The effect of the strength and wetting characteristics of Bis-GMA/TEGDMA-based adhesives on the bond strength to dentin

Abstract

Objectives: This study investigated the effect of the strength and wetting characteristics of adhesives on the bond strength to dentin. The experimental adhesives containing various ratios of hydrophobic, low-viscosity Bis-M-GMA, with Bis-GMA and TEGDMA, were made and evaluated on the mechanical properties and bond strength to dentin. Materials and Methods: Five experimental adhesives formulated with various Bis-GMA/Bis-M-GMA/TEGDMA ratios were evaluated on their viscosity, degree of conversion (DC), flexural strength (FS), and microtensile bond strength (MTBS). The bonded interfaces were evaluated with SEM and the solubility parameter was calculated to understand the wetting characteristics of the adhesives. Results: Although there were no significant differences in the DC between the experimental adhesives at 48 hr after curing (p > 0.05), the experimental adhesives that did not contain Bis-GMA exhibited a lower FS than did those containing Bis-GMA (p < 0.05). The experimental adhesives that had very little to no TEGDMA showed significantly lower MTBS than did those containing a higher content of TEGDMA (p < 0.05). The formers exhibited gaps at the interface between the adhesive layer and the hybrid layer. The solubility parameter of TEGDMA approximated those of the components of the primed dentin, rather than Bis-GMA and Bis-M-GMA. Conclusions: To achieve a good dentin bond, a strong base monomer, such as Bis-GMA, cannot be completely replaced by Bis-M-GMA for maintaining mechanical strength. For compatible copolymerization between the adhesive and the primed dentin as well as dense cross-linking of the adhesive layer, at least 30% fraction of TEGDMA is also needed.

Effects of washing agents on the mechanical and biocompatibility properties of water-washable 3D printing crown and bridge resin

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Shear Bond Strength of Bisphenol a-Glycidyl Methacrylate Adhesive Resin After Application of Eucalyptus Oil Before Debonding Metallic Orthodontic Bracket

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Effect of Incorporation of Hydroxyapatite Nanorods on the Rheological Properties, Micro-shear Bond Strength and Degree of Conversion of Two Dental Adhesives

“…In addition to the nature of Bis-GMA monomer which is a viscous component due to the presence of hydrogen bonding, caused by hydroxyl groups in its molecule, as well as presence of aromatic rings. 16 Tetric-N Bond contains UDMA monomer which acts as a diluent. 17 Moreover, this evidence might reflect the difference in blends of monomers between both adhesives used in this study.…”