Xu H H, Smith D T, Schumacher G E, Eichmiller F C, Antonucci J M
Paffenbarger Research Center, American Dental Association Health Foundation, National Institute of Standards and Technology, Gaithersburg, MD 20899-8546, USA.
Dent Mater. 2000 Jul;16(4):248-54. doi: 10.1016/s0109-5641(00)00014-2.
Recent studies showed that ceramic whisker reinforcement imparted a two-fold increase in the strength of dental composites. The aim of this study was to investigate the indentation response and measure the elastic modulus, hardness, and brittleness of whisker-reinforced heat-cured resin composites as a function of filler level, heat-cure temperature, and heat-cure duration.
Silica particles were fused onto silicon nitride whiskers to facilitate silanization and to roughen the whiskers for improved retention in matrix. Whisker filler mass fractions of 0, 20, 40, 60, 70, 74 and 79% were tested. Heat-cure temperature ranged from 100 to 180 degrees C, and duration from 10 min to 24 h. A nano-indentation system enabled the measurement of elastic modulus. Fracture toughness was measured and composite brittleness index was calculated. An inlay/onlay composite and a prosthetic composite were tested as controls.
Whisker filler level and heat-cure duration had significant effects on composite properties, while heat-cure temperature had non-significant effects. The whisker composite with 79% filler level had a modulus in GPa (mean (SD); n = 6) of 26.9 (1.0), significantly higher than 15.1 (0.2) of an inlay/onlay control, and 16.1 (0.3) of a prosthetic control (Tukey's multiple comparison test; family confidence coefficient = 0.95). The fracture toughness in MPa.m1/2 was 2.22 (0.26) for the whisker composite, higher than 0.95 (0.11) for inlay/onlay control, and (1.13 +/- 0.19) for prosthetic control. The brittleness index was (0.49 +/- 0.07) for whisker composite, lower than (1.02 +/- 0.12) for inlay/onlay control and (0.63 +/- 0.13) for prosthetic control.
Whisker filler level had a profound influence, heat-cure duration had significant effects, while temperature did not have significant effects, on the properties of whisker composite. The whisker composite had significantly higher elastic modulus and fracture toughness, and lower brittleness than the inlay/onlay and prosthetic controls.
近期研究表明，陶瓷晶须增强可使牙科复合材料的强度提高两倍。本研究的目的是研究晶须增强热固化树脂复合材料的压痕响应，并测量其弹性模量、硬度和脆性，作为填料含量、热固化温度和热固化时间的函数。
将二氧化硅颗粒熔合到氮化硅晶须上，以促进硅烷化并使晶须表面粗糙化，从而提高其在基体中的保留率。测试了晶须填料质量分数为0、20、40、60、70、74和79%的情况。热固化温度范围为100至180摄氏度，时间为10分钟至24小时。使用纳米压痕系统测量弹性模量。测量断裂韧性并计算复合材料脆性指数。测试了嵌体/高嵌体复合材料和修复复合材料作为对照。
晶须填料含量和热固化时间对复合材料性能有显著影响，而热固化温度影响不显著。填料含量为79%的晶须复合材料的弹性模量（单位：GPa；平均值（标准差）；n = 6）为26.9（1.0），显著高于嵌体/高嵌体对照的15.1（0.2）和修复对照的16.1（0.3）（Tukey多重比较检验；族置信系数 = 0.95）。晶须复合材料的断裂韧性（单位：MPa·m1/2）为2.22（0.26），高于嵌体/高嵌体对照的0.95（0.11）和修复对照的（1.13±0.19）。晶须复合材料的脆性指数为（0.49±0.07），低于嵌体/高嵌体对照的（1.02±0.12）和修复对照的（0.63±0.13）。
晶须填料含量对晶须复合材料的性能有深远影响，热固化时间有显著影响，而温度无显著影响。与嵌体/高嵌体和修复对照相比，晶须复合材料具有显著更高的弹性模量和断裂韧性，以及更低的脆性。
