Effects of surface treatments, thermocycling, and cyclic loading on the bond strength of a resin cement bonded to a lithium disilicate glass ceramic.

Abstract

SUMMARY Objectives : The aim of this present study was to investigate the effect of two surface treatments, fatigue and thermocycling, on the microtensile bond strength of a newly introduced lithium disilicate glass ceramic (IPS e.max Press, Ivoclar Vivadent) and a dual-cured resin cement. Methods : A total of 18 ceramic blocks (10 mm long × 7 mm wide × 3.0 mm thick) were fabricated and divided into six groups (n=3): groups 1, 2, and 3-air particle abraded for five seconds with 50-μm aluminum oxide particles; groups 4, 5, and 6-acid etched with 10% hydrofluoric acid for 20 seconds. A silane coupling agent was applied onto all specimens and allowed to dry for five seconds, and the ceramic blocks were bonded to a block of composite Tetric N-Ceram (Ivoclar Vivadent) with RelyX ARC (3M ESPE) resin cement and placed under a 500-g static load for two minutes. The cement excess was removed with a disposable microbrush, and four periods of light activation for 40 seconds each were performed at right angles using an LED curing unit (UltraLume LED 5, Ultradent) with a final 40 second light exposure from the top surface. All of the specimens were stored in distilled water at 37°C for 24 hours. Groups 2 and 5 were submitted to 3,000 thermal cycles between 5°C and 55°C, and groups 3 and 6 were submitted to a fatigue test of 100,000 cycles at 2 Hz. Specimens were sectioned perpendicular to the bonding area to obtain beams with a cross-sectional area of 1 mm(2) (30 beams per group) and submitted to a microtensile bond strength test in a testing machine (EZ Test) at a crosshead speed of 0.5 mm/min. Data were submitted to analysis of variance and Tukey post hoc test (p≤0.05). Results : The microtensile bond strength values (MPa) were 26.9 ± 6.9, 22.2 ± 7.8, and 21.2 ± 9.1 for groups 1-3 and 35.0 ± 9.6, 24.3 ± 8.9, and 23.9 ± 6.3 for groups 4-6. For the control group, fatigue testing and thermocycling produced a predominance of adhesive failures. Fatigue and thermocycling significantly decreased the microtensile bond strength for both ceramic surface treatments when compared with the control groups. Etching with 10% hydrofluoric acid significantly increased the microtensile bond strength for the control group.

• Authors: G B Guarda, A B Correr, L S Gonçalves, A R Costa, G A Borges, M A C Sinhoreti, L Correr-Sobrinho
• Journal: Operative dentistry (Oper Dent) 2013 Mar-Apr Vol. 38 Issue 2 Pg. 208-17 ISSN: 0361-7734 [Print] United States
• PMID: 22856682 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Composite Resins
• IPS e.max Press
• Polymethacrylic Acids
• RelyX ARC
• Resin Cements
• Silanes
• Tetric ceram
• lithia disilicate
• single bond
• Water
• Dental Porcelain
• Polyethylene Glycols
• Bisphenol A-Glycidyl Methacrylate
• Glass ceramics
• Aluminum Oxide
• Hydrofluoric Acid

Topics

• Acid Etching, Dental (methods)
• Adhesiveness
• Aluminum Oxide (chemistry)
• Bisphenol A-Glycidyl Methacrylate (chemistry)
• Ceramics (chemistry)
• Composite Resins (chemistry)
• Curing Lights, Dental
• Dental Bonding
• Dental Etching (methods)
• Dental Porcelain (chemistry)
• Dental Stress Analysis (instrumentation)
• Humans
• Hydrofluoric Acid (chemistry)
• Materials Testing
• Microscopy, Electron, Scanning
• Polyethylene Glycols (chemistry)
• Polymethacrylic Acids (chemistry)
• Radiation Dosage
• Resin Cements (chemistry)
• Self-Curing of Dental Resins
• Silanes (chemistry)
• Stress, Mechanical
• Surface Properties
• Temperature
• Tensile Strength
• Time Factors
• Water (chemistry)