Bond and topography evaluation of a Y-TZP ceramic with a superficial low-fusing porcelain glass layer after different hydrofluoric acid etching protocols

Abstract Introduction Despite being one of the most studied ceramics today, zirconia still does not have a well-defined adhesion protocol. Objective Evaluate the influence of different etching times and hydrofluoric acid (HF) concentrations on the zirconia surface and bond strength between a vitrified Y-TZP ceramic and a resin cement. Materials and method The zirconia surface treatments were: sandblasting with silica-coated alumina (Co); glaze application + 5% HF etching for 5s (G5-5s), 10s (G5-10s) or 20s (G5-20s); glaze application + 10% HF etching for 5s (G10-5s), 10 (G10-10s) or 20s (G10-20s) . Then, cement cylinders (3.3 × 3.3 mm) were built up for shear bond test on all specimens. The specimens were subjected to 6000 thermal cycling before the test. Fractures were analyzed by stereomicroscope. Data were statistically analyzed by Kruskal-Wallis and Dunn statistical tests (5%). Extra samples of each group were made to obtain profilometry and scanning electron microscopy (SEM). Result Zirconia-cement bond strength was affected by the ceramic surface treatments (p = 0.001). G10-5s (2.71 MPa) recorded the highest bond strength values, followed by the Co (2.05 MPa) while G5 groups had the lowest bond value. Adhesive failure of the samples predominated. The image analysis revealed G5 groups seem to have a lower roughness when compared to groups treated by 10% HF. The creation of pores in the low-fusing porcelain glass layer surface occurred only when 10% HF was used. Conclusion The low-fusing porcelain glass layer application was able to overcome the sandblasting and obtain a greater adhesive bond to the resinous cement, however, only when 10% HF was used for an interval of 5 seconds.

摘要 尽管氧化锆是当前研究最为广泛的陶瓷材料之一，但其尚未形成规范统一的粘接工艺规程。目的 评估不同蚀刻时长与氢氟酸（hydrofluoric acid, HF）浓度对氧化锆表面的影响，以及玻璃化Y-TZP陶瓷（vitrified Y-TZP ceramic）与树脂水门汀之间的粘接强度。材料与方法 氧化锆表面处理方式如下：硅涂层氧化铝喷砂（Co组）；涂釉+5%氢氟酸蚀刻5秒（G5-5s组）、10秒（G5-10s组）或20秒（G5-20s组）；涂釉+10%氢氟酸蚀刻5秒（G10-5s组）、10秒（G10-10s组）或20秒（G10-20s组）。随后于所有试件上制备尺寸为3.3×3.3 mm的水门汀圆柱试样，以开展剪切粘接强度测试。试件于测试前接受6000次热循环处理。采用体视显微镜对断裂模式进行分析。数据采用Kruskal-Wallis检验与Dunn检验进行统计学分析（检验水准α=0.05）。另制备每组的额外试件，用于表面轮廓测量与扫描电子显微镜（scanning electron microscopy, SEM）观察。结果 氧化锆与水门汀的粘接强度受陶瓷表面处理方式的影响（p=0.001）。其中G10-5s组粘接强度最高，为2.71 MPa，其次为Co组（2.05 MPa），G5组的粘接强度最低。试件以粘接破坏模式为主。图像分析结果显示，与10%氢氟酸蚀刻组相比，G5组表面粗糙度更低。仅在使用10%氢氟酸蚀刻时，低熔瓷玻璃层表面才会形成孔隙。结论 涂覆低熔瓷玻璃层可弥补喷砂处理的不足，实现与树脂水门汀更强的粘接结合，但该效果仅在采用10%氢氟酸蚀刻5秒时方可实现。