Comparative evaluation of shear bond strength and debonding properties of GC Ortho Connect composite and Transbond XT composite

Abstract

Abstract Objectives The aim of this study was to evaluate the shear bond strength (SBS) and the adhesive remnant index (ARI) of “GC Ortho Connect”, a new no-primer orthodontic composite, in comparison with Transbond XT composite. Methods Sixty extracted human premolars were randomly divided into three groups (n=20). All teeth were etched with 37% phosphoric acid after which brackets were bonded using Transbond XT composite (3M Unitek, Monrovia, USA) and its primer in group I, GC Ortho Connect composite (GC Orthodontics, Tokyo, Japan) in group II, and Transbond XT composite without its primer in group III. After 24 hr of storage in distilled water at 37°C, the SBS was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. After debonding, the ARI scores were determined under a stereomicroscope at ×20 magnification. ANOVA and the Kruskal–Wallis test were applied to analyse the data at P < 0.05. Results The mean SBS value for GC Ortho Connect composite was 15.50±3.25 MPa, which was significantly higher than the value in group I (12.66±3.3 MPa) and group III (11.18±4.94 MPa). The ARI scores showed that the GC Ortho Connect composite mainly exhibited cohesive failure; whereas, most failures in the Transbond XT composite group occurred at the enamel–adhesive interface. Conclusions The performance of GC Ortho Connect composite heralds easier and more efficient bonding in orthodontics.