不同光导头光激活的牙科复合材料的转化率和硬度评估。
Evaluation of degree of conversion and hardness of dental composites photo-activated with different light guide tips.
作者信息
Galvão Marília Regalado, Caldas Sergei Godeiro Fernandes Rabelo, Bagnato Vanderlei Salvador, de Souza Rastelli Alessandra Nara, de Andrade Marcelo Ferrarezi
机构信息
Department of Restorative Dentistry, Araraquara School of Dentistry, Univ. Estadual Paulista-UNESP, Araraquara, SP, BRAZIL ; Department of Dentistry, Rio Grande do Norte Federal University-UFRN, Natal, RN, BRAZIL.
出版信息
Eur J Dent. 2013 Jan;7(1):86-93.
OBJECTIVE
The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer.
METHODS
Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm(-1)) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm(-1)). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey's test, with a significance level set at 5%.
RESULTS
The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001).
CONCLUSIONS
The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness.
目的
本研究旨在评估使用两种不同的导光尖端（光纤和聚合物）对不同复合树脂进行40秒光激活后的转化率和硬度。
方法
对每组评估对象制作五个样本。通过测定样本固化前后脂肪族C═C（1637 cm(-1)处的峰）相对于内标物芳香族C-C（1610 cm(-1)处的峰）的吸光度强度之比，来确定未反应碳双键的百分比（% C═C）。在万能试验机上进行维氏硬度测量。使用50 gf的载荷，压头停留时间为30秒。转化率和硬度平均值分别通过方差分析和Tukey检验进行分析，显著性水平设定为5%。
结果
聚合物和光纤导光尖端的转化率平均值在统计学上存在差异（P<.001）。导光尖端之间的硬度平均值在统计学上存在差异（P<.001），而且顶面和底面之间也存在差异（P<.001）。
结论
结果表明，使用光纤导光尖端光激活的树脂具有更高的转化率和硬度值。
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