Forces in initial archwires during leveling and aligning: An study.

AIM

This study measured the force deflection behavior of selected initial alignment archwires by conducting three-point bending tests under controlled tests. The study tested three wire designs, namely, co-axial multistranded stainless steel wires, nickel-titanium, and copper-nickel-titanium archwires.

MATERIALS AND METHODS

The archwires were ligated to a specially designed metal jig, simulating the arch. A testing machine (Instron) recorded activation and deactivation forces of different deflections at 37°C. Forces on activation and deactivation were compared by one-way analysis of variance (ANOVA).

RESULTS

Significant differences ( < 0.05) in activation and deactivation forces were observed among the tested wires. The co-axial multistranded wire had the lowest mean activation and deactivation forces, whereas conventional nickel-titanium wires had more mean activation and deactivation forces at different deflections.

CONCLUSION

The activation and deactivation forces were higher for nickel-titanium followed by copper-nickel titanium and co-axial wires. The amount of percentage force loss was more for co-axial wire, indicating that these wires are not ideal for initial leveling and aligning.