Resin-dentin bonds to EDTA-treated vs. acid-etched dentin using ethanol wet-bonding.
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% H(3)PO(4) (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 (1 min) 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 1 wt% 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.


CONCLUSIONS
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% H(3)PO(4) acid-etched dentin, when using the ethanol wet-bonding technique in a clinically relevant time period.
Sauro
Salvatore
S
Biomaterials Science, Biomimetics & Biophotonics Research Group, King's College London Dental Institute, Guy's Hospital, London, UK. salvatore.sauro@kcl.ac.uk
Toledano
Manuel
M
Aguilera
Fatima Sánchez
FS
Mannocci
Francesco
F
Pashley
David H
DH
Tay
Franklin R
FR
Watson
Timothy F
TF
Osorio
Raquel
R
D000134:Acid Etching, Dental / Q000379:methods*; D002614:Chelating Agents / Q000494:pharmacology*; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects*; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004492:Edetic Acid / Q000494:pharmacology*; D000431:Ethanol; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000494:pharmacology; D019279:Resin Cements / Q000737:chemistry*; D012995:Solubility; D013718:Tensile Strength; D014867:Water; D017155:Wettability
D002614:Chelating Agents; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D019279:Resin Cements; D014867:Water; D000431:Ethanol; D004492:Edetic Acid