Assistant Professor, Department of Prosthodontics, Istanbul Aydin University Faculty of Dentistry, Istanbul, Turkey.
Former Visiting Professor, Division of Restorative Sciences and Prosthodontics, College of Dentistry, The Ohio State University; Assistant Professor, Department of Prosthodontics, Okan University Faculty of Dentistry, Istanbul, Turkey.
J Prosthet Dent. 2018 Oct;120(4):603-608. doi: 10.1016/j.prosdent.2018.01.018. Epub 2018 May 25.
The color stability and translucency of preshaded and externally shaded monolithic and veneered new generation translucent zirconia are not well known.
The purpose of this in vitro study was to investigate the effect of fabrication (veneered or monolithic) and shading (preshaded or externally shaded) techniques on the color and relative translucency of translucent zirconia after coffee thermocycling.
Specimens of different thicknesses (0.5 mm for veneered and 1.5 mm for monolithic) were sectioned from preshaded and externally shaded translucent zirconia. Externally shaded specimens were colored by using the dipping technique. Externally shaded (Ext Mono) and preshaded (Pre Mono) monolithic zirconia specimens were sintered and glazed. Externally shaded (Ext Vene) and preshaded (Pre Vene) 0.5-mm-thick specimens were sintered, veneered with feldspathic porcelain (1 mm), and glazed. The color coordinates of specimens were measured with a spectroradiometer before and after 10 000 thermocycles in coffee solution. Color differences were calculated using CIEDE2000, and relative translucency parameter (RTP) values were calculated using the RTP formula. Analysis of variance (ANOVA) was used to analyze the CIEDE2000 color differences and RTP values (α=.05).
Shading technique had a significant effect on the color difference values (P=.018). For the translucency data, the 3-way ANOVA revealed a significant interaction between the fabrication technique and shading technique (P=.002). Each pair of material subgroups within each combination of fabrication technique and shading technique was found to have a significantly different RTP, except between Ext Vene and Pre Vene (P=.115).
Externally shaded translucent zirconia had a greater color change in coffee than the preshaded translucent zirconia, either in monolithic or veneered form. Fabrication technique significantly affected the RTP, and the monolithic zirconia was more translucent than the veneered zirconia.
预着色和外部着色的整体式和贴面新型半透明氧化锆的颜色稳定性和半透明度尚不清楚。
本体外研究的目的是研究制造（贴面或整体式）和着色（预着色或外部着色）技术对咖啡热循环后半透明氧化锆的颜色和相对半透明度的影响。
从预着色和外部着色的半透明氧化锆中切出不同厚度的试件（贴面 0.5 毫米，整体式 1.5 毫米）。外部着色的标本采用浸渍技术着色。外部着色（外单）和预着色（预单）整体氧化锆标本烧结上釉。外部着色（外贴）和预着色（预贴）0.5 毫米厚的标本烧结，贴面长石瓷（1 毫米），上釉。用分光光度计测量试件在咖啡溶液中 10000 次热循环前后的颜色坐标。使用 CIEDE2000 计算色差，使用 RTP 公式计算相对半透明度参数（RTP）值。使用方差分析（ANOVA）分析 CIEDE2000 色差和 RTP 值（α=0.05）。
着色技术对色差值有显著影响（P=0.018）。对于透光率数据，3 因素方差分析显示制造技术和着色技术之间存在显著的相互作用（P=0.002）。在每个制造技术和着色技术组合内的每个材料亚组之间，发现 RTP 有显著不同，除了外贴和预贴之间（P=0.115）。
与预着色的半透明氧化锆相比，无论是整体式还是贴面式，外部着色的半透明氧化锆在咖啡中的颜色变化更大。制造技术显著影响 RTP，整体式氧化锆比贴面氧化锆更透明。
