An in vitro study of a few crystal growth solutions on the bracket shear bond strength

Jeon, Yun Ok; Lee, Ki Soo

Abstract

The purpose of this study was to compare bracket shear bond strengths of th crystal growth solutions wi those of the 37% phosphoric acid etch technique. The 4 crystal growth solutions were made experimentally in th lab, that is (1)30% polyacrylic acid solution containing 0.3 M sulfuric acid (ES 1), (2)30% polyacrylic acid solution containing 0.6 M solution acid (ES 2), (3)30% polyacrylic acid solution containing 0.3 M solution acid and 0.6M lithium sulfate(ES 3), (4)30% polyacrylic acid solution containing 0.3 M solution acid and 5% phosphoric acid (ES 4). The 37% phosphoric acid solution used as a control. Bovine lower incisor tooth enamel was treated by the above solutions for 60 sec, washed out for 20 sec with slow water stream, and bonded lower anterior edgewise bracket with the light curing orthodontic composit resin adhesives. The teeth bonded brackets were stored in the distilled water at room temperature for 24h, and followed to test the bracket shear bond strength. The acid etch technique showed 177.6kg/cm(2) of mean shear bond strength which was the highest among the enamel treatment solutions. ES 1 shown 58.4 kg/cm(2) of mead shear bond strength and the of ES 4 showed 66.5 kg/cm(2). There was no significant difference between the two(p>0.05). Es 2 showed 110.6kg/cm(2) of mean shear bond strength which was 62.3% of that of acid etch technique. ES 3 showed 131.3kg/cm(2) of mead shear bond strength which was the highest among experimental crystal growth solution and which was 74% of that of acid etch technique. The shear bond strengths of the crystal growth solutions and were significantly lower that that of acid etch technique(p<0.05). The results suggest that bracket shear bond strength of 30% polyacrylic acid solution containing 0.3M sulfuric acid and 0.6M lithium sulfate were showed the highest, it is low for the clinical application of this solution.