Department of Prosthodontics, Universidade Federal de Santa Catarina, Florianopolis, Brazil.
J Adhes Dent. 2010 Aug;12(4):311-7. doi: 10.3290/j.jad.a17710.
To test the strength to failure and fracture mode of three indirect composite materials directly applied onto Ti-6Al-4V implant abutments vs cemented standard porcelain-fused-to-metal (PFM) crowns.
Sixty-four locking taper abutments were randomly allocated to four groups and were cleaned in ethanol in an ultrasonic bath for 5 min. After drying under ambient conditions, the abutments were grit blasted and a custom 4-cusp molar crown mold was utilized to produce identical crowns (n = 16 per group) of Tescera (Bisco), Ceramage (Shofu), and Diamond Crown (DRM) according to the manufacturer's instructions. The porcelain-fused-to-metal crowns were fabricated by conventional means involving the construction and a wax pattern and casting of a metallic coping followed by sintering of increasing layers of porcelain. All crowns were loaded to failure by an indenter placed at one of the cusp tips at a 1 mm/min rate. Subsequently, fracture analysis was performed by means of stereomicroscopy and scanning electron microscopy. One-way ANOVA at 95% level of significance was utilized for statistical analysis.
The single load to failure (± SD) results were: Tescera (1130 ± 239 N), Ceramage (1099 ± 257 N), Diamond Crown (1155 ± 284 N), and PFM (1081 ± 243 N). Stereomicroscopy analysis showed two distinct failure modes, where the loaded cusp failed either with or without abutment/metallic coping exposure. SEM analysis of the fractures showed multiple crack propagation towards the cervical region of the crown below a region of plastic deformation at the indenter contact region.
The three indirect composites and PFM systems fractured at loads higher than those typically associated with normal occlusal function. Although each material had a different composition and handling technique, no significant differences were found concerning their single load to fracture resistance among composite systems and PFM.
测试直接应用于 Ti-6Al-4V 种植体基台的三种间接复合树脂材料的断裂强度和断裂模式与粘结标准烤瓷金（PFM）冠的比较。
将 64 个锁定锥形基台随机分配到四组，并用乙醇在超声浴中清洗 5 分钟。在环境条件下干燥后，用喷砂对基台进行喷砂处理，并使用定制的 4 尖磨牙冠模具，根据制造商的说明，生产出相同的 Tescera（Bisco）、 Ceramage（Shofu）和 Diamond Crown（DRM）冠（每组 16 个）。PFM 冠通过传统方法制造，涉及构建蜡型和铸造金属冠，然后进行多层瓷的烧结。所有的牙冠都在一个牙尖处以 1mm/min 的速率加载至失效。随后，通过立体显微镜和扫描电子显微镜进行断裂分析。使用单向方差分析（95%置信水平）进行统计分析。
单载断裂（±SD）结果为：Tescera（1130±239N）、 Ceramage（1099±257N）、Diamond Crown（1155±284N）和 PFM（1081±243N）。立体显微镜分析显示了两种明显的失效模式，加载的牙尖要么与基台/金属冠一起失效，要么不与基台/金属冠一起失效。对断裂的扫描电镜分析显示，在压痕接触区域的塑性变形下方的冠的颈部区域有多个裂纹扩展。
三种间接复合树脂和 PFM 系统在高于正常咬合功能相关的负载下断裂。尽管每种材料的组成和处理技术不同，但在复合系统和 PFM 之间，其单一断裂阻力的负载没有显著差异。
