Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, 56 Lingyuan West Road, Guangzhou 510055, China.
Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
J Prosthodont Res. 2020 Apr;64(2):137-144. doi: 10.1016/j.jpor.2019.06.002. Epub 2019 Dec 18.
To investigate the effects of different curing modes, including tack cure, on the degree of conversion (DC) and mechanical parameters of dual-cured luting agents for all-ceramic restorations.
Immediate light curing, intermittent light curing (2-s tack cure and a 1-min interval before the main cure), delayed light cuing (2-min delay) and chemical or no light curing were used to cure two dual-cured luting agents, RelyX Unicem and PermaCem 2.0, through a 1.5-mm thick lithium disilicate ceramic slide. DC (n=3), micro-hardness (n=5), shrinkage strain (n=4) and shrinkage stress (n=3) were measured under the aforementioned curing modes. The data were analyzed using two-way ANOVA and post-hoc Tukey HSD test, with the level of significance set at α=0.05.
For both luting agents, all the light-curing modes produced similar final DC, but using chemical cure only could significantly reduce the DC. The mechanical parameters followed a similar pattern. There were positive but nonlinear correlations between DC and the other mechanical parameters, with the increase in these parameters with DC being slower initially.
Provided adequate light curing is applied to a dual-cured luting agent, delaying the light curing or using a tack cure first to facilitate seating of a restoration may not have a significant impact on the luting agent's final degree of conversion. However, using chemical cure only may result in inadequate cure of the luting agent and is recommended only for highly opaque restorations.
研究不同固化模式（包括初固）对全瓷修复用双固化黏结剂的转化率（DC）和力学性能的影响。
通过 1.5mm 厚的锂硅二硅酸锂陶瓷片，对两种双固化黏结剂 RelyX Unicem 和 PermaCem 2.0 采用即刻光固化、间歇光固化（初固 2s 后间隔 1min 进行主固化）、延迟光固化（延迟 2min）和化学或无光照固化进行固化。在上述固化模式下，分别测量 DC（n=3）、显微硬度（n=5）、收缩应变（n=4）和收缩应力（n=3）。采用双因素方差分析和事后 Tukey HSD 检验对数据进行分析，显著性水平设为α=0.05。
对于两种黏结剂，所有光固化模式的最终 DC 均相似，但仅使用化学固化可显著降低 DC。力学参数也呈现出类似的模式。DC 与其他力学参数之间存在正相关但非线性关系，这些参数随 DC 的增加初始增加较慢。
只要对双固化黏结剂进行充分的光照固化，延迟光照固化或先进行初固以利于修复体就位，可能不会对黏结剂的最终转化率产生显著影响。然而，仅使用化学固化可能导致黏结剂固化不足，仅推荐用于高不透明修复体。
