Indiana University School of Dentistry, Department of Restorative Dentistry/Division of Dental Biomaterials, Indianapolis, IN 46202, USA.
Dent Mater. 2013 Nov;29(11):e281-90. doi: 10.1016/j.dental.2013.08.210. Epub 2013 Oct 3.
To evaluate the null hypotheses that hydrofluoric (HF) acid etching time would neither decrease the biaxial flexural strength of a glass-based veneering ceramic nor enhance it after silane and unfilled resin (UR) applications.
Disc-shaped IPS e.max ZirPress specimens were allocated into 12 groups: G1-control (no-etching), G2-30 s, G3-60 s, G4-90 s, G5-120 s, G6-60 s+60 s. Groups (G7-G12) were treated in the same fashion as G1-G6, but followed by silane and UR applications. Surface morphology and roughness (Ra and Rq) of the ceramics were assessed by means of scanning electron microscopy (SEM) and profilometry, respectively. Flexural strength was determined by biaxial testing. Data were analyzed by two-way ANOVA and the Sidak test (α=0.05). Weibull statistics were estimated and finite element analysis (FEA) was carried out to verify the stress concentration end areas of fracture.
The interaction (etching time vs. surface treatment) was significant for Ra (p=0.008) and Rq (0.0075). Resin-treated groups presented significantly lower Ra and Rq than non-treated groups, except for the 60s group (p<0.005). SEM revealed that etching affected the ceramic microstructure and that the UR was able to penetrate into the irregularities. A significant effect of etching time (p=0.029) on flexural strength was seen. G7-G12 presented higher strength than G1-G6 (p<0.0001). None of experimental groups failed to show 95% confidence intervals of σ0 and m overlapped. FEA showed lower stress concentration after resin treatment.
HF acid etching time did not show a damaging effect on the ceramic flexural strength. Moreover, the flexural strength could be enhanced after UR treatment.
评估零假设，即氢氟酸（HF）酸蚀时间既不会降低玻璃基贴面陶瓷的双轴弯曲强度，也不会在硅烷和未填充树脂（UR）应用后增强其强度。
将 IPS e.max ZirPress 圆盘形试件分为 12 组：G1-对照组（无蚀刻）、G2-30s、G3-60s、G4-90s、G5-120s、G6-60s+60s。G7-G12 组以与 G1-G6 相同的方式处理，但随后进行硅烷和 UR 处理。通过扫描电子显微镜（SEM）和轮廓仪分别评估陶瓷的表面形貌和粗糙度（Ra 和 Rq）。通过双轴测试确定弯曲强度。数据通过双向方差分析和 Sidak 检验（α=0.05）进行分析。估计威布尔统计数据并进行有限元分析（FEA），以验证断裂的应力集中端区域。
表面处理对 Ra（p=0.008）和 Rq（0.0075）的交互作用有显著影响。与未处理组相比，经树脂处理的组的 Ra 和 Rq 明显较低，除 60s 组外（p<0.005）。SEM 显示，蚀刻会影响陶瓷的微观结构，并且 UR 能够渗透到不规则处。蚀刻时间对弯曲强度有显著影响（p=0.029）。G7-G12 组的强度高于 G1-G6 组（p<0.0001）。实验各组均未显示置信区间σ0和 m 重叠。FEA 显示树脂处理后应力集中降低。
HF 酸蚀刻时间不会对陶瓷弯曲强度产生破坏性影响。此外，经 UR 处理后，弯曲强度可以增强。
