Eick J David, Kotha Shiva P, Chappelow Cecil C, Kilway Kathleen V, Giese Gregory J, Glaros Alan G, Pinzino Charles S
Department of Oral Biology, University of Missouri-Kansas City, Kansas City, MO, USA.
Dent Mater. 2007 Aug;23(8):1011-7. doi: 10.1016/j.dental.2006.09.002. Epub 2006 Nov 9.
To evaluate properties of silorane-based resins and composites containing a stress reducing monomer.
Resin mixtures and composites were formulated containing (a) a developmental stress reducing monomer [TOSU; Midwest Research Institute]; (b) Sil-Mix (3M-ESPE); (c) photo cationic initiator system. Standard BISGMA/TEGDMA resin (B/T) and composite (Filtek Z250) were used as controls. Polymerization volume change was measured using a NIST mercury dilatometer and polymerization stress using an Enduratec mechanical testing machine. Three point bend tests determined flexural elastic modulus, work of fracture, and ultimate strength (ADA 27; ISO 4049). Fracture toughness was measured using ASTM E399-90. Four groups of resins and composites were tested: Sil-Mix, methacrylate standard, and Sil-Mix with two addition levels of TOSU. An ANOVA was used and significant differences ranked using Student-Newman-Keuls test (alpha=0.05).
Polymerization stress values for resins containing TOSU were significantly less than the other materials. Polymerization shrinkage values for Sil-Mix formulations were significantly less than for B/T, but were not different from each other. TOSU-containing formulations generally had somewhat lower mechanical properties values than Sil-Mix or B/T. Polymerization stress values for Sil-Mix-based composites were significantly less as compared to Z250. The 1wt.% TOSU composite had the lowest stress. No difference between composite groups was noted for fracture toughness or work of fracture. For ultimate strength, the 5wt.% TOSU formulation differed significantly from Z250. All Sil-Mix formulations had elastic modulus values significantly different from Z250.
The ability of TOSU to reduce polymerization stress without a proportional reduction in mechanical properties provides a basis for improvement of silorane-based composites.
评估含应力降低单体的硅氧烷类树脂和复合材料的性能。
配制树脂混合物和复合材料，其中包含（a）一种研发中的应力降低单体[TOSU；中西部研究所]；（b）Sil-Mix（3M-ESPE）；（c）光阳离子引发体系。使用标准双酚A双甲基丙烯酸缩水甘油酯/三乙二醇二甲基丙烯酸酯树脂（B/T）和复合材料（Filtek Z250）作为对照。使用美国国家标准与技术研究院汞膨胀计测量聚合体积变化，使用Enduratec机械试验机测量聚合应力。三点弯曲试验测定弯曲弹性模量、断裂功和极限强度（ADA 27；ISO 4049）。使用ASTM E399-90测量断裂韧性。测试四组树脂和复合材料：Sil-Mix、甲基丙烯酸酯标准品以及添加两种不同水平TOSU的Sil-Mix。采用方差分析，并使用Student-Newman-Keuls检验对显著差异进行排序（α=0.05）。
含TOSU的树脂的聚合应力值显著低于其他材料。Sil-Mix配方的聚合收缩值显著低于B/T，但彼此之间无差异。含TOSU的配方的机械性能值通常略低于Sil-Mix或B/T。与Z250相比，基于Sil-Mix的复合材料的聚合应力值显著更低。1wt.% TOSU复合材料的应力最低。在断裂韧性或断裂功方面，复合材料组之间未观察到差异。对于极限强度，5wt.% TOSU配方与Z250有显著差异。所有Sil-Mix配方的弹性模量值与Z250有显著差异。
TOSU在不按比例降低机械性能的情况下降低聚合应力的能力为改进硅氧烷类复合材料提供了依据。
