Objective

This study investigated the influence of hydrofluoric acid (HF) etching at different concentrations on the fatigue failure load of adhesively cemented feldspathic ceramic discs (Vita Mark II). Besides, their effect on the micromorphology of ceramic surface was investigated.

Methods

Eighty ceramic discs (ϕ = 10 mm; thickness = 1.5 mm) were cemented to epoxy supporting discs (ϕ = 10 mm; thickness = 2.0 mm) using different surface conditioning methods (n = 20): nonetched control (CTRL), or etched for 60 s with different HF concentrations: 1% (HF1), 5% (HF5), or 10% (HF10). All the ceramic discs received a silane application (Monobond Plus). The epoxy discs were etched with 10% HF for 60 s and received a primer coating (Multilink Primer A + B). Adhesively cementation was performed (Multilink Automix), and the assemblies (ceramic discs/epoxy discs) were subjected to cyclic loads in water by a staircase approach (500,000 cycles; 20 Hz; initial load = 290 N; step size = 30 N). Fatigue failure load data were analyzed using 1-way ANOVA and post-hoc Tukey’s tests (α = .05).

Results

Mean failure load of the HF5 group (255.0 ± 23.0 N) was significantly lower; HF1 group (301.7 ± 71.0 N) presented intermediate values, and the highest values were achieved in CTRL (351.7 ± 13.4 N) and HF10 (341.7 ± 20.6 N) groups. All the failures were radial cracks starting from the bonding surface.

Significance

In terms of fatigue failure load, etching with 1% and 5% HF had a deleterious effect on the fatigue behavior of an adhesively cemented feldspathic ceramic, while 10% HF had no negative influence.

中文翻译：

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氢氟酸浓度对粘固长石瓷盘疲劳破坏载荷的影响

客观的

这项研究调查了不同浓度的氢氟酸（HF）蚀刻对粘固长石瓷盘（Vita Mark II）的疲劳破坏载荷的影响。此外，研究了它们对陶瓷表面微观形貌的影响。

方法

 使用不同的表面处理方法（n = 20）将80个陶瓷圆盘（φ  = 10 mm;厚度= 1.5 mm）粘结到环氧支撑盘（φ = 10 mm;厚度= 2.0 mm）：非蚀刻控制（CTRL）或蚀刻在60 s内使用不同的HF浓度：1％（HF1），5％（HF5）或10％（HF10）。所有的陶瓷圆盘都接受了硅烷应用（Monobond Plus）。用10％HF蚀刻环氧盘60秒钟，并接受底漆涂层（Multilink Primer A + B）。进行粘合胶结（Multilink Automix），然后通过阶梯法（500,000个循环； 20 Hz；初始载荷= 290 N；步长= 30 N）在水中对组件（陶瓷盘/环氧树脂盘）施加循环载荷。使用1向ANOVA和事后Tukey测试对疲劳破坏载荷数据进行了分析（α  = 0.05）。

结果

HF5组的平均故障负荷（255.0±23.0 N）显着降低；HF1组（301.7±71.0 N）呈现中间值，而CTRL（351.7±13.4 N）和HF10（341.7±20.6 N）组达到最高值。所有的故障都是从粘结表面开始的径向裂纹。

意义

就疲劳破坏载荷而言，用1％和5％的HF进行蚀刻对粘固长石陶瓷的疲劳行为具有有害影响，而10％HF则无不利影响。