Mechanical properties of orthodontic wires covered with a polyether ether ketone tube.

OBJECTIVES: To evaluate the esthetics and frictional force of an orthodontic wire passed through a newly designed tube made of a polyether ether ketone (PEEK) resin. MATERIALS AND METHODS: Two types of standard PEEK tubes were prepared at 0.5 × 0.6ф and 0.8 × 0.9ф, and different archwires were passed through the tubes. Color values were determined according to brightness and hues. Friction was assessed with different bracket-wire combinations, and surface roughness was determined by stereomicroscopy before and after the application of friction. RESULTS: The PEEK tube showed a color difference that was almost identical to that of coated wires conventionally used in clinical practice, indicating a sufficient esthetic property. The result of the friction test showed that the frictional force was greatly reduced by passing the archwire through the PEEK tube in almost all of the archwires tested. CONCLUSIONS: Use of the new PEEK tube demonstrated a good combination of esthetic and functional properties for use in orthodontic appliances.

Mechanical and frictional properties of aesthetic orthodontic wires obtained by hard chrome carbide plating.

BACKGROUND/PURPOSE: Although aesthetic wire coating has been increasing in demand, it has problems that changes in mechanical properties and increase in frictional force. The aim of this study was to evaluate the coating of the wire, as characterized by aesthetics, in terms of low and constant friction and mechanical properties. MATERIALS AND METHODS: Hard chrome carbide-plated (HCCP) wires (HCCP group), commercially available polymer-coated wires (P group), rhodium-coated wires (R group), and uncoated wires (control group) were used. For all wire types, a stainless steel wire of dimensions 0.017 inch × 0.025 inch was used. They were evaluated by three-point bending, friction testing, surface observation, and colorimetric testing. RESULTS: The HCCP group was not significantly different from the control group in terms of flexural strength (σ) and flexural modulus (E) (σ: p = 0.90, E: p = 0.35). However, it was significantly inferior compared to the three other groups in terms of the maximum static and kinetic frictional forces under both dry and wet conditions (p < 0.05). In the surface observation, scratches were observed on the wire after the friction test. In the colorimetric test, no significant difference was observed between the HCCP group and the R group (p > 0.05). CONCLUSION: The mechanical properties of the HCCP wire were not significantly different compared to the control group. The frictional force of the HCCP wire was significantly lower than the other group. Therefore, the HCCP wire was suggested to increase the efficiency of tooth movement in clinics.