Factors Affecting Photopolymerization Stress in Dental Composites
Factors Affecting Photopolymerization Stress in Dental Composites
复制标题
DOI：
10.1177/154405910808701114
复制
发表时间：
2008-11-01
影响因子：
7.6
通讯作者：
Braga, R. R.
中科院分区：
文献类型：
--
作者：
Pfeifer, C. S.;Ferracane, J. L.;Braga, R. R.
聚合应力的发展是体积收缩、反应动力学和粘弹性性质的复杂相互作用的结果。本研究的目的是研究2种双GMA基复合材料的体积收缩、转化率、聚合速率(RPmax)和应力发展之间的关系。使用了220、400或600 mW/cm(2)三种辐照度-调整曝光时间以提供相同的辐射能量。用汞膨胀仪测定体积收缩，用差示扫描量热仪(DSC)测定转化率和RPmax，用低顺应性装置测定聚合应力(Sakaguchi等人，2004b)。结果表明，聚合反应速率与收缩无相关性。光照度与聚合反应速率和应力发展直接相关。具有最高压力/转换程度的组表现出最低的RPmax，因此可以假设，在本研究的限制范围内，转换与压力发展最密切相关。
Polymerization stress development results from the complex interplay of volumetric shrinkage, reaction kinetics, and viscoelastic properties. The objective of this study was to examine the relationships among volumetric shrinkage, degree of conversion, rate of polymerization (RPmax), and stress development for 2 model bis-GMA-based composites. Three irradiances were used 220, 400, or 600 mW/cm(2) - with exposure times adjusted to deliver the same radiant energy. Volumetric shrinkage was determined with a mercury dilatometer, degree of conversion and RPmax by differential scanning calorimetry (DSC), and polymerization stress with a low-compliance device (Sakaguchi et al., 2004b). Results indicated that polymerization reaction rate and shrinkage were not correlated. Irradiance was directly related to polymerization reaction rate and to stress development. The group with the highest stress/degree of conversion exhibited the lowest RPmax, so it can be assumed, within the limitations of this study, that the conversion was most closely related to stress development.