Determining the Corrosion Rates of Ni-Ti Instruments in Different Irrigants

The purpose of this study, was to evaluate and compare the electrochemical corrosion rate of nickel-titanium rotary files when immersed in rrigation solutions. Ni-Ti rotary files (ProTaper F 2 Rotary – Dentsply Maillefer, Ballaigues, Switzerland) were immersed in 5.25% NaOCl,17% EDTA, 10% citric acid and MTAD irrigants and the corrosion rates were determined electrochemically by the Tafel extrapolation method. Data was obtained with a potentiostat, a voltage scan generator and a recorder. The irrigants were filled into a pyrex glass cell. Cutting flutes of files were immersed in the irrigating solutions and kept for 20 min in the cell prior to each experiment, so that the rest potential of the electrode could be attained. A Saturated calomel electrode was used as a reference and platinium plate was used as a counter electrode. In the experiments, currentpotential curves were obtained and statistical analysis of the data was performed by using the Kruskal-Wallis one-way. According to the results of this study, corrosion rates of Ni-Ti rotary files immersed in irrigation solutions were found 10% citric acid 5.25%NaOCl 17% EDTA MTAD respectively.