Objectives

The purpose of this study was to investigate the effect of high-irradiance light-curing-units (LCUs) on the depth-of-cure (DoC) and degree-of-polymerization (DoP) of bulk-fill composites (BFCs).

Methods

The DoC of composites (Beautifil-Bulk, SHOFU; Filtek-Bulk-Fill, 3 M ESPE; Tetric-EvoCeram-Bulk-Fill, Ivoclar; Sonic-Fill-2, Kerr; Venus-Bulk-Fill, Heraeus; Z250, 3M-ESPE) were measured according to ISO-4049 using high-irradiance LCUs (FlashMax-P3, CMS-Dental; SPEC3, Coltene) and conventional LCU (Paradigm, 3M-ESPE) for exposure times: 3/9-s, 3/20-s, and 10/20-s respectively. Using FTIR, the DoP per composite was measured at the bottom surface as a function of post-curing times for the LCUs at the same exposure times. Data was analyzed with nonlinear regression and ANOVA/Tukey.

Results

Significant differences in DoC were found amongst the LCUs for the various exposure times. All BFCs failed to meet the DoC claimed by manufacturers and failed to satisfy ISO-4049 with the high-irradiance LCUs with 3-s exposures. Standard irradiance and 20-s exposures outperformed all other irradiance-exposure combinations for maximizing the DoC and DoP of BFCs. A minimum of 15.3 J/cm² radiant exposure was required to achieve an adequate maximum polymerization rate. Venus Bulk exhibited the highest DoC and DoP for any LCU-exposure-time combination.

Significance

Among the different combinations of BFCs and LCUs, DoC and DoP were always increased with longer exposure time, but there exists a theoretical radiant-exposure limit beyond which DoP or DoC remains unchanged. However, high DoC or DoP are not always associated with one another. Thus, the exposure-reciprocity law must be approached thoughtfully since irradiance and exposure can independently affect DoP and DoC.

中文翻译：

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高强度固化灯对填充复合材料聚合的影响

目标

这项研究的目的是研究高辐照度光固化单元（LCU）对散装填充复合材料（BFC）的固化深度（DoC）和聚合度（DoP）的影响。

方法

复合材料的DoC（Beautifil-Bulk，SHOFU; Filtek-Bulk-Fill，3 M ESPE; Tetric-EvoCeram-Bulk-Fill，Ivoclar; Sonic-Fill-2，Kerr; Venus-Bulk-Fill，Heraeus; Z250，3M -ESPE）是根据ISO-4049使用高辐射LCU（FlashMax-P3，CMS-Dental; SPEC3，Coltene）和常规LCU（Paradigm，3M-ESPE）测量的曝光时间：3 / 9-s，3 /分别为20秒和10/20秒。使用FTIR，在相同的曝光时间下，在LCU的底部表面上测量每个复合材料的DoP随后固化时间的变化。用非线性回归和ANOVA / Tukey分析数据。

结果

在不同的暴露时间下，LCU之间的DoC有显着差异。所有BFC均未达到制造商要求的DoC要求，并且暴露3 s的高辐照度LCU未能满足ISO-4049的要求。标准辐照度和20秒曝光量要比其他所有辐照度曝光组合要好，才能最大程度地提高BFC的DoC和DoP。为了获得足够的最大聚合速率，至少需要15.3 J / cm ^2的辐射暴露。对于任何LCU曝光时间组合，Venus Bulk都具有最高的DoC和DoP。

意义

在BFC和LCU的不同组合中，DoC和DoP总是随着暴露时间的延长而增加，但是存在理论上的辐射暴露极限，超过此极限DoP或DoC保持不变。但是，高DoC或DoP并不总是彼此关联。因此，由于辐照度和曝光量会独立影响DoP和DoC，因此必须谨慎地考虑曝光度-互易性定律。