Adhesive bonding to dentin with iron (II) perchlorate primers and a tri- n-butylborane-initiated luting agent

Abstract

Objectives. This study was conducted to measure the tensile bond strength of a resin to dentin when the dentin was primed with iron (II) perchlorate modified aqueous 2-hydroxyethyl methacrylate (HEMA) or an iron (II) perchlorate modified commercial self-etching primer (ED primer, Kuraray Co.). Methods. Bovine dentin surfaces were ground flat and each specimen underwent one of the following two treatments: (1) priming with 2.0×10 −6 to 5.0×10 −4 mol/g iron (II) perchlorate in aqueous HEMA solutions after etching with 10wt% phosphoric acid; (2) priming with self-etching primers containing 4.0×10 −7 to 2.0×10 −4 mol/g iron (II) perchlorate. Each specimen was then bonded to a stainless-steel rod with a luting agent (MMA–TBB resin) consisting of methyl methacrylate (MMA), poly(methyl methacrylate) (PMMA), and tri- n-butylborane (TBB) initiator. Tensile strengths of the bonded tooth specimens were then determined after 1 day immersion in water. Results were analyzed using ANOVA and Duncan's new multiple range test ( p<0.05). Results. Tensile testing revealed the maximum mean bond strengths (22.5 MPa) when the dentin was primed with 2.0×10 −4 mol/g iron (II) perchlorate after etching with 10wt% phosphoric acid aqueous solution. The highest level of bond strength with self-etching primer (19.6 MPa) was achieved using 1.0×10 −4 mol/g iron (II) perchlorate. Significance. These bonding techniques, combining the use of iron (II) perchlorate modified HEMA primers with MMA–TBB resin, are potentially applicable for seating resin-bonded restorations.