Grasel Rafaella, Butler Sheila, Santos Gildo C, Santos Maria Jacinta
Gen Dent. 2020 Jul-Aug;68(4):44-48.
This study aimed to evaluate the effect of different LED irradiance levels on the degree of conversion (DC) of dual-cured resin luting agents photocured through a high-translucency zirconia disc. Fifty-four disc specimens (approximately 0.1 × 6.0 × 6.0 mm) were prepared using 3 dual-cured resin luting agents (Panavia F 2.0, RelyX Unicem 2 Automix, and Calibra). Eighteen groups (n = 3) were evaluated. Test specimens were photocured through a 0.7 × 10.0-mm, high-translucency zirconia disc for 20 seconds using 1 of 3 different LED irradiances (mean output of 855, 1330, or 1750 mW/cm after 3 consecutive measurements with an LED radiometer). Specimens photocured directly, without a zirconia disc, were used as controls. Microattenuated total reflectance/Fourier-transform infrared spectroscopy was used to evaluate the extent of polymerization of all specimens prior to curing (baseline) and 24 hours after curing. Data were analyzed by 3-way analysis of variance and Tukey multiple comparisons test (α = 0.05). The RelyX Unicem 2 Automix and Panavia F 2.0 specimens showed no statistically significant difference in the mean DC after the use of different LED irradiance levels (P = 0.15 and P = 0.91, respectively) or when photocured with or without the use of a zirconia disc (P = 0.56 and P = 0.86, respectively). The Calibra specimens cured at the lowest irradiance level (855 mW/cm) presented a significantly lower mean DC (P = 0.001). However, there was no statistically significant difference in the mean DC values when Calibra was photocured directly or through a zirconia disc (P = 0.33). The interpositioning of a high-translucency zirconia material did not reduce the DC of the tested resin luting agents compared to directly irradiated resin luting agents. The influence of different LED irradiance levels on the DC of dual-cured resin luting agents was material dependent.
本研究旨在评估不同LED辐照度水平对通过高透明度氧化锆盘光固化的双固化树脂粘接剂的转化率（DC）的影响。使用3种双固化树脂粘接剂（Panavia F 2.0、RelyX Unicem 2 Automix和Calibra）制备了54个盘状试样（约0.1×6.0×6.0 mm）。评估了18组（n = 3）。使用3种不同LED辐照度（用LED辐射计连续测量3次后平均输出为855、1330或1750 mW/cm²）中的一种，通过0.7×10.0-mm的高透明度氧化锆盘对测试试样光固化20秒。直接光固化、不使用氧化锆盘的试样用作对照。使用微衰减全反射/傅里叶变换红外光谱法评估所有试样在固化前（基线）和固化后24小时的聚合程度。数据通过三因素方差分析和Tukey多重比较检验进行分析（α = 0.05）。使用不同LED辐照度水平后，RelyX Unicem 2 Automix和Panavia F 2.0试样的平均DC无统计学显著差异（分别为P = 0.15和P = 0.91），无论是否使用氧化锆盘进行光固化（分别为P = 0.56和P = 0.86）。在最低辐照度水平（855 mW/cm²）下固化的Calibra试样的平均DC显著较低（P = 0.001）。然而，直接对Calibra进行光固化或通过氧化锆盘进行光固化时，平均DC值无统计学显著差异（P = 0.33）。与直接辐照的树脂粘接剂相比，高透明度氧化锆材料的插入并未降低测试树脂粘接剂的DC。不同LED辐照度水平对双固化树脂粘接剂DC的影响取决于材料。
