Int J Prosthodont. 2019 Nov/Dec;32(6):533-540. doi: 10.11607/ijp.6405.
To investigate the need for photoactivation of the adhesive system inside ceramic laminates before the luting procedure and to evaluate the color stability, nanohardness, and elastic modulus of the adhesive interface activated with singlewave and polywave light-curing units.
A total of 44 lithium disilicate ceramic veneers (7.0 mm × 8.0 mm × 0.6 mm) were fabricated, bonded to enamel, and sorted into four experimental groups (n = 11 each) according to the type of light-curing unit (Radii-Cal [singlewave] or Valo [polywave]) and mode of adhesive system activation (with or without previous photoactivation). Two luting agents were used: the Tetric N-Bond adhesive system and Variolink Veneer resin cement. A visible ultraviolet spectrophotometer was used to evaluate the color stability before and after UVB artificial accelerated aging for 252, 504, and 756 hours (n = 8 samples from each group). A nanohardness tester under a load of 1,000 μN was used to evaluate the nanohardness and elastic modulus (n = 3 samples from each group). Data regarding the color stability and the mechanical properties (nanohardness and elastic modulus) were subjected to analysis of variance and Tukey protected least significant difference test (α = .05).
Prior activation of the adhesive system, the distinct light-curing units, and different aging periods exerted no significant difference on the color stability or mechanical properties of the resin cement (P > .05), except for in the group activated with Radii-Cal after 756 hours, in which the nonprevious activation showed lower color alteration compared to the previous photoactivation (P = .0285). Without prior activation of the adhesive with Valo, the polywave unit promoted higher nanohardness and elastic modulus values in the adhesive system (P < .05).
In general, singlewave and polywave light-curing units promoted no difference in color stability or the mechanical properties of the adhesive interface. The prior curing of an adhesive system inside ceramic laminate is not necessary.
研究在粘固程序前对陶瓷嵌体内部的粘结系统进行光活化的必要性，并评估单波长和多波长光固化机对粘结界面进行激活后的颜色稳定性、纳米硬度和弹性模量。
共制作 44 个锂硅二酸盐陶瓷贴面（7.0mm×8.0mm×0.6mm），粘结到牙釉质上，并根据光固化机的类型（Radii-Cal[单波长]或 Valo[多波长]）和粘结系统激活模式（是否预先进行光活化）分为四组（每组 n = 11）。使用两种粘固剂：Tetric N-Bond 粘结系统和 Variolink 贴面树脂水泥。使用可见紫外分光光度计在 UVB 人工加速老化 252、504 和 756 小时后评估颜色稳定性（每组 8 个样本）。使用负载为 1000μN 的纳米硬度测试仪评估纳米硬度和弹性模量（每组 3 个样本）。对颜色稳定性和机械性能（纳米硬度和弹性模量）的数据进行方差分析和 Tukey 保护最小显著差异检验（α=0.05）。
在预先激活粘结系统、使用不同的光固化机和不同的老化时间的情况下，除了在 756 小时后用 Radii-Cal 激活的组中，未预先激活的组显示出比预先光活化的组更低的颜色变化（P=0.0285）外，粘结系统的颜色稳定性或机械性能没有显著差异。如果在使用 Valo 之前不预先激活粘结剂，多波长单元会使粘结系统中的纳米硬度和弹性模量值更高（P<0.05）。
一般来说，单波长和多波长光固化机对粘结界面的颜色稳定性或机械性能没有影响。在陶瓷嵌体内部的粘结系统进行预先固化不是必需的。
