Venturini Andressa B, Prochnow Catina, May Liliana G, Bottino Marco C, Felipe Valandro Luiz
Prosthodontics Unit, School of Dentistry, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
Department of Restorative Dentistry (Division of Dental Biomaterials), Indiana University School of Dentistry, Indianapolis, IN, USA.
J Mech Behav Biomed Mater. 2015 Aug;48:241-248. doi: 10.1016/j.jmbbm.2015.03.025. Epub 2015 Apr 3.
This study evaluated the effects of etching with increasing hydrofluoric (HF) acid concentrations on the roughness and flexural strength of a feldspathic ceramic. One hundred and fifty ceramic specimens (14×4×1.2 mm(2)) were produced from ceramic blocks (VitaBlocks Mark II). All specimens were polished, chamfered and sonically cleaned in isopropyl alcohol. Specimens were randomly divided into 5 groups (n=30): SC (control) no ceramic surface etching; HF1, HF3, HF5 and HF10 ceramic surface etching for 60s with 1%, 3%, 5% and 10% HF acid concentrations, respectively. Profilometry was performed in all specimens to evaluate roughness prior to flexural strength testing. Data were analyzed using one-way ANOVA and Tukey׳s test (α=0.05). Weibull module (m) and characteristic stress (σc) were also determined. HF acid etching, regardless of the concentration used, led to significantly rougher surfaces than the control (p<0.05). However, the mean flexural strength values were not statistically different among the etched groups (106.47 to 102.02 MPa). Acid etching significantly reduced the mean flexural strength when compared with the control (143.3 MPa). Weibull modulus of the groups was similar, except for the HF5 group that was higher compared to HF3. Flexural strength was similarly affected by the different HF acid concentrations tested, but roughness increased higher the acid concentration. Ceramic etching led to a significant reduction in strength when compared to the untreated ceramic, regardless of its concentration.
本研究评估了使用浓度递增的氢氟酸（HF）蚀刻对长石质陶瓷粗糙度和抗弯强度的影响。从陶瓷块（VitaBlocks Mark II）制作了150个陶瓷试样（14×4×1.2 mm²）。所有试样均进行抛光、倒角并在异丙醇中超声清洗。试样随机分为5组（n = 30）：SC（对照组）不进行陶瓷表面蚀刻；HF1、HF3、HF5和HF10组分别用1%、3%、5%和10%的HF酸浓度对陶瓷表面蚀刻60秒。在所有试样上进行轮廓测定以在抗弯强度测试前评估粗糙度。使用单因素方差分析和Tukey检验（α = 0.05）分析数据。还确定了威布尔模量（m）和特征应力（σc）。无论使用何种浓度的HF酸蚀刻，均导致表面粗糙度显著高于对照组（p < 0.05）。然而，蚀刻组之间的平均抗弯强度值无统计学差异（106.47至102.02 MPa）。与对照组（143.3 MPa）相比，酸蚀刻显著降低了平均抗弯强度。除HF5组高于HF3组外，各组的威布尔模量相似。不同测试HF酸浓度对抗弯强度的影响相似，但酸浓度越高粗糙度增加越高。与未处理的陶瓷相比，无论其浓度如何，陶瓷蚀刻均导致强度显著降低。
