In vitro evaluation of a moisture-active adhesive for indirect bonding

The aim of this in vitro investigation was to evaluate bond strength for a cyanoacrylate adhesive in combination with an indirect bonding technique. Eighty bovine permanent mandibular incisors were randomly divided into four groups of 20 teeth each. The influence of two factors on shear bond strength was investigated: (1) type of adhesive (Smartbond cyanoacrylate, Sondhi Rapid Set composite sealant) and (2) time of debonding (30 minutes and 24 hours after bonding). Stainless steel mesh-based brackets were used. Although, bond strength was not significantly different for the two debonding time periods, significantly lower bond strength measurements were found for the cyanoacrylate adhesive (P < .001). The mean bond strength for the cyanoacrylate adhesive group was 5.44 +/- 1.65 MPa for debonding 30 minutes and 6.92 +/- 1.48 MPa for debonding 24 hours after the bonding procedure vs 16.16 +/- 5.25 MPa and 14.98 +/- 2.85 MPa for the composite adhesive groups debonded at 30 minutes and 24 hours, respectively. The Weibull analysis indicated that there was an increased risk of bond failure at clinically relevant levels of stress for indirect bonding with the cyanoacrylate adhesive.