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The effect of a re-wetting agent on dentin bonding
J Perdigão1, B Van Meerbeek, M M Lopes
1Department of Operative Dentistry, School of Dentistry, University of North Carolina at Chapel Hill 27599-7450, USA. jorge_perdigao@dentistry.unc.edu
Summary
Re-wetting dried dentin with a hydroxyethyl methacrylate (HEMA) aqueous solution restores dentin bond strengths and resin infiltration. This method effectively compensates for collagen network collapse caused by drying, crucial for simplified one-bottle dental adhesives.
Area of Science:
- Dental Materials Science
- Adhesive Dentistry
- Biomaterials Engineering
Background:
- New simplified one-bottle dentin bonding systems are sensitive to substrate moisture.
- Understanding moisture effects on dentin surface is critical for optimal bonding.
Purpose of the Study:
- To compare dentin bond strengths and interfacial morphology of three one-bottle bonding systems.
- To evaluate the effect of re-wetting dried dentin with a hydroxyethyl methacrylate (HEMA) aqueous solution on bond strength and resin impregnation.
Main Methods:
- Three one-bottle dentin bonding systems were tested on three etched dentin surface conditions: moist, dried, and re-moistened with HEMA solution.
- Shear bond strengths were analyzed using ANOVA.
- Resin-dentin interfaces were examined using transmission and scanning electron microscopy.
Main Results:
- Drying dentin significantly decreased bond strengths and resulted in incomplete resin infiltration of the collagen network.
- Re-wetting dried dentin with HEMA solution restored bond strengths to levels comparable to moist dentin.
- HEMA re-wetting improved the resin impregnation of the collagen network, increasing interfibrillar space.
Conclusions:
- Aqueous HEMA solution can effectively compensate for dentin surface dryness induced by air-drying after etching.
- The water content in some current ethanol- and water-based adhesives may be insufficient to prevent collagen network collapse upon drying.
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