Effect of different fabrication steps on color and translucency of a CAD-CAM feldspathic ceramic.

Autor: Sampaio CS; Department of Biomaterials, Faculty of Dentistry, Universidad de los Andes, Santiago, Chile., Belfus J; Faculty of Dentistry, Universidad de los Andes, Santiago, Chile., Avila A; Faculty of Dentistry, Universidad de los Andes, Santiago, Chile., Cordero C; Faculty of Dentistry, Universidad de los Andes, Santiago, Chile., Freitte M; Faculty of Dentistry, Universidad de los Andes, Santiago, Chile., Ferrari V; Faculty of Dentistry, Universidad de los Andes, Santiago, Chile., Atria PJ; Department of Biomaterials, Faculty of Dentistry, Universidad de los Andes, Santiago, Chile.; NYU Grossman School of Medicine, New York University, New York, New York, USA., Jorquera G; Department of Oral Rehabilitation, Faculty of Dentistry, Universidad de los Andes, Santiago, Chile.
Jazyk: angličtina
Zdroj: Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.] [J Esthet Restor Dent] 2021 Oct; Vol. 33 (7), pp. 1038-1044. Date of Electronic Publication: 2021 May 31.
DOI: 10.1111/jerd.12789
Abstrakt: Objective: To evaluate color differences (ΔE) of different fabrication steps performed on a feldspathic ceramic and relative translucency parameter (RTP) after glazing; and to evaluate their effects on the color parameters: L*, a* and b*.
Material and Methods: Computer-aided design/computer-aided manufacturing (CAD-CAM) feldspathic maxillary right central incisor ceramic crowns (Cerec Blocs; 1.4 mm thickness) were fabricated through scanning a model preparation and milling. A total of 20 specimens were used and different parameters were compared with each other for color difference (ΔE): original block, milling, polishing, glazing and try-in cements; RTP was measured after glazing. Color parameters (L*, a*, and b*) were evaluated after each step with a spectrophotometer (Vita Easyshade V) and compared using the CIEDE2000 formula. Statistical analyses were done using one-way ANOVA and post-hoc tests.
Results: The highest ΔE value was observed for Original versus Milling group (4.73) and the lowest for Polishing versus Glazing (0.49). RTP after glazing presented a value of 12.01. L*, a*, and b* parameters were different among groups. Milling group was the one that presented more differences compared to the Original block regarding L*, a*, and b* parameters.
Conclusions: Different fabrication steps resulted in perceptible color differences within themselves, and L*, a*, and b* parameters changed according to each step. All milling specimens presented unacceptable color differences when compared to the other steps, and milling specimens showed all color parameters (L*, a*, and b*) statistically different compared to the Original block. A high RTP value was observed, demonstrating that, at 1.4 mm thickness, the feldspathic ceramic presented high translucency, showing that opacification of substrate might be necessary.
Clinical Significance: Different fabrication steps can greatly affect the optical properties of the feldspathic ceramic restoration studied and cause a relevant impact when compared to the ceramic block itself. Crowns evaluated right after milling presented the highest color differences. In order to obtain optical properties as close as possible to the original feldspathic ceramic block, either polishing or polishing and glazing needs to be performed.
(© 2021 Wiley Periodicals LLC.)
Databáze: MEDLINE
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