In vitro shear bond strength of orthodontic bondings without liquid resin

This study aimed at evaluating the early shear bond strength of enamel-comp osite-bracket adhesion accomplished without the use of liquid resin. Orthod ontic brackets were bonded to the buccal surfaces of healthy extracted prem olars in the test group by Transbond XT (n = 8) and Phase II in = 8) compos ites but not the enclosed liquid resins in these products. Brackets bonded with the same materials (n 8 for each) along with their corresponding Liqui d resin sen ed as controls. The specimens were tested for shear bond streng th after 24-h storage in water at 37 degrees C. The fractured surfaces were graded with Adhesive Remnant Index (ARI) under a 2x-dissection microscope. Enamel of the randomly selected test and control specimens was dissolved b y 20% formic acid. Afterwards, the enamel side of the bonding materials in both groups (n = 4) was examined under the scanning electron microscope. AN OVA was used for statistical analyses. Our laboratory data suggest that the enamel adhesion produced by these two commercial materials without the use of liquid resin does not differ significantly in their early in vitro shea r bond strength.