Back to the multi-step adhesive system: A next-generation two-step system with hydrophobic bonding agent improves bonding effectiveness

Abstract

This study evaluated the bonding effectiveness of a newly developed two-step hydrophobic bonding material. Three groups using different bonding systems were compared: BZF group, using the new bonding system (BZF-29; GC, Tokyo, Japan); GPB group, using a one-step bonding system (G-Premio Bond; GC); and SE2 group, using a two-step bonding system (CLEARFIL SE Bond 2; Kuraray Noritake Dental, Tokyo, Japan). Microtensile bond strength (µTBS) was measured after storage in water for 24 h, 3 months and 6 months (n=25/group). Fracture surfaces were observed under scanning electron microscopy. The BZF group showed significantly higher µTBS than the other groups (p<0.001). Dominant failure patterns were cohesive failure for the BZF group (48-84%), mixed failure for the SE2 group (48-60%) and interface failure between adhesive and resin composite for the GPB group (48-52%). The hydrophobicity of the BZF-29 bonding system improves the long-term bonding effectiveness between adhesive and resin composite.

Effect of Adhesive Application Method on the Enamel Bond Durability of a Two-Step Adhesive System Utilizing a Universal Adhesive-Derived Primer

“…Additionally, the stress distribution might be different because of the different mechanical properties of each adhesive layer. In particular, the HEMA-, solvent-, and functional monomer-free bonding agent in GU is thought to create a hydrophobic adhesive layer, which might have higher mechanical properties than those formed in the other adhesives [15,16]. This might explain why GU was the only adhesive to show a significantly higher SBS in the ER mode than that in the SE mode at TC 10,000 in Group III.…”

“…A recently introduced two-step adhesive system comprises a 2-hydroxyethyl methacrylate (HEMA)-free universal adhesive-derived primer and a hydrophobic bonding agent without any solvents or functional monomers. This adhesive system showed superior bond durability under thermal stress and long-term water storage when compared with conventional two-step self-etch adhesives, regardless of the tooth substrate or etching mode used [15]. Moreover, Tamura et al [16] showed that the enamel and dentin bond durability achieved under fatigue stress by the new two-step adhesive system was equivalent to that attained by a gold standard two-step self-etch adhesive, Clearfil SE Bond.…”

Influence of bonding agent application method on the dentin bond durability of a two‐step adhesive utilizing a universal‐adhesive‐derived primer

“…Three different types of two-step adhesive systems were used in the present study. G2-Bond Universal is the most recent two-step adhesive system, and utilizes universal adhesive technologies for its primer along with a highly hydrophobic bonding agent [4][5][6]. Theoretically, G2-Bond Universal can be used in the etch-and-rinse and/or self-etch mode with both enamel and dentin because the primer is similar in composition to universal adhesives [15].…”

“…This might be attributed to the characteristics of the primer and the bonding agent. G2-Bond Universal is a HEMA-free adhesive system, and the bonding agent does not contain any functional monomers or solvents, unlike Clearfil SE Bond 2 and OptiBond eXTRa [4][5][6]. HEMA is thought to be susceptible to hydrolysis, and the functional monomers in the bonding agent might facilitate hydrolysis owing to the hydrophilic moieties [22,23].…”

“…A two‐step adhesive system comprising a HEMA‐free universal‐adhesive‐derived primer and a highly hydrophobic bonding agent with superior bond durability compared to the gold standard two‐step self‐etch adhesive Clearfil SE Bond in both enamel and dentin has recently been introduced [4–6]. This two‐step adhesive system is expected to offer durable clinical success due to the absence of HEMA and could be widely used in the clinical setting owing to the versatility of the universal‐adhesive‐derived primer.…”