Objective

The study used optical coherence tomography (OCT) and micro Raman microscopy (mRM) to investigate internal defect (ID) and degree of conversion (DC) of two bulk-fill composite systems with high-irradiance or conventional light polymerization settings.

Methods

The ID and DC of the new bulk-fill composites; Tetric PowerFill (PwrPst) and Tetric PowerFlow (PwrFlw) were compared with the predecessor bulk-fill composites; Tetric EvoCeram Bulkfill (EvoPst) and Tetric EvoFlow Bulkfill (EvoFlw), using LED light curing unit in two settings; normal (LED-Nrm: 1000 mW/cm², 10-s) or PowerCure (LED-Pwr: 3000 mW/cm², 3-s). ID formation was observed in bonded cylindrical composite cavities (4-mm depth, 3-mm diameter) using Yoshida Dental OCT. From the vertically projected 2D image, ID area percentage (ID-A%) was calculated. DC at the top and bottom and bottom/top DC ratio (DC-R%) of 4-mm thick discs was calculated using mRM. All data were statistically analyzed at significance level of α = 0.05.

Results

Flowable composites in LED-Pwr showed smaller ID frequencies than other groups (PwrFlw: 0/8, EvoFlw: 2/8) (p < 0.05). Composite type significantly affected ID-A%, DC and DC-R% (p < 0.001), while light settings significantly affected ID-A% but not DC and DC-R% (p > 0.05). In both light settings, EvoPst showed the lowest DC-R% (<80%).

Significance

Internal defect and degree of conversion of bulk-fill composites were affected by their composition and light settings. There was a tendency for less defects and better polymerization for the flowable bulk-fills. The new flowable bulk-fill composite with 3-seconds high irradiance light curing showed no defect formation.

中文翻译：

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具有高辐照度光聚合的新型整体填充复合材料系统：完整性和转化度

目的

该研究使用光学相干断层扫描（OCT）和显微拉曼显微镜（mRM）研究了两个具有高辐照度或常规光聚合设置的填充复合系统的内部缺陷（ID）和转化率（DC）。

方法

新的填充复合材料的ID和DC；将Tetric PowerFill（PwrPst）和Tetric PowerFlow（PwrFlw）与之前的散装填充复合材料进行了比较。Tetric EvoCeram批量填充（EvoPst）和Tetric EvoFlow批量填充（EvoFlw），使用两种设置中的LED光固化单元；正常（LED-NRM：1000毫瓦/厘米²，10秒）或PowerCure（LED-PWR：3000毫瓦/厘米²，3-S）。使用Yoshida Dental OCT在粘合的圆柱状复合腔（4毫米深，3毫米直径）中观察到ID的形成。根据垂直投影的2D图像，计算出ID面积百分比（ID-A％）。使用mRM计算4毫米厚光盘的顶部和底部的DC和底部/顶部的DC比（DC-R％）。所有数据均以显着性水平α = 0.05进行统计分析。

结果

LED-Pwr中的可流动复合材料显示出的ID频率低于其他组（PwrFlw：0/8，EvoFlw：2/8）（p <0.05）。复合类型显着影响ID-A％，DC和DC-R％（p <0.001），而灯光设置显着影响ID-A％，但不影响DC和DC-R％（p> 0.05）。在两种照明设置下，EvoPst的DC-R％最低（<80％）。

意义

填充复合材料的内部缺陷和转化率受其组成和光照设置的影响。对于可流动的填充料，存在缺陷较少且聚合更好的趋势。具有3秒高辐照度光固化的新型可流动的块状填充复合材料没有缺陷形成。