Objectives

To evaluate the effect of different glass-ceramic surface treatments and aging on the fatigue failure load of a lithium disilicate glass-ceramic adhesively cemented to a dentin analogue material.

Methods

One hundred and twenty (120) disc-shaped lithium disilicate specimens (Ø = 10 mm, thickness = 1.5 mm) were produced and randomly allocated (n = 20) into 6 groups, considering 2 study factors: “surface treatment” in 3 levels (SIL—silane application only; HF5+SIL—5% hydrofluoric acid etching and silane application; ME&P—etching with an one-step ceramic primer), and “storage” in 2 levels (baseline—storage for 7 days; aging—storage for 90 days + 12,000 thermal cycles). Ceramic discs were adhesively cemented to discs of a dentin analogue material (Ø = 10 mm, thickness = 2.0 mm) following the manufacturers’ instructions. The fatigue failure load was determined by the staircase approach (250,000 cycles; 20 Hz; initial load = 1050 N [∼70% of mean load-to-failure]; step size = 52.5 N [5% of initial load]). Micro-morphologic, fractographic, and atomic force microscope analysis were also performed. Fatigue failure load data were evaluated by one-way ANOVA, Bonferroni and t-tests for independent samples.

Results

HF5+SIL presented higher fatigue failure load in both conditions (baseline and aging); ME&P presented intermediary mean values, while the SIL group presented the worst performance. All groups had a statistically significant decrease in the fatigue performance after aging.

Significance

Hydrofluoric acid followed by silane application showed the best fatigue performance for an adhesively-cemented lithium disilicate ceramic. Aging negatively influenced the fatigue performance for all tested groups.

中文翻译：

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胶结二硅酸锂玻璃陶瓷的疲劳破坏载荷：常规陶瓷蚀刻与蚀刻和一次涂底漆的对比

目标

为了评估不同的玻璃陶瓷表面处理和老化对粘合到牙本质类似材料上的二硅酸锂玻璃陶瓷的疲劳破坏载荷的影响。

方法

制作了一百二十（120）个圆盘状二硅酸锂样品（Ø= 10 mm，厚度= 1.5 mm），并随机分配（n = 20）分为6组，考虑了2个研究因素：“表面处理”分为3个等级（仅SIL-硅烷应用； HF5 + SIL-5％氢氟酸蚀刻和硅烷应用； ME＆P-一步陶瓷底漆蚀刻），“存储”分为2级（基线-存储7天；老化-存储） 90天+ 12,000个热循环）。按照制造商的说明，将陶瓷圆盘粘结在牙本质类似材料（直径= 10 mm，厚度= 2.0 mm）的圆盘上。疲劳破坏负荷是通过阶梯法确定的（250,000个周期； 20 Hz；初始负荷= 1050 N [〜失效平均负荷的70％]；步长= 52.5 N [初始负荷的5％]）。微观形貌，分形，还进行了原子力显微镜分析。疲劳破坏载荷数据通过单因素方差分析，Bonferroni和t检验对独立样本进行评估。

结果

在两种情况下（基线和老化），HF5 + SIL都表现出更高的疲劳破坏负荷；ME＆P给出中间平均值，而SIL组则表现最差。所有组的衰老后疲劳表现均具有统计学上的显着下降。

意义

氢氟酸再加硅烷后，对于胶结的二硅酸锂陶瓷表现出最佳的疲劳性能。老化对所有测试组的疲劳性能均产生负面影响。