具有高亮度和低对比度比的复合材料的透光率增加增强。
