不同桩核材料对四种牙科底层瓷颜色的影响

目的 探讨3种桩核材料对4种牙科底层瓷颜色的影响,以期为修复医师正确选择适宜的修复材料提供参考.方法 制作A2色热压铸二硅酸锂玻璃陶瓷(Empress Ⅱ,A组)、Z2色瓷沉积氧化锆陶瓷(B组)、氧化锆陶瓷(Cercon base color,C组)、氧化锆陶瓷(Cereon base,D组)底层瓷试件各5个,A组试件厚度为0.80 mm,B～D组试件厚度为0.50 mm.采用色差计测量4组底层瓷试件在金铂合金、镍铬合金和复合树脂背景上的色度值,并计算每种底层瓷在不同背景间的色差值(△Eab*).结果 B、C和D组试件在不同背景间的色差均值分别为(0.14±0.08)、(0.90±0.20)和(0.99±0.09),不易为人眼所辨别(△Eab*<1.5),而A组试件在不同背景间的色差均值为(2.83±0.70),能够为人眼所辨别(△Eab*>1.5).结论 玻璃陶瓷易受背景颜色的影响,宜在与牙齿颜色相近的桩核条件下使用;氧化锆的遮色能力强,适用于基牙严重变色或染色以及各类非牙色桩核等情况.

Influence of background color on chromatic value of four all-ceramic system core materials

Objective To investigate the influence of post-core background color on chromatic value of four all-ceramic system core materials at clinically appropriate thicknesses. Methods Disc specimens of 15 mm in diameter and 0. 80 mm in thickness( Empress Ⅱ : Croup A) , and 0. 50 mm in thickness (In-Ceram Zirconia core; Group B; Cercon base color zirconia core: Group C; Cercon base zirconia core; Group D) were fabricated, five in each group. Au-Pt alloy, Ni-Cr alloy and visible light cured dental composite resin (A2 color) background were prepared. Samples were put on different background and their chromatic values were measured with colorimeter ( CIE-1976-L* a* b* ) . Color differences of each specimen on different background material were calculated.Results The color differences among specimens of Group A on different background material were more than 1. 5 (2. 83 ± 0. 70) which meant it could be noticeable to eyes. Those of zirconia were less than 1.5[Group B: (0. 14 ±0. 08); Group C: (0. 90 ±0. 20) ; Group D: (0. 99 ±0. 09) ]. Conclusions The influence of background color on Group A was noticeable to human eyes, and as a result, tooth-colored post should be used for this all-ceramic system. For the other three kinds of zirconia core material system, the color differences among specimens on different background material were unnoticeable. Therefore the three all-ceramic systems have excellent color masking ability and can be used on all color background.