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

Author(s)

Sundfeld, Daniel ^{[1, 2]} ; Correr-Sobrinho, Lourenco ^[3] ; Pavesi Pini, Nubia Inocencya ^[2] ; Costa, Ana Rosa ^[3] ; Sundfeld, Renato Herman ^[4] ; Pfeifer, Carmem Silvia ^[1] ; Marcondes Martins, Luis Roberto ^[2]

Affiliation

^[1] Oregon Hlth & Sci Univ, Div Biomat & Biomech, Dept Restorat Dent, Portland, OR 97201 - USA

^[2] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Restorat Dent, 901 Limeira Ave, BR-13414903 Sao Paulo - Brazil

^[3] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Restorat Dent, Dent Mat Div, BR-13414903 Sao Paulo - Brazil

^[4] Sao Paulo State Univ UNESP, Aracatuba Dent Sch, Dept Restorat Dent, Sao Paulo - Brazil

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 42, n. 8, p. 10071-10078, JUN 2016.
• Web of Science Citations: 4

Abstract

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 (mu SBS) to resin cement. Five HF concentrations (1%, 2.5%, 5%, 7.5% and 10%) and four different heat treatments applied before etching were assessed: I. etching at room temperature with no previous heat treatment (control group); 2. HF stored at 70 degrees 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 mu SBS 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 mu SBS 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 mu SBS 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. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved. (AU)

• FAPESP's process: 14/23320-3 - Influence of hydrofluoric acid concentration and previous thermal treatment on bond strength of lithium disilicate glass ceramic to a dual-cure resin cement modified by thio-urethane
• Grantee: Daniel Sundfeld Neto
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/26573-7 - Effects of hydrofluoric acid concentration and thermal treatment on bond strenght to dental ceramic
• Grantee: Daniel Sundfeld Neto
• Support Opportunities: Scholarships in Brazil - Doctorate