Investigation of Mechanical Properties of Experimental Bis-GMA/TEGDMA Dental Composite Resins Containing Various Mass Fractions of Silica Nanoparticles
Investigation of Mechanical Properties of Experimental Bis-GMA/TEGDMA Dental Composite Resins Containing Various Mass Fractions of Silica Nanoparticles
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DOI：
10.1111/j.1532-849x.2009.00530.x
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发表时间：
2010-02-01
影响因子：
4
通讯作者：
Hayati, Amir Nemati
中科院分区：
文献类型：
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作者：
Hosseinalipour, Mohammad;Javadpour, Jafar;Hayati, Amir Nemati
目的：牙科复合树脂的力学性能有待提高，以提高其在直接修复中的应用性能。纳米粒子在这一领域的应用是最近的发展。本研究的目的是研究含有不同质量分数的二氧化硅纳米颗粒的实验复合材料的力学性能。材料和方法：实验复合材料由可见光固化的单体混合物(70wt%Bis-GMA和30wt%TEGDMA)和粒径为20~50 nm的二氧化硅纳米颗粒组成，并以伽马-甲基丙烯氧基丙基三甲氧基硅烷(Gamma-MPS)为增强填料。根据填料质量分数从20%到50%的不同，将复合材料分为四组。按照相同的制备工艺，在相同的有机基质中制备了质量分数为60%、粒径在10~40µm之间的二氧化硅作为对照的复合材料。每个实验组和对照组各10个标本。断裂韧性测量采用单边缺口弯曲(SENB)试件。试件断口表面用碳粘结剂安装在铝桩上，溅射镀金，并在扫描电子显微镜(SEM)下观察。通过标准的三点弯曲试验和维氏显微硬度试验测试了复合材料的抗弯强度。结果：填料质量分数对复合材料的性能有显著影响。当纳米二氧化硅质量分数为40%时，复合材料的断裂韧性、弯曲强度和硬度分别为(平均值+/-SD)1.43+/-0.08MPAm(1/2)、149.74+/-8.14 Mpa和62.12+/-3.07VHN；在二氧化硅纳米粒子质量分数为50%时，复合材料的相关值分别为1.38+/-0.07MPAM(1/2)、122.83+/-6.13 Mpa和70.69+/-3.67VHN，均显著高于对照组的1.07+/-0.06MPAM(1/2)、104.61+/-8.73 Mpa和52.14+/-4.02VHN(图基多重比较检验；家庭可信系数=0.95)。纳米二氧化硅质量分数为20%时，复合材料的测量值分别为0.94+/-0.06MPAM(1/2)、103.41+/-7.62 Mpa和42.87+/-2.61VHN；在纳米二氧化硅质量分数为30%时，复合材料的相关数值分别为1.16+/-0.07MPAM(1/2)、127.91+/-7.05 Mpa和51.78+/-3.41VHN。结论：纳米二氧化硅增强牙科复合树脂的综合力学性能较传统复合材料有显著提高。填料的质量分数对复合材料的力学性能起着至关重要的作用。
Purpose: Mechanical properties of dental composite resins need to be improved in order to enhance their performance for applications in direct restorations. Application of nanoparticles in this field is a recent development. The aim of this study was to investigate the mechanical properties of experimental composites containing various mass fractions of silica nanoparticles.Materials and Methods: Experimental composites were composed of a visible-light-curing monomer mixture (70 wt% Bis-GMA and 30 wt% TEGDMA) and silica nanoparticles of a size ranging from 20 nm to 50 nm modified with gamma-methacryloxy propyl trimethoxy silane (gamma-MPS) as reinforcing filler. The composites were classified into four groups according to their filler mass fractions ranging from 20% to 50%. Following the same preparation procedure, a conventional composite was also fabricated consisting of a mass percentage of 60% silica fillers having particle sizes ranging from 10 mu m to 40 mu m in the same organic matrix, which served as control. Ten specimens were prepared of each experimental group and also of the control. Fracture toughness was measured using single-edge notched bend (SENB) specimens. Specimen fracture surfaces were mounted on aluminum stubs with carbon cement, sputter-coated with gold and examined under scanning electron microscopy (SEM). Flexural strength was evaluated through a standard three-point bending test and Vickers microhardness test was performed to investigate the hardness of the samples.Results: Filler mass fraction had a significant effect on composite properties. Fracture toughness, flexural strength, and hardness of composites at filler mass fraction of 40% of silica nanoparticles were (mean +/- SD) 1.43 +/- 0.08 MPa.m(1/2), 149.74 +/- 8.14 MPa, and 62.12 +/- 3.07 VHN, respectively; relevant values for composites at 50% mass fraction of silica nanoparticles were 1.38 +/- 0.07 MPa.m(1/2), 122.83 +/- 6.13 MPa, and 70.69 +/- 3.67 VHN, respectively, all of which were significantly higher than 1.07 +/- 0.06 MPa.m(1/2), 104.61 +/- 8.73 MPa, and 52.14 +/- 4.02 VHN of the control, respectively (Tukey's multiple comparison test; family confidence coefficient = 0.95). Measured values for composites at 20% mass fraction of silica nanoparticles were 0.94 +/- 0.06 MPa.m(1/2), 103.41 +/- 7.62 MPa, and 42.87 +/- 2.61 VHN, respectively; relevant values for composites at 30% mass fraction of silica nanoparticles were 1.16 +/- 0.07 MPa.m(1/2), 127.91 +/- 7.05 MPa, and 51.78 +/- 3.41 VHN, respectively.Conclusions: Reinforcement of dental composite resins with silica nanoparticles resulted in a significant increase in the evaluated mechanical properties in comparison with the conventional composite. The filler mass fraction played a critical role in determining the composite's mechanical properties.