1 Department of orthodontics , assistant professor of faculty of dentistry ,Tabriz university of medical science

2 Department of orthodontics, post graduate student of orthodontic, faculty of dentistry, Tabriz University of medical science



Background and aim: The frequency of exposure of dental personnel to infection and of patient to cross contaminated instruments has prompted concern about adequate sterilization of dental instruments. Aim of the present study was to evaluate the changes in the frictional properties of Ni-Ti orthodontic wires after sterilization with chemical agents.
Materials and methods: In the present study the friction between Ni-Ti wires measuring 16 mm in diameter and 18-slot stainless steel brackets were measured and compared in two groups as follows: 1) without sterilization (as received); 2) after chemical sterilization. Each group consisted of 30 specimens and friction was measured in a Universal testing machine.
Results: Comparison of unsterilized samples with the group sterilized with chemical agents showed a significant difference (P=0.000) in shear stress.
Conclusion: Based on the results of the present study, this sterilization techniques result in an increase in the friction of Ni-Ti orthodontic wires.