Esthetic nickel titanium wires– Do they deliver the same force?

To test the difference in loading and unloading forces delivered by six coated nickel-titanium wires and their non-coated equivalents. Commercially available six coated nickel-titanium wires and their non-coated equivalents of sizes 0.016-inch diameter round and 0.016 X 0.022-inch rectangular cross-section were procured. The wires were evaluated using a three-point bending test based on the method in ISO Standard 15841. No statistically significant differences in force values were found between coated and non-coated wires, listed by deflection in three-point bending, for these specific groups.Statistical analysis was done using SPSS version 11.5 (Chicago, III). Analysis of variance was performed with Sheffe post hoc for the mean comparison among the measurements of each loading and unloading deflection for coated and non-coated wires. Student’s t-tests was performed for the mean comparisons between non coated and coated groups for each deflection. There is no significant difference in load response between coated and non-coated nickel-titanium wires of the same size when subjected to the same deflection using a standard three-point bend test method.