3种可切削树脂陶瓷复合材料机械性能比较

目的:采用体外研究方法 ,比较3种可切削树脂陶瓷复合材料的挠曲性能、断裂韧性及硬度。方法 :选择UpceraHyramic、3M Lava Ultimate、Vita Enamic和对照组玻璃陶瓷Vitablocs MarkⅡ,分别制作成长、宽、高为16 mm×4 mm×1.0 mm、2.0 mm的挠曲强度实验试件,17 mm×4 mm×3 mm的断裂韧性实验试件和厚度为4 mm的硬度实验试件。应用万能实验机以0.5 mm/min的加载速度,测量并计算试件挠曲强度值和断裂韧性值;应用显微硬度仪测量并计算硬度值;扫描电镜观察试件断面粗糙程度。采用SPSS17.0软件包对实验数据进行单因素方差分析。结果:厚度1 mm时,各组挠曲强度值为Hyramic(207.7515±13.12) MPa>Vita Enamic(182.0286±15.18)MPa>Lava Ultimate(145.8469±8.98)MPa>Vitablocs MarkⅡ(103.0542±18.19)MPa;挠曲模量为Vitablocs MarkⅡ(49.49±5.50)GPa>Vita Enamic(40.65±3.80)GPa>Hyramic (14.89±2.38)GPa>Lava Ultimate (7.09±1.24)GPa。厚度2 mm时,各组挠曲强度值为Hyramic (208.1986±25.07)MPa>Lava Ultimate (172.9297±12.73) MPa>Vitablocs MarkⅡ(158.6587±15.37)MPa>VitaEnamic(155.3670±13.77)MPa;挠曲模量为Vitablocs MarkⅡ(24.07±1.86)GPa>Vita Enamic(19.64±0.98)GPa>Hyramic(10.35±0.87)GPa>Lava Ultimate (8.68±0.86)GPa。断裂韧性为Vita Enamic (1.6357±0.16)MPa·m^1/2>Lava Ultimate(1.4286±0.11)MPa·m^1/2>Vitablocs MarkⅡ(1.3233±0.10)MPa·m^1/2>Hyramic(1.0614±0.09) MPa·m^1/2。各实验组硬度均显著低于对照组。结论:根据ISO 6872/2008,3种可切削树脂陶瓷复合材料均满足临床强度需要。其中,Hyramic在不同厚度条件下都表现出了较高的挠曲强度,是比较理想的后牙修复材料;而Vita Enamic在1 mm时具有更高的机械强度,且韧性好,适用于后牙咬合空间有限且咬合力较大的患者的修复,即(牙合)贴面。

Comparison of mechanical properties of three machinable resin ceramic composite materials

PURPOSE: This in vitro study was to compare the flexural properties, fracture toughness and hardness of three machinable composite materials. METHODS: Three kinds of resin composite ceramic Upcera Hyramic, 3M Lava Ultimate, Vita Enamic and a glass ceramic Vitablocs Mark II were chosen for the study. Bar-shaped specimens (16 mm×4 mm×1 mm, 2 mm) were prepared for flexural strength experiment; specimens (17 mm×4 mm×3 mm) were prepared for fracture toughness experiment and specimens of 4 mm thickness were prepared for hardness test. Flexural test and fracture toughness experiment were performed with an universal testing machine at a cross-head speed of 0.5 mm/min. Hardness test was performed with an micro hardness tester .Scanning electron microscope was used to observe the roughness of fracture surface. One-way variance analysis was used to determine the statistical differences with SPSS 17.0 software package. RESULTS: The mean flexural strength of the tested blocks at 1 mm thickness was Hyramic（207.7515±13.12）MPa>Vita Enamic（182.0286±15.18）MPa>Lava Ultimate（145.8469±8.98）MPa>Vitablocs MarkⅡ（103.0542±18.19）MPa. The mean flexural modulus were Vitablocs MarkⅡ（49.49±5.50）GPa>Vita Enamic（40.65±3.80）GPa>Hyramic（14.89±2.38）GPa>Lava Ultimate（7.09±1.24）GPa. The mean flexural strength of the tested blocks at 2 mm thickness was Hyramic（208.1986±25.07）MPa>Lava Ultimate（172.9297±12.73）MPa>Vitablocs MarkⅡ（158.6587±15.37） MPa>Vita Enamic（155.3670±13.77）MPa. The mean flexural modulus were Vitablocs MarkⅡ（24.07±1.86）GPa>Vita Enamic（19.64±0.98）GPa>Hyramic（10.35±0.87）GPa>Lava Ultimate（8.68±0.86）GPa. The mean fracture toughness was Vita Enamic（1.6357±0.16）MPa·m^1/2>Lava Ultimate（1.4286±0.11）MPa·m^1/2>Vitablocs MarkII（1.3233±0.10）MPa·m^1/2>Hyramic（1.0614±0.09）MPa·m^1/2. The hardness of the experimental group was significantly lower than that of the control group. CONCLUSIONS: According to ISO 6872/2008, three kinds of machinable resin ceramic composites meet the needs of clinical strength.Hyramic showed higher flexural strength at different thickness, it is an ideal material for dental restoration. Vita Enamic has not only higher flexural strength at the thickness of 1 mm, but also good toughness, it is suitable for repair of patients that have limited occlusal space and great bite force, named occlusal veneer.