Schneider Luis Felipe J, Pfeifer Carmem S C, Consani Simonides, Prahl Scott A, Ferracane Jack L
Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
Dent Mater. 2008 Sep;24(9):1169-77. doi: 10.1016/j.dental.2008.01.007. Epub 2008 Mar 5.
To evaluate the degree of conversion (DC), maximum rate of polymerization (Rpmax), Knoop hardness (KHN) and yellowing (b-value) of resin composites formulated with phenylpropanedione (PPD), camphorquinone (CQ), or CQ/PPD at different concentrations. The hypotheses tested were (i) PPD or CQ/PPD would produce less Rpmax and yellowing than CQ alone without affecting DC and KHN, and (ii) Rpmax, DC, and KHN would be directly related to the absorbed power density (PDabs).
CQ/amine, PPD/amine and CQ/PPD/amine were used at low, intermediate and high concentrations in experimental composites. Photoinitiator absorption and halogen-light emission were measured using a spectrophotometer, Rp with differential scanning calorimetry (DSC), DC with DSC and FTIR, KHN with Knoop indentation; and color with a chromameter. The results were analyzed with two-way analysis of variance (ANOVA)/Student-Newman-Keul's test (p<0.05). Correlation tests were carried out between PDabs and each of DC, Rpmax and KHN.
The PDabs increased with photoinitiator concentration and PPD samples had the lowest values. In general, maximum DC was comparable at intermediate concentration, while Rpmax and KHN required higher concentrations. DC was similar for all photoinitiators, but Rpmax was lower with PPD and CQ/PPD. PPD produced the lowest KHN. Yellowing increased with photoinitiator concentration. PPD did not reduce yellowing at intermediate and/or high concentrations, compared to CQ-formulations. PDabs showed significant correlations with DC, Rpmax and KHN.
PPD or CQ/PPD reduced Rpmax in experimental composites without affecting the DC. The use of PPD did not reduce yellowing, but reduced KHN. DC, Rpmax and KHN were dependent on PDabs.
评估用不同浓度的苯丙二酮（PPD）、樟脑醌（CQ）或CQ/PPD配制的树脂复合材料的转化率（DC）、最大聚合速率（Rpmax）、努氏硬度（KHN）和变黄程度（b值）。所检验的假设为：（i）PPD或CQ/PPD在不影响DC和KHN的情况下，产生的Rpmax和变黄程度低于单独使用CQ；（ii）Rpmax、DC和KHN与吸收功率密度（PDabs）直接相关。
在实验性复合材料中以低、中、高浓度使用CQ/胺、PPD/胺和CQ/PPD/胺。使用分光光度计测量光引发剂吸收和卤素光发射，用差示扫描量热法（DSC）测量Rp，用DSC和傅里叶变换红外光谱法（FTIR）测量DC，用努氏压痕法测量KHN；用色差仪测量颜色。结果采用双向方差分析（ANOVA）/Student-Newman-Keul检验进行分析（p<0.05）。在PDabs与DC、Rpmax和KHN中的每一个之间进行相关性测试。
PDabs随光引发剂浓度增加而增加，PPD样品的值最低。一般来说，中等浓度下最大DC相当，而Rpmax和KHN需要更高浓度。所有光引发剂的DC相似，但PPD和CQ/PPD的Rpmax较低。PPD产生的KHN最低。变黄程度随光引发剂浓度增加。与CQ配方相比，PPD在中等和/或高浓度下并未减少变黄。PDabs与DC、Rpmax和KHN显示出显著相关性。
PPD或CQ/PPD在实验性复合材料中降低了Rpmax，但不影响DC。使用PPD并未减少变黄，但降低了KHN。DC、Rpmax和KHN取决于PDabs。
