Evaluation of the effect of different brackets and bonding agents on the shear bond strength in the laboratory environment

Orhan Çiçek, Evaluation of the Effect of Different Brackets and Bonding Agents on the Shear Bond Strength in the Laboratory Environment, University of Zonguldak Bülent Ecevit, Faculty of Dentistry, Department of Orthodontics, Specialty Thesis, Zonguldak, 2018. The aim of this study was to evaluate the effect of different types of brackets and bonding agents on the shearing strength by in vitro tests. 10 different types of brackets were divided into 2 groups by using 2 different adhesive. In Group 1, TransbondTM XT; In Group 2, TransbondTM Plus self-etching primer was used. The brackets were tested with a fatigue device which applied 10 N-force at a speed of 300 mm/min. The number of strokes of the brackets were determined and these data were examined by statistical analysis. The number of strokes of brackets showed variability depending on the differences between the type of adhesive and the type of bracket used. The majority of these differences were statistically significant (p<0.05). There was no statistically significant difference between APC Victory and Victory metal brackets. In Group 2, Equilibrium® 2 metal brackets showed a significantly higher shearing strength compared to all brackets except ceramic brackets. Clarity Advanced ceramic and Clarity SL self-ligating ceramic brackets were not found to be statistically significant when compared to their shearing strength. Gemini SL self-ligating metal brackets showed significantly higher shearing strength compared to Mini Sprint® and Mini Master metal brackets. In Clarity Advanced ceramic brackets, enamel and dentin damage were observed in 2 samples. In a great majority of Gemini Clear ceramic brackets, fractures were observed in the bracket wings. In acid etching technique, significantly higher shearing strength was observed compared to self-etching technique. Shearing strength of 3M Unitek and Dentaurum metal brackets were found significantly higher than Forestadent and American Orthodontics metal brackets. As a result of this study, it was seen that the shearing strength of the ceramic brackets was high. Bracket brands ie; designs were seen to affect the shearing strength. And last, it was seen that the bonding agent was the main determinant of the level of shearing strength. Key Words: orthodontic bracket, asit etching, self-etching, shearing strength, number of strokes, comparison