Marginal Fit of Metal-Ceramic Copings: Effect of Luting Cements and Tooth Preparation Design.

Autor: de Almeida JGDSP; Health Sciences School, Universidade de Brasilia, Brasilia, Brazil., Guedes CG; Department of Dentistry, Universidade de Brasilia, Brasilia, Brazil., Abi-Rached FO; Department of Dental Materials and Prosthodontics, Universidade Estadual Paulista Julio de Mesquita Filho, Campus de Araraquara, Araraquara, Brazil., Trindade FZ; Department of Dental Materials and Prosthodontics, Universidade Estadual Paulista Julio de Mesquita Filho, Campus de Araraquara, Araraquara, Brazil., Fonseca RG; Department of Dental Materials and Prosthodontics, Universidade Estadual Paulista Julio de Mesquita Filho, Campus de Araraquara, Araraquara, Brazil.
Jazyk: angličtina
Zdroj: Journal of prosthodontics : official journal of the American College of Prosthodontists [J Prosthodont] 2019 Jan; Vol. 28 (1), pp. e265-e270. Date of Electronic Publication: 2017 Dec 22.
DOI: 10.1111/jopr.12685
Abstrakt: Purpose: To evaluate the effect of the triad finish line design, axial wall convergence angle, and luting cement on the marginal fit of metal copings used in metal-ceramic crowns.
Materials and Methods: Schematic dies and their respective copings were cast in NiCr alloy. The dies exhibited the following finish line/convergence angle combinations: sloping shoulder/6°, sloping shoulder/20°, shoulder/6°, shoulder/20°. Marginal fit was evaluated under a stereomicroscope, before and after cementation. Copings were air-abraded with 50 μm Al 2 O 3 particles and cemented with Cimento de Zinco, RelyX U100, or Panavia F cements (n = 10/group). Data were square-root transformed and analyzed by 3-way factorial random effect model and Tukey's post hoc test (α = 0.05).
Results: Statistical analysis showed significance for the interactions finish line and convergence angle (p < 0.05), convergence angle and time (p < 0.001), and luting cement and time (p < 0.001). Sloping shoulder/20° provided the highest marginal discrepancy when compared to the other finish line/convergence angle combinations, which were statistically similar among each other. For both convergence angles and for all luting cements, the marginal discrepancy was significantly higher after cementation. Before and after cementation, 6° provided better marginal fit than 20°. After cementation, Panavia F provided higher marginal discrepancy than Cimento de Zinco.
Conclusion: Lower convergence angle combined with shoulder and a low-consistency luting cement is preferable to cement metal copings.
(© 2017 by the American College of Prosthodontists.)
Databáze: MEDLINE
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