Effect of staining and repeated firing on the surface and optical properties of lithium disilicate

Jean S Miranda; Aline S P Barcellos; Carolina M MartinelliLobo; Taciana M F Caneppele; Marina Amaral; Estevão T Kimpara

doi:10.1111/jerd.12558

Effect of staining and repeated firing on the surface and optical properties of lithium disilicate

J Esthet Restor Dent. 2020 Jan;32(1):113-118. doi: 10.1111/jerd.12558. Epub 2019 Dec 19.

Authors

Jean S Miranda¹, Aline S P Barcellos¹, Carolina M MartinelliLobo¹, Taciana M F Caneppele², Marina Amaral³, Estevão T Kimpara¹

Affiliations

¹ Department of Dental Materials and Prosthodontics, São José dos Campos Dental School, Institute of Science and Technology, UNESP-Paulista State University, São José dos Campos, Brazil.
² Department of Restorative Dentistry, São José dos Campos Dental School, Institute of Science and Technology, UNESP-Paulista State University, São José dos Campos, Brazil.
³ Department of Dentistry, University of Taubaté, Taubaté, Brazil.

PMID: 31854512
DOI: 10.1111/jerd.12558

Abstract

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 (ΔE₀₀ > 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.

Keywords: color; lithium disilicate; repeated firing; roughness; translucency.

MeSH terms

Ceramics*
Color
Computer-Aided Design
Dental Porcelain*
Materials Testing
Staining and Labeling
Surface Properties

Substances

lithia disilicate
Dental Porcelain