A study on cytochrome c oxidoreductase for bonding a tri-n-butylborane-initiated luting agent to dentin.

The purpose of this study was to investigate the effectiveness of cytochrome c, an oxidoreductase, in terms of initiation of polymerization in dentin bonding. The efficacy of experimental dentin primers was evaluated via the bonding of a luting agent to dentin. The eight primers evaluated were cytochrome c aqueous solutions, four with 35 wt% 2-hydroxyethyl methacrylate (HEMA) and four without. The concentrations of cytochrome c in the primers were 0, 0.01, 0.1, and 1[corrected] micromol/g. The luting agent (Super-Bond C&B) consisted of methyl methacrylate (MMA), 4-methacryloyloxyethyl trimellitate anhydride (4-META), and tri-n-butylborane (TBB) initiator. Bovine dentin surfaces were flattened, etched with an aqueous solution of 10 wt% phosphoric acid, primed, and then bonded with stainless steel rods. After 1-day immersion in water, tensile testing revealed that the bond strength was influenced by the application of cytochrome c and HEMA. The maximum bond strength of 24.6 MPa was recorded with aqueous HEMA primer containing 10 micromol/g cytochrome c. This bonding technique, combining oxidoreductase with Super-Bond C&B, may potentially be applied for seating resin-bonded restorations.