The University of Edinburgh, Edinburgh Postgraduate Dental Institute, Lauriston Place, Edinburgh EH3 9HA, UK.
J Dent. 2012 Jul;40(7):577-84. doi: 10.1016/j.jdent.2012.03.007. Epub 2012 Mar 29.
To determine the degree of conversion (DC) and Knoop microhardness (KHN) of resin-based composites (RBCs) containing trimethylbenzoyl-diphenylphosphine oxide (TPO) cured by polywave or monowave LED light-curing units (LCUs).
Three groups (each n = 5) of Tetric EvoCeram (Ivoclar Vivadent), Vit-l-escence (Ultradent) and Herculite XRV Ultra (Kerr) were prepared in Teflon moulds (5mm in diameter and 2mm thick) and cured with polywave Bluephase(®) G2 (Ivoclar Vivadent), polywave Valo (Ultradent) or monowave Bluephase(®) (Ivoclar Vivadent; control) resulting in 9 groups. DC and KHN were determined using micro-Raman spectroscopy and Knoop microhardness, respectively. High-performance liquid chromatography and nuclear magnetic resonance spectroscopy were used to confirm the presence or absence of TPO in the three uncured materials. Data were statistically analysed using two-way and one-way ANOVA and DC and KHN were correlated using Pearson's correlation (α = 0.05).
TPO was confirmed in Tetric EvoCeram and Vit-l-escence but not in Herculite XRV Ultra. All three LCUs produced comparable KHN for Tetric EvoCeram and Herculite XRV Ultra (p > 0.05). Both polywave LCUs resulted in significantly higher KHN for Vit-l-escence and higher DC in Tetric EvoCeram and Vit-l-escence than the monowave Bluephase(®) (p < 0.05). Conversely, Bluephase(®) showed higher DC than the two polywave LCUs in Herculite XRV Ultra (p < 0.05). Pearson's correlation coefficient was r = 0.818.
Polywave LED LCUs improved monomer to polymer conversion and KHN in the two TPO-containing RBCs, but not in Herculite XRV Ultra. DC and KHN were linearly correlated in all three RBCs. Vit-l-escence showed the highest DC and KHN of the three materials tested.
The use of polywave LEDs significantly improves both the DC and KHN of materials which contain TPO. This should be taken into account when curing bleached shades of RBCs even if the manufacturers do not indicate the presence of TPO in their materials.
确定含有三甲基苯甲酰基二苯基氧化膦（TPO）的树脂基复合材料（RBC）的转化率（DC）和努普微硬度（KHN），这些 RBC 由多波或单波 LED 光固化单元（LCU）固化。
将三种 Tetric EvoCeram（义获嘉伟瓦登特）、Vit-l-escence（优尔丹）和 Herculite XRV Ultra（ Kerr）组（每组 n = 5）分别在聚四氟乙烯模具（直径 5mm，厚 2mm）中制备，并分别用多波 Bluephase® G2（义获嘉伟瓦登特）、多波 Valo（优尔丹）或单波 Bluephase®（义获嘉伟瓦登特；对照）固化，共得到 9 组。分别采用显微拉曼光谱法和努普微硬度计测定 DC 和 KHN。采用高效液相色谱法和核磁共振波谱法证实三种未固化材料中是否存在 TPO。采用双因素和单因素方差分析对数据进行统计学分析，采用 Pearson 相关性分析（α = 0.05）对 DC 和 KHN 进行相关性分析。
在 Tetric EvoCeram 和 Vit-l-escence 中证实存在 TPO，但在 Herculite XRV Ultra 中不存在。三种 LCU 对 Tetric EvoCeram 和 Herculite XRV Ultra 的 KHN 均具有可比性（p > 0.05）。两种多波 LCU 均使 Vit-l-escence 的 KHN 显著升高，并使 Tetric EvoCeram 和 Vit-l-escence 的 DC 高于单波 Bluephase®（p < 0.05）。相反，Bluephase®在 Herculite XRV Ultra 中的 DC 高于两种多波 LCU（p < 0.05）。Pearson 相关系数 r = 0.818。
多波 LED LCU 提高了两种含 TPO 的 RBC 的单体转化率和 KHN，但对 Herculite XRV Ultra 没有影响。在所有三种 RBC 中，DC 和 KHN 呈线性相关。在三种测试材料中，Vit-l-escence 的 DC 和 KHN 最高。
即使制造商未在其材料中表明存在 TPO，多波 LED 的使用也可显著提高 TPO 含量材料的 DC 和 KHN。在固化漂白后色调的 RBC 时，应考虑到这一点。
