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Effect of staining and repeated firing on the surface and optical properties of lithium disilicate
Author(s) -
Miranda Jean S.,
Barcellos Aline S. P.,
MartinelliLobo Carolina M.,
Caneppele Taciana M. F.,
Amaral Marina,
Kimpara Estevão T.
Publication year - 2020
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/jerd.12558
Subject(s) - lithium disilicate , staining , materials science , surface roughness , vickers hardness test , crystallization , dental porcelain , color difference , hardness , lithium (medication) , nuclear chemistry , chemistry , composite material , medicine , microstructure , ceramic , pathology , organic chemistry , filter (signal processing) , computer science , computer vision , endocrinology
Objective Evaluate the effect of staining and repeated firings on color, translucency and surface proprieties of CAD/CAM lithium disilicate (LD). Material and Methods One hundred eighty LD discs were made (ISO 6872) and distributed in different groups (n = 20): control (CO)—no treatment; single‐step characterization (SC)—crystallization and staining fired together; and double step characterization (DC)—crystallization and then staining. The samples were submitted to two, four, or six firings, resulting in nine groups: COII, COIV, COVI, SCII, SCIV, SCVI, DCII, DCIV, and DCVI. The color and translucency were measured by a reflectance spectrophotometer. Surface roughness (Ra) and Vickers nano‐hardness were also measured. ANOVA and Tukey statistical tests were used ( α = .05). Results Only CO and DC demonstrated significant color alterations (ΔE 00 > 1.8). SC and DC did not show changes in translucency by the number of firings ( P > .05); however, for CO ( P = .02) these values increased. Nano‐hardness was similar in all groups ( P > .05). Ra values indicated differences due to the type of characterization (SC presented the highest values) and number of firings (CO and DC groups) ( P < .01). Conclusion SC promoted color, translucency, and roughness stability after repeated firings. Clinical Significance The single characterization technic in CAD/CAM lithium disilicate presents good color, translucency, and hardness stability, which promote predictable results to monolithic restoration.