Heat treatment-improved bond strength of resin cement to lithium disilicate dental glass-ceramic

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Data

2016-06-01

Autores

Sundfeld, Daniel
Correr-Sobrinho, Lourenço
Pini, Núbia Inocêncya Pavesi
Costa, Ana Rosa
Sundfeld, Renato Herman [UNESP]
Pfeifer, Carmem Silvia
Martins, Luis Roberto Marcondes

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Resumo

This study investigated the influence of different hydrofluoric acid (HF) concentrations and heat treatments applied to a lithium disilicate dental glass-ceramic (EMX) on surface morphology and micro-shear bond strength (μSBS) to resin cement. Five HF concentrations (1%, 2.5%, 5%, 7.5% and 10%) and four different heat treatments applied before etching were assessed: 1. etching at room temperature with no previous heat treatment (control group); 2. HF stored at 70 °C for 1 min applied to the ceramic surface at room temperature; 3. HF at room temperature applied after a hot air stream is applied perpendicularly to the ceramic surface for 1 min; 4. The combination of previously heated HF and heated EMX surface. The etching time was fixed for 20 s for all groups. Etched EMX specimens were analyzed on field-emission scanning electron microscope (FE-SEM) and the μSBS was carried out on a universal testing machine at a crosshead speed of 1 mm/min until fracture. For the control groups, FE-SEM images showed greater glassy matrix dissolution and higher μSBS for 7.5% and 10% HF concentrations. The previous heat treatments enhanced the glassy matrix dissolution more evidently for 1%, 2.5% and 5% and yielded increased μSBS values, which were not statistically different for 7.5% and 10% HF concentrations (control group). HF concentrations and previous heat treatments did show to have an influence on the etching/bonding characteristics to lithium disilicate dental glass-ceramic.

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B. Electron microscopy, B. Surfaces, C. Strength, D. Glass ceramics, E. Biomedical applications

Como citar

Ceramics International, v. 42, n. 8, p. 10071-10078, 2016.