J Adhes Dent. 2021 Dec 3;23(6):579-587. doi: 10.3290/j.jad.b2287769.
To evaluate the effect of different HF-etching protocols on the dissolution depth and micromorphology of the etched and adjacent surfaces of ultrathin glass-ceramic specimens.
One hundred twenty specimens (6 x 6 x 0.3 mm) of leucite-reinforced glass-ceramic (LEU, IPS Empress, Ivoclar Vivadent) and lithium-disilicate-reinforced glass-ceramic (LD, IPS e.max, Ivoclar Vivadent) were prepared. Specimens were divided into 5 groups (n = 12) according to etching protocol: G1: control, untreated; G2: 5% hydrofluoric acid (HF) etching for 20 s (HF5%20s); G3: HF5%60s; G4: HF10%20s; and G5: HF10%60s. To analyze the dissolution depth, specimens were sectioned into two similarly sized halves using a chisel to create an internal surface (IS). Specimens were analyzed with scanning electron microscopy (SEM) on the following surfaces: HF application surface (AS), lateral surface (LS), internal surface (IS), and the surface opposite to the AS (OS). Dissolution patterns were identified. Data were submitted to one-way ANOVA and Bonferroni's test (α = 0.05). Dissolution depth data were submitted to Kruskal-Wallis and Mann-Whitney U-tests (α = 0.05). The prevalence of different dissolution patterns was analyzed using SEM.
HF gel applied on the AS also affected the adjacent surfaces of all specimens. Different dissolution patterns were observed, which were dependent of HF-etching protocol and proportion of the glass phase in the ceramic. These patterns were categorized into four types for LEU (I-IV) and three for LD (I-III) according to the micropore size. The greater the micropore size, the more pronounced the etching pattern (p < 0.001). Higher HF times and concentrations showed prevalence of more severe etching patterns. HF10%60s produced greater dissolution depth in both materials when compared with other HF-etching groups (p < 0.05).
Hydrofluoric acid etching not only affects the surface upon which it is applied, but internal, lateral and even opposite edges of glass ceramic. Different dissolution patterns and depths can be formed which are dependent of hydrofluoric acid concentration, application time, and proportion of the glass phase in the ceramic.
评估不同 HF 蚀刻方案对超薄玻璃陶瓷试件蚀刻和相邻表面的溶解深度和微观形态的影响。
制备 120 个（6x6x0.3mm）透锂长石增强玻璃陶瓷（LEU，IPS Empress，Ivoclar Vivadent）和锂硅增强玻璃陶瓷（LD，IPS e.max，Ivoclar Vivadent）试件。根据蚀刻方案将试件分为 5 组（n=12）：G1：对照，未处理；G2：5%氢氟酸（HF）蚀刻 20 秒（HF5%20s）；G3：HF5%60s；G4：HF10%20s；G5：HF10%60s。为了分析溶解深度，使用凿子将试件切成两半，在内部表面（IS）上创建一个内部表面。用扫描电子显微镜（SEM）分析试件在以下表面的情况：HF 应用表面（AS）、侧表面（LS）、内部表面（IS）和与 AS 相对的表面（OS）。确定溶解模式。将数据提交给单因素方差分析和 Bonferroni 检验（α=0.05）。将溶解深度数据提交给 Kruskal-Wallis 和 Mann-Whitney U 检验（α=0.05）。使用 SEM 分析不同溶解模式的发生率。
应用于 AS 的 HF 凝胶也会影响所有试件的相邻表面。观察到不同的溶解模式，这些模式取决于 HF 蚀刻方案和陶瓷中玻璃相的比例。根据微孔尺寸，将这些模式分类为 LEU（I-IV）的四种类型和 LD（I-III）的三种类型。微孔尺寸越大，蚀刻模式越明显（p<0.001）。较高的 HF 时间和浓度显示出更严重的蚀刻模式的普遍性。与其他 HF 蚀刻组相比，HF10%60s 在两种材料中产生了更大的溶解深度（p<0.05）。
氢氟酸蚀刻不仅影响其应用的表面，还影响内部、侧面甚至陶瓷的相对边缘。可以形成不同的溶解模式和深度，这取决于氢氟酸浓度、应用时间和陶瓷中玻璃相的比例。
