This study investigated effects of the from three light curing units (LCUs): (i) a (Monet); (ii) a (PinkWave); (iii) a conventional LED (Elipar S10) on the temperature rise (ΔT) and degree of conversion (DC) when photo-curing fast or conventional bulk-fill resin-based composites (RBC). The aim was to correlate ΔT and DC, and the radiant exposure delivered to RBC specimens. A 3D-printed resin mold of 4 mm depth was filled with two bulk-fill RBCs: Tetric PowerFill® ( photo-polymerised composite) () or Tetric EvoCeram® Bulk-Fill (). Three LCUs were used: (i) Monet for 1 s and 3 s (); (ii) PinkWave used for 3 s in Boost mode () and for 20 s in standard mode (); (iii) Elipar S10 for 5 s () and for 20 s in standard mode (). 2-dimensional temperature maps were obtained before, during and for 60 s after the LCU had turned off using a thermal imaging camera. Thermal changes were analysed at five depths: (0, 1, 2, 3, and 4 mm from the top surface of the RBC). The maximum temperature rise () and the mean temperature rise () were determined. Cylindrical-shaped specimens were prepared from each material using a stainless-steel split mold (4 × 4 mm) and light-cured with the same protocols. The DC was measured for 120 s and at 1 h after LCU had turned off using Fourier Transform Infrared Spectroscopy (FTIR). Data were analysed using Three-way ANOVA, One-way ANOVA, independent t-tests, and Tukey tests (p < 0.05). Radiant exposures delivered by the various irradiation protocols were between 4.5–30.3 J/cm. Short exposure times from MONET-1 s and PW-3 s delivered the lowest radiant exposures (4.5 and 5.2 J/cm, respectively) and produced the lowest ΔT and DC. The longer exposure times in the standard modes of PW-20 s, S10–20 s, and MONET-3 s produced the highest T, ΔT, and DC for both composites. The ΔT range among composites at different depths varied significantly (31.7–49.9 °C). DC of TPF ranged between 30–65% and in EVO between 15.3–56%. TPF had higher T ΔT for all depths and DC compared to EVO, across the LCU protocols (p < 0.05), except for PW-20 s and MONET-3 s. The coronal part of the restorations (1–2 mm) had the highest ΔT. There was a positive correlation between ΔT and DC at 4-mm depth after 120 s Longer, or standard, exposure times of the LCUs delivered greater radiant exposures and had higher DC and ΔT compared to shorter or high-irradiance protocols. The RBC had comparatively superior thermal and conversion outcomes when it received a high irradiance for a short time (1–5 s) compared to the RBC.

中文翻译：

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与传统固化灯相比，使用四波和激光固化灯进行光固化的快速固化复合材料的热成像和转换

本研究调查了三种光固化单元 (LCU) 的影响：(i) a (Monet)；(ii) a (PinkWave)；(iii) 传统 LED (Elipar S10) 在快速光固化或传统散装填充树脂基复合材料 (RBC) 时的温升 (ΔT) 和转换度 (DC)。目的是将 ΔT 和 DC 以及传递给红细胞样本的辐射暴露关联起来。4 毫米深的 3D 打印树脂模具中填充了两种散装填充红细胞：Tetric PowerFill®（光聚合复合材料）() 或 Tetric EvoCeram® Bulk-Fill ()。使用了三个 LCU：(i) Monet 为 1 秒和 3 秒 ()；(ii) PinkWave 在 Boost 模式下使用 3 秒 ()，在标准模式下使用 20 秒 ()；(iii) Elipar S10 在标准模式下持续 5 秒 () 和 20 秒 ()。使用热像仪获得 LCU 关闭之前、期间和之后 60 秒的二维温度图。在五个深度处分析热变化：（距红细胞顶面 0、1、2、3 和 4 毫米）。确定最大温升 () 和平均温升 ()。使用不锈钢分体模具（4 × 4 毫米）从每种材料制备圆柱形样品，并使用相同的方案进行光固化。使用傅立叶变换红外光谱 (FTIR) 测量 120 秒和 LCU 关闭后 1 小时的 DC。使用三因素方差分析、单因素方差分析、独立 t 检验和 Tukey 检验对数据进行分析 (p < 0.05)。各种辐照方案产生的辐射暴露量在 4.5–30.3 J/cm 之间。MONET-1 s 和 PW-3 s 的短曝光时间提供了最低的辐射暴露（分别为 4.5 和 5.2 J/cm），并产生最低的 ΔT 和 DC。PW-20 s、S10–20 s 和 MONET-3 s 标准模式下的较长曝光时间使两种复合材料产生了最高的 T、ΔT 和 DC。不同深度复合材料的 ΔT 范围差异很大（31.7-49.9 °C）。TPF 的 DC 范围在 30-65% 之间，EVO 的 DC 范围在 15.3-56% 之间。与 EVO 相比，在所有 LCU 协议中，TPF 在所有深度和 DC 上都具有更高的 T ΔT (p < 0.05)，PW-20 s 和 MONET-3 s 除外。修复体的冠状部分（1-2 毫米）具有最高的 ΔT。120 秒后 4 毫米深度处的 ΔT 和 DC 之间呈正相关。与较短或高辐照度方案相比，较长或标准的 LCU 暴露时间可提供更大的辐射暴露，并且具有更高的 DC 和 ΔT。与 RBC 相比，RBC 在短时间内（1-5 秒）接受高辐照度时具有相对优越的热和转化结果。