Dept. of Stomatology, Maternal and Child Health Hospital of Hubei Province, Wuhan 430070, China.
Dept. of Prosthodontics, Dalian Stomatological Hospital, Dalian 116021, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2024 Feb 1;42(1):56-61. doi: 10.7518/hxkq.2024.2023263.
This study aimed to evaluate the influence of ceramic type and thickness on the masking ability and final aesthetic effects of chairside machinable all-ceramic crowns.
Six kinds from three types chairside machinable ceramic materials (IPS e.max CAD HT/MT/LT, IPS Empress LT, and VITA Suprinity HT/T) in shade A2 were fabricated to slice specimens into 1.0, 1.5, and 2.0 mm-thick sections (=10). The color parameters of the specimens against black and white tiles and four resin substrates (A2, A4, B3, and C4 shade) were measured with a spectrophotometer. The translucency parameter (TP) was calculated using color parameters measured over standard white and black backgrounds. The color differences (ΔE) were calculated between there substrate shades (A4, B3, C4 ) and A2 shade (control group). Two-way analysis of variance (ANOVA) was performed on the TP values. The two va-riables were ceramic type and ceramic thickness. Three-way ANOVA was used to determine the effects of ceramic materials, ceramic thickness, and substrate shades on the ΔE values, followed by Tukey test for multiple comparisons (α=0.05).
Ceramic type, ceramic thickness, and substrate shade significantly affected the ΔE values (<0.001). The L* and b* values of the specimens increased with increasing ceramic thickness, except in substrate A2, whereas the ΔE values decreased. The color difference of all 1.0 mm-thick specimens or all specimens over the substrates C4 shade exceeded the clinically acceptable threshold (ΔE>3.3).
The masking ability of chairside machinable all-ceramic crowns is influenced by ceramic type and thickness, and ceramic material. The thickness of ceramic less than 2.0 mm cannot mask the gray shade abutment.
本研究旨在评估陶瓷类型和厚度对椅旁加工全瓷冠的遮色能力和最终美学效果的影响。
从三种椅旁加工陶瓷材料（IPS e.max CAD HT/MT/LT、IPS Empress LT 和 VITA Suprinity HT/T）中制备 6 种 A2 色的陶瓷材料，将试件切成 1.0、1.5 和 2.0 mm 厚的切片（=10）。使用分光光度计测量试件对黑白瓷砖和 4 种树脂基底（A2、A4、B3 和 C4 色调）的颜色参数。使用标准白、黑背景下测量的颜色参数计算透光率参数（TP）。计算出各基底色调（A4、B3、C4）与 A2 色调（对照组）之间的色差（ΔE）。对 TP 值进行双因素方差分析（ANOVA）。两个变量为陶瓷类型和陶瓷厚度。采用三因素方差分析（ANOVA）确定陶瓷材料、陶瓷厚度和基底色调对 ΔE 值的影响，然后进行 Tukey 检验进行多重比较（α=0.05）。
陶瓷类型、陶瓷厚度和基底色调显著影响 ΔE 值（<0.001）。除基底 A2 外，随着陶瓷厚度的增加，试件的 L*和 b*值增加，而 ΔE 值减小。所有 1.0 mm 厚试件或所有试件在 C4 基底上的色差均超过临床可接受的阈值（ΔE>3.3）。
椅旁加工全瓷冠的遮色能力受陶瓷类型和厚度以及陶瓷材料的影响。陶瓷厚度小于 2.0 mm 不能遮盖灰色基底。
