Objective

The aim of the present study was to assess the effect of water storage on the quasi-static properties and cyclic fatigue behavior of four contemporary CAD/CAM resin composite materials.

Methods

The CAD/CAM resin composites Grandio Blocs, Lava^TM Ultimate, Cerasmart^TM and Brilliant Crios, as well as the direct resin composite Grandio SO, were evaluated. Rectangular plates were cut from the blocks or fabricated using a silicon mold to obtain specimens for fracture toughness (K_Ic, n = 10), biaxial strength (σ₀, n = 30) and cyclic fatigue testing (n = 30). Half of the specimens was stored for 24 h in dry conditions and the other half was aged for 60 days in distilled water at 37 °C. K_Ic was determined using the Compact-Tension (C(T)) method and σ₀ and cyclic fatigue were tested using the Ball-on-Three-Balls assembly. Additional disc-shaped specimens (n = 5) were produced to obtain water sorption curves of the materials. Weibull statistics and two-way ANOVA with Tukey’s post-hoc test were used for data assessment.

Results

The highest water sorption was observed for Lava^TM Ultimate (42.6 μg/mm³), whereas Grandio SO displayed the lowest uptake (14 μg/mm³). A statistically significant drop in K_Ic and σ₀ was measured for all materials after water storage, except for the σ₀ of Cerasmart^TM. Water ageing had a dissimilar effect on the cyclic fatigue behavior, increasing the slow crack growth susceptibility of Lava^TM Ultimate, but decreasing it for Cerasmart^TM and Brilliant Crios.

Significance

Contemporary CAD/CAM resin composites are susceptible to water driven degradative processes, although differences in filler content and resin matrix constitution play an important role in how it impacts their mechanical properties.

中文翻译：

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当代CAD/CAM树脂复合材料水老化后的机械降解

客观的

本研究的目的是评估储水对四种当代 CAD/CAM 树脂复合材料的准静态性能和循环疲劳行为的影响。

方法

评估了CAD/CAM 树脂复合材料 Grandio Blocs、Lava ^TM Ultimate、Cerasmart ^TM和 Brilliant Crios，以及直接树脂复合材料 Grandio SO。从块上切下矩形板或使用硅模具制造以获得断裂韧性 ( K _Ic , n = 10)、双轴强度 ( σ ₀ , n = 30) 和循环疲劳测试 (n = 30) 的试样。一半的样品在干燥条件下储存 24 小时，另一半在 37°C 的蒸馏水中老化 60 天。K _Ic是使用紧致张力 (C(T)) 方法和σ _{0 确定的}和循环疲劳使用球对三球组件进行测试。生产额外的圆盘状试样 (n = 5) 以获得材料的吸水曲线。Weibull 统计量和带有 Tukey 事后检验的双向方差分析用于数据评估。

结果

Lava ^TM Ultimate 的吸水率最高（42.6 μg/mm ³），而 Grandio SO 的吸水率最低（14 μg/mm ³）。除了Cerasmart ^TM的σ ₀外，所有材料在储水后的K _Ic和σ ₀都有统计学显着下降。水老化对循环疲劳行为有不同的影响，增加了 Lava ^TM Ultimate的缓慢裂纹扩展敏感性，但降低了 Cerasmart ^TM和 Brilliant Crios 的敏感性。

意义

现代 CAD/CAM 树脂复合材料易受水驱动的降解过程的影响，尽管填料含量和树脂基体构成的差异在影响其机械性能方面起着重要作用。