Effect of light power density on development of elastic modulus of a model light-activated composite during polymerization.
Effect of light power density on development of elastic modulus of a model light-activated composite during polymerization.
复制标题
光功率密度对聚合过程中模型光激活复合材料弹性模量的影响。
DOI：
10.1111/j.1708-8240.2001.tb00434.x
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Ferracane,JL
中科院分区：
文献类型：
--
作者：
Sakaguchi,RL;Ferracane,JL
目的：复合材料聚合过程中弹性模量的发展是衡量聚合成熟度和修复体向牙本质和牙釉质转移应力能力的指标。弹性模量在固化过程中的实时发展特性在很大程度上是未知的。本研究的目的是评估光功率密度和总能量密度对光活化复合材料弹性模量早期发展的影响。方法：在动态力学分析仪（DMA）中测试混合复合材料模型的圆柱形试样的挠曲。样品被光活化（可变强度聚合剂，Bisco, Itasca, Illinois） 60秒。从光活化开始连续5分钟测量弹性模量。弹性模量的发展评估了六种不同的光功率密度和在较长曝光时间下给出的两种降低功率密度水平，以提供相似的能量密度值。采用Tukey事后比较检验的单因素方差分析来评估弹性模量atp= 0.05的显著性差异。结果：弹性模量的发展速率和最终模量取决于所施加的光功率密度。用短时间、高功率密度或长时间、低功率密度进行等效能量密度固化的复合材料试样产生等效弹性模量。发射功率密度在400 - 600 mW/cm2之间（试样表面测量的160-260 mW/cm2）的弹性模量没有显著差异（p >.05）。结论：在试样表面测量的大于160 mW/cm2的光功率密度导致弹性模量没有显著差异。等效的能量密度产生可比的弹性模量。
Purpose: Elastic modulus development during polymerization of a composite is a measure of the polymerization maturity and the restoration's ability to transfer stress to enamel and dentin. The characteristics of elastic modulus development in real time during cure are largely unknown. The purpose of this study was to evaluate the effect of light power density and total energy density on the early development of elastic modulus for a light‐activated composite.Methods: Cylindrical specimens of a model hybrid composite were tested in flexure in a dynamic mechanical analyzer (DMA). Specimens were light‐activated (Variable Intensity Polymerizer, Bisco, Itasca, Illinois) for 60 seconds. Elastic modulus was measured continuously for 5 minutes from the start of light activation. Development of elastic modulus was assessed for six different light power densities and two reduced power density levels given at longer exposure duration to provide similar energy density values. One‐way analysis of variance with Tukey's post hoc comparison test was used to evaluate significant differences of elastic modulus atp= .05.Results: The rates of elastic modulus development and final moduli were dependent on the light power density applied. Composite specimens cured by equivalent energy densities using short times and high power density or long times and low power density produced equivalent elastic moduli. Elastic moduli for emitted power densities between 400 and 600 mW/cm2(160–260 mW/cm2measured at the specimen surface) were not significantly different (p> .05).Conclusions: Light power densities greater than 160 mW/cm2measured at the specimen surface resulted in elastic moduli that were not significantly different. Equivalent energy densities produced comparable elastic moduli.