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

Abstract

This study investigated the effect of the bonding agent application method on the dentin bond durability of a two‐step adhesive utilizing a universal‐adhesive‐derived primer. The bonding durability of a universal adhesive was compared with those of two conventional two‐step adhesives by shear bond strength testing after thermal cycling. The primer was applied (with or without phosphoric acid pre‐etching), and the specimens were divided into three groups based on the bonding agent application method used as follows: (i) strong air‐flow application, (ii) gentle air‐flow application, and (iii) gentle air‐flow + second bonding application. The shear bond strength was determined after thermal cycling. All the factors (bonding agent application method, adhesive system, and storage condition) significantly influenced the dentin shear bond strength both with and without phosphoric acid pre‐etching. The specimens exposed to gentle air‐flow showed a higher shear bond strength than did those exposed to strong air‐flow and gentle air‐flow + second bonding. The bond durability of the tested adhesive systems was influenced by the bonding agent application method, and this trend was material dependent. The G2‐Bond Universal exhibited the same or greater dentin bond durability to the other two‐step adhesive systems.

Scanning electron microscopy observation of dentin bond interfaces in different types of resin luting cements

“…Kasahara et al demonstrated that the reaction layer was clearly observed when using universal adhesives in ER mode but was unclear underneath the hybrid layer in a threestep or a two-step ER system (Optibond FL, Scotchbond Multi-purpose Plus, and Adper Single Bond Plus) 29) . However, two-step SE adhesives in ER mode showed a clear reaction layer similar to those of universal adhesives in ER mode 30) . Hence, the reaction layer may be a Ca salt resulting from a chemical reaction between HAp in the dentin and functional monomers.…”

“…Hence, the reaction layer may be a Ca salt resulting from a chemical reaction between HAp in the dentin and functional monomers. In particular, MDP-containing adheive systems showed a clearer reaction layer than adhesive systems containing other functional monomers 15,[29][30][31] . Therefore, the strength of expression of this layer might be related to the tyeps of functional monomers employed and their ability to penetrate the hybrid layer.…”

“…On the other hand, GCA, SAL, PVT, and REC in SE mode did not show any clear resin tags, while CCP, RXU, DLA, NXO, and MLA in SE mode showed shorter and sparse resin tags. The penetration of resin monomers may be influenced by the etching mode, application time, application motion, and adhesive composition 30,32) . In particular, it is thought that active application and longer application time enhances micromechanical interactions with the underlying mineralised tissue and penetration into the tooth substrate 28,33) .…”

Universal Adhesives in Clinical Dentistry

“…7 With the intention to increase the durability by a separate hydrophobic resin application, a new twostep HEMA-free adhesive system comprising a universaladhesive-derived primer and a highly hydrophobic agent has been launched with promising in vitro results. [54][55][56] The purpose of developing two-step universal adhesives was to separate the priming and sealing steps of adhesive bonding agent to obtain a thicker adhesive-resin film thickness. 51 All the universal adhesives contain water in their composition.…”

Bond durability of a two-step adhesive with a universal-adhesive-derived primer in different etching modes under different degradation conditions

“…A new type of two-step SE adhesive system comprising a HEMA-free primer and a hydrophobic bonding agent has been developed using universal adhesive technology [24][25][26] . Unlike the traditional primer in three-or two-step adhesive systems, this new type of adhesive primer's components are similar to those of universal adhesives, containing 4-methacryloxyethyl trimellitic acid (4-MET) and 10-methacryloyloxydecyl dihydrogen phosphate (MDP) as functional monomers, in addition to a dimethacrylate monomer, filler, and photoinitiator.…”