Faculty of Dentistry, Department of Prosthodontics Istanbul Aydin University Besyol Mah. Akasya Sok., 34295, Istanbul, Turkey.
Faculty of Dentistry, Department of Prosthodontics, Okan University, Akfirat, Tuzla, 34959, Istanbul, Turkey.
J Dent. 2018 Apr;71:38-42. doi: 10.1016/j.jdent.2018.01.010. Epub 2018 Jan 31.
To compare the effect of material and thickness on the color stability and relative translucency parameters (RTP) for monolithic ceramics subjected to coffee thermocycling.
Four specimens each at thicknesses of 0.5, 0,7 and 1 mm were sectioned from monolithic ceramics [preshaded monolithic zirconia (MonZr), lithium disilicate (LDS) and zirconia reinforced lithium silicate (ZLS)]. The specimens were glazed and subjected to 5000 coffee thermocycling. The color coordinates of specimens were determined with a spectroradiometer and color differences and RTP values were calculated with CIEDE2000 color difference and TP formulas. ANOVA was used to analyze CIEDE2000 color difference and RTP values (α = .05).
For the color difference data, the 2-way ANOVA revealed a significant interaction between material and different thickness (P = .002). Except for 0.5 mm thick ZLS material, all materials in all thicknesses studied presented color changes within the clinically acceptable limits after coffee thermocycling. For the RTP data, the 3-way ANOVA revealed a highly significant interaction between material and different thicknesses (P < .001).
Material type and thickness can be expected to affect color change and relative translucency of the restorations made with preshaded MonZr, LDS and ZLS materials. Except for 0.5 mm thick ZLS material, color changes of all studied materials were within the clinically acceptable limits. Except ZLS material, color changes of other materials were not significantly affected by thickness. Staining in coffee was not found to affect translucency, and the materials' translucency parameters were ranked from high to low as LDS, ZLS and MonZr at each thickness studied.
比较材料和厚度对咖啡循环热老化后整体陶瓷颜色稳定性和相对透明度参数（RTP）的影响。
从整体陶瓷[预调色氧化锆（MonZr）、锂硅二酸盐（LDS）和氧化锆增强锂硅（ZLS）]中分别切出厚度为 0.5、0.7 和 1mm 的四个试件。对试件进行上釉处理并进行 5000 次咖啡循环热老化。使用分光辐射计测定试件的颜色坐标，并用 CIEDE2000 色差和 TP 公式计算色差和 RTP 值。采用方差分析（ANOVA）分析 CIEDE2000 色差和 RTP 值（α=0.05）。
对于色差数据，2 因素方差分析显示材料和不同厚度之间存在显著的交互作用（P=0.002）。除 0.5mm 厚的 ZLS 材料外，所有研究厚度的材料在咖啡循环热老化后均表现出临床可接受范围内的颜色变化。对于 RTP 数据，3 因素方差分析显示材料和不同厚度之间存在高度显著的交互作用（P<0.001）。
材料类型和厚度预计会影响预调色 MonZr、LDS 和 ZLS 材料制成的修复体的颜色变化和相对透明度。除 0.5mm 厚的 ZLS 材料外，所有研究材料的颜色变化均在临床可接受范围内。除 ZLS 材料外，其他材料的颜色变化不受厚度的显著影响。咖啡染色不会影响透明度，在每个研究的厚度下，材料的透明度参数从高到低依次为 LDS、ZLS 和 MonZr。
