Zoom Dental Clinic, Ankara, Turkey.
Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
Dent Med Probl. 2023 Jan-Mar;60(1):137-144. doi: 10.17219/dmp/149356.
The ability to simulate the natural appearance of teeth in dental restorations is one of the most important factors that make treatment successful.
The present study evaluated the effects of the substructure thickness, the resin cement color and the finishing procedure on the color and translucency of bilayer zirconia-based ceramic restorations.
Yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) CAD/CAM blocks (dimensions of 6.0 × 5.5 × 0.4 mm, 6.0 × 5.5 × 0.8 mm, and 6.0 × 5.5 × 1.6 mm) veneered with the fluorapatite-containing ceramics were used. For polishing, the surfaces of half of the test specimens were adjusted with a blue-belted diamond porcelain bur and a white polishing rubber, and the other half were glazed. The test specimens were then cemented with 2 different colors of the same self-adhesive resin cement to the resin composite. A spectrophotometer was used to measure the L*, a*, and b* color attributes of the specimens. Additionally, the ΔE values were calculated to determine color differences between each group and the control. Data was analyzed using the multifactorial repeated-measures analysis of variance (ANOVA) and subgroup analysis (p < 0.005).
It was found that the highest substructure thickness resulted in the lowest color change (ΔE = 1.24) (p < 0.005). However, a substructure thickness of 0.8 mm showed less color change (ΔE = 1.39) than the 0.4-mm thickness (ΔE = 3.85) in the translucent resin cement/polished subgroup, as measured against a gray background (p = 0.001).
The most significant factor in masking the abutment color in zirconia-based restorations is the thickness of the substructure. The surface finishing procedure or the resin cement color do not have a primary effect on the color change or translucency.
在牙体修复中，模拟牙齿自然外观的能力是治疗成功的最重要因素之一。
本研究评估了底层厚度、树脂水门汀颜色和修整程序对双层氧化锆基陶瓷修复体颜色和半透明度的影响。
使用涂有含氟磷灰石陶瓷的钇稳定四方氧化锆多晶（Y-TZP）CAD/CAM 块（尺寸为 6.0×5.5×0.4mm、6.0×5.5×0.8mm 和 6.0×5.5×1.6mm）。为了抛光，一半的试件表面用蓝色带钻石瓷牙钻和白色抛光橡胶进行调整，另一半进行上釉。然后，将试件用 2 种不同颜色的同种自粘树脂水门汀粘接到树脂复合材料上。使用分光光度计测量试件的 L*、a和 b颜色属性。此外，还计算了ΔE 值，以确定每组与对照组之间的颜色差异。使用多因素重复测量方差分析（ANOVA）和亚组分析（p<0.005）对数据进行分析。
发现底层厚度最高导致颜色变化最小（ΔE=1.24）（p<0.005）。然而，在半透明树脂水门汀/抛光亚组中，0.8mm 底层厚度的颜色变化（ΔE=1.39）小于 0.4mm 底层厚度（ΔE=3.85），与灰色背景相比（p=0.001）。
在氧化锆基修复体中掩盖基牙颜色的最重要因素是底层厚度。表面修整程序或树脂水门汀颜色对颜色变化或半透明度没有主要影响。
