Dental Press Journal of Orthodontics
On-line version ISSN 2176-9451
SCHEMANN-MIGUEL, Fabio et al. Comparative analysis of load/deflection ratios of conventional and heat-activated rectangular NiTi wires. Dental Press J. Orthod. [online]. 2012, vol.17, n.3, pp. 1-6. ISSN 2176-9451. http://dx.doi.org/10.1590/S2176-94512012000300007.
OBJECTIVE: This study compared the load-deflection ratios between 0.019 x 0.025-in rectangular orthodontic wires using 5 conventional preformed nickel-titanium (NiTi) and 5 heat-activated NiTi archwires from four different manufacturers (Abzil, Morelli, 3M Unitek and Ormco), totaling 40 archwires. The archwires were placed in typodonts without tooth # 11 and tested using a universal testing machine connected to a computer. RESULTS: The comparisons of mean load-deflection values of conventional NiTi wires revealed that the lowest mean-deflection ratio was found for 3M Unitek, followed by Ormco, Morelli and Abzil. Regarding the heat-activated wires, the lowest load-deflection ratio was found for Ormco, followed by 3M Unitek, Abzil, and Morelli. CONCLUSION: The comparison of mean load-deflection ratios revealed that the heat-activated wires had lowest mean load-deflection ratios, and this trend was seen during all the study. However, at 2-mm deflection, mean load-deflection ratios for heat-activated Morelli and conventional 3M Unitek wires were very similar, and this difference was not statistically significant.
Keywords : Orthodontics; Orthodontic wires; Qualitative analysis.