Campanelli de Morais Dayana, de Oliveira Abu-Izze Fernanda, Rivoli Rossi Natália, Gallo Oliani Marcelo, de Assunção E Souza Rodrigo Othávio, de Siqueira Anzolini Saavedra Guilherme, Bottino Marco Antonio, Marques de Melo Marinho Renata
Department of Oral Health Sciences, The University of British Columbia, Vancouver, British Columbia, Canada.
Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, Brazil.
J Prosthodont. 2021 Dec;30(9):776-782. doi: 10.1111/jopr.13306. Epub 2021 Jan 6.
To evaluate the effect of multiple firings on the optical and mechanical properties of two dental CAD/CAM glass-ceramics.
A total of 45 specimens of each lithium disilicate-LD (IPS E.max CAD, Ivoclar Vivadent) and zirconia lithium silicate-ZLS (Vita Suprinity, Vita Zahnfabrik) material were prepared in a disk shape. These specimens were divided into three groups according to two factors: "type of ceramic" (LD and ZLS) and "numbers of firings" (Control 2F-two firings, 5F-five firings and 7F-seven firings). The firing cycles were performed according to the manufacturer's recommendations. X-ray diffraction was additionally performed to determine crystalline phases in each group, spectrophotometry was used to determine color and translucency variation, and biaxial flexural strength (BFS) evaluated the mechanical behavior. The data were analyzed individually using two-way ANOVA tests and Tukey's test at α = 0.05.
The crystalline phases did not present any change after multiple firings for either of the analyzed materials. Both commercial materials showed a significant difference regarding translucency at 7F (p = <0.01), and ZLS presented a difference in color higher than one (ΔE > 1) at 5F and 7F. Regardless of the number of firings, LD presented a higher BFS compared to ZLS (p = <0.001), and a significant increase in BFS comparing 2F and 7F (p = <0.024).
The use of multiple firings can significantly alter the color, translucency, and mechanical strength of CAD/CAM ceramics.
评估多次烧制对两种牙科CAD/CAM玻璃陶瓷光学和机械性能的影响。
分别制备45个二硅酸锂（LD，IPS E.max CAD，义获嘉伟瓦登特公司）和硅酸锂锆（ZLS，Vita Suprinity，维他齿科集团）材料的圆盘形试件。根据“陶瓷类型”（LD和ZLS）和“烧制次数”（对照组2次烧制、5次烧制和7次烧制）这两个因素将这些试件分为三组。烧制循环按照制造商的建议进行。另外进行X射线衍射以确定每组中的晶相，使用分光光度法测定颜色和透明度变化，通过双轴弯曲强度（BFS）评估机械性能。使用双向方差分析测试和Tukey检验对数据进行单独分析，α = 0.05。
对于两种分析材料，多次烧制后晶相均未出现任何变化。两种商用材料在7次烧制时的透明度均显示出显著差异（p = <0.01），ZLS在5次和7次烧制时颜色差异高于1（ΔE > 1）。无论烧制次数如何，LD的BFS均高于ZLS（p = <0.001），并且比较2次烧制和7次烧制时BFS有显著增加（p = <0.024）。
多次烧制会显著改变CAD/CAM陶瓷的颜色、透明度和机械强度。
