Pereira Sónia G, Osorio Raquel, Toledano Manuel, Nunes Teresa G
IST/ICTPOL, Departamento de Engenharia de Materiais, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal.
Dent Mater. 2005 Sep;21(9):823-30. doi: 10.1016/j.dental.2005.01.018.
The aim of this study was to investigate the influence of new diluent agents, diluent ratio and filler content, on relevant mechanical properties of several novel composite resins containing Bis-GMA as resin matrices, and to compare these with the properties of composites based on TEGDMA, a conventionally used diluent.
Two Bis-GMA analogues were synthesized and 20 experimental composite resins were prepared combining three monomer mixtures (Bis-GMA/TEGDMA, Bis-GMA/CH3 Bis-GMA and Bis-GMA/CF3 Bis-GMA), at three dilution rates (85/15, 10/90, 0/100) and three levels of hybrid filler content (barium aluminosilicate glass): 0, 10 and 35%. Flexural strength (FS), modulus of elasticity (ME) and microhardness (VHN) of the composites were evaluated. Five specimens of each material were prepared for each mechanical test, light-cured over 120 s and stored in water at 37 degrees C for 1 week. Three-point bending test was used for FS measurement and VHN was quantified by using a Vickers microindentor. Data were analyzed by ANOVA and Student-Newman-Keuls tests (P<0.05).
Materials with CH3 Bis-GMA showed an enhanced VHN. Mean FS was higher for matrices containing TEGDMA. Overall, dilution favored FS and VHN but not ME. Filler loading specially improved ME and VHN.
Results correlate with an increase in the extent of polymerization due to the higher flexibility of the less viscous comonomer starting system and the hydrophobic character of the Bis-GMA analogues.
本研究旨在探讨新型稀释剂、稀释比例和填料含量对几种以双酚A缩水甘油醚甲基丙烯酸酯（Bis-GMA）为树脂基质的新型复合树脂相关力学性能的影响，并将其与基于传统使用的稀释剂三乙二醇二甲基丙烯酸酯（TEGDMA）的复合材料性能进行比较。
合成了两种Bis-GMA类似物，并制备了20种实验性复合树脂，将三种单体混合物（Bis-GMA/TEGDMA、Bis-GMA/CH3 Bis-GMA和Bis-GMA/CF3 Bis-GMA）按三种稀释率（85/15、10/90、0/100）和三种混合填料含量水平（铝硅酸钡玻璃）：0%、10%和35%进行组合。评估了复合材料的弯曲强度（FS）、弹性模量（ME）和显微硬度（VHN）。每种材料制备五个试样用于每项力学测试，光固化120秒，并在37℃水中储存1周。采用三点弯曲试验测量FS，使用维氏显微压痕仪定量VHN。数据通过方差分析和Student-Newman-Keuls检验进行分析（P<0.05）。
含CH3 Bis-GMA的材料显示出增强的VHN。含TEGDMA的基质的平均FS更高。总体而言，稀释有利于FS和VHN，但对ME无影响。填料负载特别改善了ME和VHN。
结果与聚合程度的增加相关，这是由于粘度较低的共聚单体起始体系具有更高的柔韧性以及Bis-GMA类似物的疏水特性。
