Int J Oral Maxillofac Implants. 2020 Mar/Apr;35(2):357-365. doi: 10.11607/jomi.7731.
Different titanium bases for implant-supported prostheses can present different mechanical behavior. The goal of this study was to evaluate the torque before and after fatigue, the load to failure, and stress concentration of zirconia restorations cemented or notched to a titanium base.
Forty implants were included in polyurethane cylinders and divided into two groups: zirconia restoration cemented on a titanium base and zirconia restoration notched on a titanium base. The specimens had their torque loosening and vertical misfit evaluated before and after cyclic fatigue (200 N/2 Hz/2 × 10 cycles/37°C). Load to failure was evaluated in a universal testing machine (1 mm/min, 1,000 kgf). Failures were evaluated by scanning electron microscopy. Three-dimensional models were created, and the stress concentration was calculated using the finite element method. Data from the in vitro tests were submitted to two-way analysis of variance and Tukey test (α = .5).
The cemented restorations presented less torque loosening (19.79 to 15.95 Ncm), lower vertical misfit (3.7 to 10.5 μm), lower stress concentration in the restoration (88.2 to 99.8 MPa), and higher fracture load (451.3 to 390.8 N) than notched restorations.
The presence of a cement layer between the restoration and titanium base reduced the susceptibility to abutment screw loosening, improved the resistance to compressive load, and reduced the stress concentration in the restoration.
不同的钛基底用于种植体支持的修复体可能具有不同的机械性能。本研究的目的是评估疲劳前后的扭矩、破坏载荷和未开槽或开槽氧化锆修复体粘结到钛基底后的应力集中。
将 40 个种植体纳入聚亚安酯圆柱体中，并分为两组：粘结在钛基底上的氧化锆修复体和开槽在钛基底上的氧化锆修复体。评估试件在循环疲劳（200 N/2 Hz/2×10 次/37°C）前后的扭矩松动和垂直不匹配。在万能试验机上评估破坏载荷（1mm/min，1000kgf）。通过扫描电子显微镜评估失效。创建三维模型，并使用有限元法计算应力集中。体外测试数据采用双向方差分析和 Tukey 检验（α=0.5）。
粘结修复体的扭矩松动较小（19.79 至 15.95 Ncm），垂直不匹配较小（3.7 至 10.5μm），修复体的应力集中较低（88.2 至 99.8 MPa），破坏载荷较高（451.3 至 390.8 N）。
修复体和钛基底之间存在粘结层降低了基台螺丝松动的易感性，提高了抗压载荷的抵抗力，并降低了修复体的应力集中。
