Andrade Everton Cocati, da Silva Sarah Emille Gomes, Caneppele Taciana Marco Ferraz, Machado João Paulo Barros, Leite Fabíola Pessoa Pereira, Miranda Jean Soares, Zhang Yu, E Souza Rodrigo Othávio de Assunção
Department of Dentistry, Centro Universitário Governador Ozanam Coelho (UNIFAGOC), Doutor Adjalme da Silva Botelho, Ubá, Brazil.
Department of Dentistry, Federal University of Rio Grande do Norte (UFRN), Lagoa Nova, Natal, Brazil.
J Prosthodont. 2025 Jan 7. doi: 10.1111/jopr.14007.
To assess the impact of staining and multiple firings on the mechanical, optical, and surface characteristics of zirconia-containing lithium silicate ceramics (ZLS).
Ninety ZLS discs (Suprinity, VITA Zahnfabrick) were divided according to the "Number of firings" protocol: Ctr-control, no characterization; SC-single firing cycle (for characterization, crystallization and staining simultaneously); and DC-double firing cycle (crystallization firing cycle was performed separately from the staining firing). Extrinsic pigmentation was performed to replicate the characterization of a monolithic restoration. A layer of stain and glaze was applied with a fine brush to the ceramic surface. Specimens were fired two or four cycles, designed to simulate additional staining firings for potential characterization adjustments, but without applying new stain, resulting in six groups (n = 15): Ctr, Ctr, SC, SC, DC, and DC. X-ray diffraction, color, translucency, and surface roughness analysis were also performed, and the samples were subjected to the biaxial flexural strength test. Data were subjected to one-way ANOVA, Tukey's test (α = 0.05), and Weibull analysis.
No changes in the diffractogram pattern were found, irrespective of the number of firings. The translucency (p = 0.02) and roughness (p < 0.01) of DC were significantly reduced compared to DC. DC also showed the highest flexural strength (325.52MPa), followed by SCII (271.64MPa).
Repeated firings increased the flexural strength of ZLS, where the double-step characterization technique demonstrated better statistical results than the other groups. Moreover, despite the ceramic showing good color stability, repeated firings significantly compromised its translucency.
评估染色和多次烧制对含氧化锆的硅酸锂陶瓷（ZLS）的机械、光学和表面特性的影响。
根据“烧制次数”方案将90个ZLS圆盘（Suprinity，维他齿科）分组：Ctr-对照组，无表征；SC-单次烧制循环（用于同时进行表征、结晶和染色）；DC-双次烧制循环（结晶烧制循环与染色烧制分开进行）。进行外部色素沉着以模拟整体修复体的表征。用细刷在陶瓷表面施加一层污渍和釉料。样品进行两次或四次烧制循环，旨在模拟为潜在的表征调整进行的额外染色烧制，但不施加新的污渍，从而得到六组（n = 15）：Ctr、Ctr、SC、SC、DC和DC。还进行了X射线衍射、颜色、半透明度和表面粗糙度分析，并对样品进行双轴弯曲强度测试。数据进行单因素方差分析、Tukey检验（α = 0.05）和威布尔分析。
无论烧制次数如何，衍射图谱均未发现变化。与SC相比，DC的半透明度（p = 0.02）和粗糙度（p < 0.01）显著降低。DC还显示出最高的弯曲强度（325.52MPa），其次是SCII（271.64MPa）。
重复烧制提高了ZLS的弯曲强度，其中双步表征技术显示出比其他组更好的统计结果。此外，尽管陶瓷表现出良好的颜色稳定性，但重复烧制显著损害了其半透明度。
