Effectiveness of immediate bonding of etch-and-rinse adhesives to simplified ethanol-saturated dentin

Leandro Afonso Guimarães,Linda Wang,Júlio César Franco Almeida,Fernanda Cristina Pimentel Garcia,Paulo Henrique Perlatti D'Alpino

doi:10.1590/s1806-83242012000200015

Abstract

This study examined the immediate bond strength of etch-and-rinse adhesives to demineralized dentin saturated with either water or absolute ethanol. The research hypothesis was that there would be no difference in bond strength to dentin between water or ethanol wet-bonding techniques. The medium dentin of 20 third molars was exposed (n = 5). The dentin surface was then acid-etched, left moist and randomly assigned to be saturated via either water wet-bonding (WBT) or absolute ethanol wet-bonding (EBT). The specimens were then treated with one of the following etch-and-rinse adhesive systems: a 3-step, water-based system (Adper Scotchbond Multipurpose, or SBMP) or a 2-step, ethanol/water-based system (Adper Single Bond 2, or SB). Resin composite build-ups were then incrementally constructed. After water storage for 24 h at 37°C, the tensile strength of the specimens was tested in a universal testing machine (0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). The failure modes were verified using a stereomicroscope (40'). For both adhesives, no significant difference in bond strength was observed between WBT and EBT (p > 0.05). The highest bond strength was observed for SB, regardless of the bonding technique (p < 0.05). No significant interaction between adhesives and bonding techniques was noticed (p = 0.597). There was a predominance of adhesive failures for all tested groups. The EBT and WBT displayed similar immediate bond strength means for both adhesives. The SB adhesive exhibited higher means for all conditions tested. Further investigations are needed to evaluate long-term bonding to dentin mediated by commercial etch-and-rinse adhesives using the EBT approach.

Highlights

The wet-bonding technique has been regarded as being the main method for bonding etch-and-rinse adhesives to dentin.[1]
The Ethanol wet-bonding technique (EBT) and wet-bonding technique (WBT) displayed similar immediate bond strength means for both adhesives
This study evaluated the influence of the simplified ethanol-wet bonding technique on the bond strength to mid-coronal dentin by using commercial ethanol and water-based etch-and-rinse adhesive systems

Summary

Introduction

The wet-bonding technique has been regarded as being the main method for bonding etch-and-rinse adhesives to dentin.[1] In this bonding approach, the organic solvents added to hydrophilic monomers, such as acetone and ethanol, displace the water molecules from the demineralized collagen matrix.[2] As a consequence, depending on the adhesive composition, the solvent evaporation will facilitate the diffusion of the monomers throughout the demineralized dentin This favors the correct adhesive polymerization to form an interfacial hybrid layer and improves the bond strength to dentin.[3] several studies have demonstrated that the monomer infiltration is considered mostly incomplete,[4] mainly due to the hydrophilicity of the adhesive monomers. Studies have shown that adding hydrophobic monomers to the adhesives allows for higher stiffness and increased stability in an aqueous environment, improving the durability of the bonded interface compared to that observed when hydrophilic-rich adhesives are applied.[7]

Methods

Results

Conclusion