Resin–dentin bonds to EDTA-treated vs. acid-etched dentin using ethanol wet-bonding

Sauro, Salvatore; Toledano, Manuel; Aguilera, Fatima Sánchez; Mannocci, Francesco; Pashley, David H.; Tay, Franklin R.; Watson, Timothy F.; Osorio, Raquel

doi:10.1016/j.dental.2009.12.008

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Volume 26, Issue 4 , Pages 368-379, April 2010

Resin–dentin bonds to EDTA-treated vs. acid-etched dentin using ethanol wet-bonding

Salvatore Sauro
- Biomaterials Science, Biomimetics & Biophotonics Research Group, King's College London Dental Institute, Floor 17 Guy's Hospital, London, UK
- Corresponding author at: Biomaterials Science, Biomimetics & Biophotonics Research Group, King's College London Dental Institute, Floor 17 Guy's Hospital, London, UK. Tel.: +44 0207 188 3874; fax: +44 0207 188 1823.
Manuel Toledano
- Department of Dental Materials, School of Dentistry, University of Granada, Colegio Máximo, Campus de Cartuja, Granada, Spain
Fatima Sánchez Aguilera
- Department of Dental Materials, School of Dentistry, University of Granada, Colegio Máximo, Campus de Cartuja, Granada, Spain
Francesco Mannocci
- Biomaterials Science, Biomimetics & Biophotonics Research Group, King's College London Dental Institute, Floor 17 Guy's Hospital, London, UK
David H. Pashley
- Department of Oral Biology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
Franklin R. Tay
- Department of Endodontics, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
Timothy F. Watson
- Biomaterials Science, Biomimetics & Biophotonics Research Group, King's College London Dental Institute, Floor 17 Guy's Hospital, London, UK
Raquel Osorio
- Department of Dental Materials, School of Dentistry, University of Granada, Colegio Máximo, Campus de Cartuja, Granada, Spain

Received 28 July 2009; received in revised form 1 October 2009; accepted 9 December 2009.

Abstract

Objective

To compare resin–dentin bond strengths and the micropermeability of hydrophobic vs. hydrophilic resins bonded to acid-etched or EDTA-treated dentin, using the ethanol wet-bonding technique.

Methods

Flat dentin surfaces from extracted human third molars were conditioned before bonding with: 37% H₃PO₄ (15s) or 0.1M EDTA (60s). Five experimental resin blends of different hydrophilicities and one commercial adhesive (SBMP: Scotchbond Multi-Purpose) were applied to ethanol wet-dentin (1min) and light-cured (20s). The solvated resins were used as primers (50% ethanol/50% comonomers) and their respective neat resins were used as the adhesive. The resin-bonded teeth were stored in distilled water (24h) and sectioned in beams for microtensile bond strength testing. Modes of failure were examined by stereoscopic light microscopy and SEM. Confocal tandem scanning microscopy (TSM) interfacial characterization and micropermeability were also performed after filling the pulp chamber with 1wt% aqueous rhodamine-B.

Results

The most hydrophobic resin 1 gave the lowest bond strength values to acid-etched dentin and all beams failed prematurely when the resin was applied to EDTA-treated dentin. Resins 2 and 3 gave intermediate bond strengths to both conditioned substrates. Resin 4, an acidic hydrophilic resin, gave the highest bond strengths to both EDTA-treated and acid-etched dentin. Resin 5 was the only hydrophilic resin showing poor resin infiltration when applied on acid-etched dentin.

Significance

The ethanol wet-bonding technique may improve the infiltration of most of the adhesives used in this study into dentin, especially when applied to EDTA-treated dentin. The chemical composition of the resin blends was a determining factor influencing the ability of adhesives to bond to EDTA-treated or 37% H₃PO₄ acid-etched dentin, when using the ethanol wet-bonding technique in a clinically relevant time period.

Keywords: Microtensile bond strength, Micropermeability, Confocal microscopy, Ethanol-saturated dentin, Hydrophobic hybrid layer