The effects of glass fiber-reinforced plastic for orthodontic wire on the malocclusion of mild anterior crowding during the initial leveling stage: A typodont experimental study.

Purpose Recently, we developed glass fiber-reinforced plastic (GFRP) orthodontic wire made from polycarbonate and E-glass fiber. The purpose of this study was to investigate the utility of GFRP wire in a clinical orthodontic treatment setting, the typodont model was simulated with a Class I malocclusion and mild crowding (arch length discrepancy: 4.5 mm). Materials and methods GFRP round wire with a diameter of 0.45 mm (0.018 in.) was prepared using 7 μm glass fibers. As control, nickeltitanium (Ni–Ti: 0.018 inch) alloy was also evaluated. For both wire groups, we examined the difference the arch widh and the arch length in the maxillary and mandibular using superimposition of 3D virtual models before and after immersion in typodont model. We also examined the strain force and permanent deformation. Results The inclination toward the labial aspect and the major axis of the upper and lower incisors increased, respectively, after the experiment. No significant differences before and after treatment were noted between the wires. On comparing the strain force of both wires after ligating the wire (4 weeks) in the strain test, the force of the GFRP wire was slightly lower than that of the Ni–Ti wires. In addition, there was more permanent deformation in the GFRP wire than in the Ni–Ti wire (P < 0.05). Conclusion GFRP wire showed equivalent efficiency to that of commercial Ni–Ti wire in improving mild anterior crowding in a typodont experiment. Therefore, GFRP wire can be used in place of Ni–Ti wire during the initial leveling stage. [ABSTRACT FROM AUTHOR]