Comparação da razão carga/deflexão entre fios ortodônticos de Ni-Ti termoativados 0,014”x0,025” e 0,016”x0,022”

The knowledge of the mechanical properties of nickel-titanium (NiTi) termoactives of the more accessible of the domestic market is still limited. Given this, the objective of this study was to evaluate and compare through deflection tests in brackets NiTi wires 03 term rectangular gauge 0.014 '' enabled x 0.025 '' and 0.016 '' x 0.022 '' of different brands (MORELLI (R), ORMCO (R) ORTHOSOURCE (R), ORTHOMETRIC (R), EURODONTO (R) and ADITEK (R)). All tests were carried out on universal testing machine EMIC DL 2000 under identical conditions and controlled at a temperature of 36 degrees C +/- 0.5 degrees C. Five measurements (N= 5) were performed for each thickness/wire tag that was deflected up to a limit of 4.0mm at a speed of 1.0mm/min. Each 0.2mm (round trip) of corresponding strength measured deflection for the construction of the graph of force x deflection at Tesc program version 3.04. Each graphic was evaluated according to the following variables: beginning of the Martensitic transformation (cN and mm), maximum strength (cN), the beginning and end of the plateau of deactivation (cN and mm) and length (mm) plateau. The average and standard deviation were calculated for all variables and statistical analysis was made by ANOVA tests 2 criteria and Turkey or Kruskal-Wallis and Dunn, a 5% level of significance. The results showed that the tests of 0.014 '' x0.025 '' ORTHOMETRIC (R) brands and ORMCO (R) showed the best results, as well as the wires of the MORELLI (R) and ORTHOSOURCE (R) to wires 0.016 '' x0.022 ''. In General, the gauge wires 0.014 '' x0.025 '' showed strength levels on the plateau of deactivation to 6 x smaller than 0.016 '' x0.022 '' caliber.