Degree of conversion and microhardness of resin cements photoactivated through glass ceramic.

Autor:	Pereira CB; PhD, Professor, Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil., Magalhães CS; PhD, Professor, Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil., Lages FS; PhD, Professor, Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil., Ferreira RC; PhD, Professor, Department of Social and Preventive Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil., da Silva EH; PhD, Private office., da Silveira RR; PhD, Professor, Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil., Corrêa EC; PhD, Professor, Department of Metalography, Centro Federal de Educação Tecnológica de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Fantini CL; PhD, Professor, Department of Optical Physics, Instituto de Ciências Exatas, Federal University of Minas Gerais, Belo Horizonte, Brazil., Moreira AN; PhD, Professor, Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Jazyk:	angličtina
Zdroj:	Journal of clinical and experimental dentistry [J Clin Exp Dent] 2021 Nov 01; Vol. 13 (11), pp. e1068-e1075. Date of Electronic Publication: 2021 Nov 01 (Print Publication: 2021).
DOI:	10.4317/jced.58630
Abstrakt:	Background: To assess whether glass-ceramic shade, thickness and translucency affect degree of conversion (DC) and Knoop microhardness (KHN) of resin cements photoactivated using light-emitting diode (LED) or quartz-tungsten-halogen (QTH) units. Material and Methods: Glass-ceramic blocks were cut (2, 3 and 4mm) and sintered. For DC FT Raman spectroscopy (n=3), film specimens of cements (RelyX ARC, U200, Veneer, C&B) were obtained. For KHN test (n=3), cements were inserted in cylindrical matrix and covered by polyester strip. Specimens were photoactivated (30s) using LED or QTH according to each group: direct photoactivation (DP), interposing ceramic specimens or no photoactivation (NP). Data were analysed by ANOVA and Tukey's test, Kruskal-Wallis and Dunn's tests ( p <0.05). Results: Ceramic features had significant effect on DC of RelyX ARC, U200 and Veneer ( p <0.0017). Light source had no effect ( p =0.9512). C&B and Veneer had higher DC, followed by dual cements. NP dual cements showed the lowest DC. For KHN, ceramic shade ( p =0.1717) and light source ( p =0.1421) were not significant, but ceramic translucency, thickness and resin cement were significant ( p =0.0001). KHN was higher for U200 followed by ARC, and lowest for Veneer. Conclusions: DC was affected by ceramic shade, translucency and thickness. KHN was dependent on ceramic translucency and thickness. Higher DC and KHN were achieved for dual-cured cements photoactivated through 2mm-thick low translucent or 3mm-thick high translucent glass-ceramic. Key words: Cementation, composite resin cements, dental curing lights, glass ceramics. Competing Interests: Conflicts of interest The authors declare no conflict of interest. (Copyright: © 2021 Medicina Oral S.L.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu