Polymerization contraction of resin composite vs. energy and power density of light-cure
Polymerization contraction of resin composite vs. energy and power density of light-cure
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DOI：
10.1111/j.1600-0722.2005.00239.x
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发表时间：
2005-10-01
影响因子：
1.9
通讯作者：
Peutzfeldt, A
中科院分区：
文献类型：
--
作者：
Asmussen, E;Peutzfeldt, A
这项研究测量了在三个能量密度水平下固化的树脂复合材料的聚合收缩，每个水平都达到了六个不同的功率密度水平。用偏转圆盘法(n=5)记录辐照开始后1h内复合材料的聚合收缩。通过改变距离和商用光固化装置的电源电压，在牙科辐射计上测得50、100、200、400、800和1000 mW cm(-2)的功率密度。用分光光度计记录每个功率密度下的光谱分布。记录了樟脑酚的吸收光谱，计算出各功率密度下的辐射效率为吸收和发射的乘积在波长上的积分。根据收缩曲线的斜率，计算出聚合初始速率R-p的近似值，并将其作为功率密度的替代测量。统计分析表明，随着树脂复合材料接收的能量密度水平的增加，聚合收缩显著增加，而对于每个能量密度水平，收缩随着功率密度的增加而显著减小。
This study measured the polymerization contraction of a resin composite cured at three levels of energy density, each attained at six different levels of power density. The polymerization contraction of the composite was recorded by the method of the deflecting disc (n = 5) for 1 h following the start of irradiation. Power densities of 50, 100, 200, 400, 800 and 1,000 mW cm(-2), as measured on a dental radiometer, were obtained by variation of distance and supply voltage of a commercial light-curing unit. The spectral distribution at each power density was recorded using a spectrophotometer. The absorption spectrum of camphorquinone was also recorded, and the efficiency of the radiation at each power density was calculated as the integral over wavelength of the product of absorption and emission. From the slope of the contraction curves, an approximation to the initial rate of polymerization, R-p, was calculated and was taken as an alternative measure of power density. Statistical analyses showed that polymerization contraction increased significantly with increasing levels of energy density received by the resin composite, and, for each level of energy density, that the contraction decreased significantly with increasing power density.