Hammoudeh Hanin, Carracho Luis, Beard Charles, Razzoog Michael
Assistant Professor, Restorative and Prosthodontics Department, The Ohio State University College of Dentistry, Columbus, Ohio; and Scholar, University of Jordan School of Dentistry, Amman, Jordan.
Assistant Professor, Department of Fixed Prosthodontics, University of Lisbon, Portugal; and Private Practice, Lisbon, Portugal.
J Prosthet Dent. 2024 Jan;131(1):164.e1-164.e11. doi: 10.1016/j.prosdent.2023.09.038. Epub 2023 Nov 8.
High translucency zirconia (HTZ) has gained popularity as an esthetic computer-aided design and computer-aided manufacturing (CAD-CAM) material for monolithic restorations. A detailed comparison between different common surface and heat treatments with a non-treated HTZ control to explain the behavior of the material under stress is lacking.
The purpose of this in vitro study was to evaluate the effect of different surface and heat treatments on the surface roughness parameters (SRPs), topography, crystallography, and phase composition of HTZ used for monolithic restorations.
Ninety Ø11.9×1.18-mm HTZ disks (Prettau Anterior) were milled, sintered, and distributed into 9 groups (n=10); 8 experimental (coarse diamond grinding GC, fine diamond grinding GF, fine diamond grinding and 3-step polishing kit GF+P1, fine diamond grinding and 3-step polishing kit and diamond paste GF+P1+DP, fine diamond grinding and 2-step polishing kit GF+P2, fine diamond grinding and GF+Gl, fine diamond grinding and 3-step polishing and glazing GF+P1+Gl, airborne-particle abrasion with 50-µm alumina), and a control group (C, as-sintered). SRPs (AveSa, AveSv, AveSz) and 3-dimensional (3D) images were obtained using a noncontact 3D-optic-profilometer. The crystal structure was determined with scanning electron microscopy. Phase composition was analyzed by X-ray diffraction (XRD). Surface roughness parameters data were statistically analyzed by 1-way ANOVA and the Tukey HSD test (α=.05).
The applied surface and heat treatment resulted in significantly different SRP mean values (P<.001) with different topographies. GC had the highest AveSa, AveSv, and AveSz mean values (0.95, 8.8, 17.4 µm, respectively) with significant microcracks. GF had significantly lower SRP with finer microcracks. GF+P1 had a significantly smoother surface, but GF+P2 resulted in SRP comparable with the GF group. GF+P1+DP had the smoothest homogenous surface (mean Sa: 0.08 µm). GF+P1 and GF+GL were equally effective, while GF+P1+GL was not superior. Airborne-particle abrasion produced a low Sa mean value (0.11 µm) with relatively high Sv and Sz mean values (5.9, 9.2 µm, respectively) and microcracks. A monoclinic phase was detected in all groups. All experimental groups had broadened XRD-peaks with lower intensity, suggesting the presence of the rhombohedral phase.
The different surface and heat treatments altered the HTZ crystals and their surface roughness with distinct topographies. Cubic crystal changes take place under stress as shown by the scanning electron microscope and the XRD diffraction pattern and may transform to the rhombohedral phase.
高透明度氧化锆（HTZ）作为一种用于整体修复的美学计算机辅助设计与制造（CAD-CAM）材料已受到广泛欢迎。目前缺乏对不同常见表面处理和热处理与未处理的HTZ对照进行详细比较，以解释该材料在应力下的行为。
本体外研究的目的是评估不同表面处理和热处理对用于整体修复的HTZ的表面粗糙度参数（SRP）、形貌、晶体学和相组成的影响。
将90个直径为11.9×1.18毫米的HTZ圆盘（Prettau Anterior）进行铣削、烧结，并分为9组（每组n = 10）；8个实验组（粗金刚石研磨GC、细金刚石研磨GF、细金刚石研磨和三步抛光套装GF + P1、细金刚石研磨和三步抛光套装及金刚石膏GF + P1 + DP、细金刚石研磨和两步抛光套装GF + P2、细金刚石研磨和GF + Gl、细金刚石研磨和三步抛光及上釉GF + P1 + Gl、50微米氧化铝空气颗粒喷砂），以及一个对照组（C，烧结态）。使用非接触式三维光学轮廓仪获取SRP（平均表面粗糙度AveSa、平均谷深AveSv、平均峰谷高度AveSz）和三维（3D）图像。通过扫描电子显微镜确定晶体结构。通过X射线衍射（XRD）分析相组成。表面粗糙度参数数据采用单因素方差分析和Tukey HSD检验进行统计学分析（α = 0.05）。
所应用的表面处理和热处理导致具有不同形貌的SRP平均值存在显著差异（P < 0.001）。GC组的AveSa、AveSv和AveSz平均值最高（分别为0.95、8.8、17.4微米），存在明显微裂纹。GF组的SRP显著较低，微裂纹更细。GF + P1组表面明显更光滑，但GF + P2组的SRP与GF组相当。GF + P1 + DP组具有最光滑的均匀表面（平均Sa：0.08微米）。GF + P1和GF + GL效果相当，而GF + P1 + GL并不更优。空气颗粒喷砂产生的平均Sa值较低（0.11微米），平均Sv和Sz值相对较高（分别为5.9、9.2微米）且存在微裂纹。所有组均检测到单斜相。所有实验组的XRD峰均变宽且强度降低，表明存在菱面体相。
不同的表面处理和热处理改变了HTZ晶体及其表面粗糙度，具有不同的形貌。如扫描电子显微镜和XRD衍射图谱所示，立方晶体在应力作用下发生变化，可能转变为菱面体相。
