Influence of the preheating of bonding agents on the degree of conversion and bond durability in tridimensional dentin cavities

• Published in: Journal of adhesion science and technology Vol. 27; no. 11; pp. 1226 - 1235
• Main Authors: Borges, Boniek Castillo Dutra, Rocha Correia Vilela, Ana Raquel, Cavalcanti Silva-Junior, Antônio, Alves da Silva-Junior, Charry, Antonio Botelho, Marco, José Souza-Junior, Eduardo, Alexandre Coelho Sinhoreti, Mario, Braz, Rodivan, Antônio Japiassú Resende Montes, Marcos
• Format: Journal Article
• Language: English
• Published: Abingdon Routledge 01.06.2013; Taylor & Francis
• Subjects: Applied sciences; Biological and medical sciences; Composites; degree of conversion; Exact sciences and technology; failure analysis; Forms of application and semi-finished materials; Head and neck surgery. Maxillofacial surgery. Dental surgery. Orthodontics; in vitro; Maxillofacial surgery. Dental surgery. Orthodontics; Medical sciences; Polymer industry, paints, wood; preheating; stress; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology of polymers; Dentin; Conversion rate; Temperature effect; Silica; failure analysis; Composite material; Property formulation relationship; preheating; Crosslinked copolymer; Oxidation resistance; Optical properties; Surface properties; Biomaterial; Chemical properties; Adhesive; Photochemical copolymerization; stress; Adhesivity; Durability; Organic silane; Shrinkage; Experimental study; Dental restoration; in vitro; Commercial form; Methacrylate copolymer; degree of conversion
• ISSN: 0169-4243; 1568-5616
• DOI: 10.1080/01694243.2012.736190

Objectives: The aim of this study was to evaluate the degree of conversion (DC) of dental bonding agents at different temperatures and the bond durability of restorations bonded with preheated dental bonding agents. Materials and methods: Three multistep adhesive systems, including one 3-step etch-and-rinse (Adper Scotchbond Multipurpose Plus) and two 2-step self-etching systems (Clearfil SE Bond; Filtek Low-Shrinkage Adhesive System), were evaluated. Dental bonding agents were preheated at 25, 37, and 60 °C. Bar-shaped specimens (n = 5) were prepared for DC analysis. Fourier Transform Infrared/Attenuated Total Fluorescence spectra were obtained, and the DC was calculated by comparing the aliphatic bonds/reference peaks of nonpolymerized and polymerized materials. For bond durability analysis, tridimensional dentin cavities were prepared in 180 bovine incisors, which were then restored. Samples were stored in water for 24 h, and half of them were subjected to additional degradation with 10% NaOCl for 5 h. The push-out bond strength test was performed in a universal testing machine until failure. Failure modes were analyzed by scanning electron microscopy. Data were analyzed by analysis of variance (ANOVA) and Tukey's tests (p < 0.05). Results: Dental bonding agents preheated at 60 °C showed higher DC values than those preheated at 25 and 37 °C. The temperature of the dental bonding agent did not influence the bond durability, although fewer adhesive failures were observed in restorations bonded with dental bonding agents at 60 °C. Conclusion: Although the preheating of dental bonding agents can increase the DC, it may not improve the bond durability of dentin restorations.