Simulated canine retraction with different sizes of stainless steel archwires : an in-vitro study

Abstract EN

Background : This study aimed to assess five different sizes of archwires regarding canine retraction and distopalatal rotation in an invitro model. Materials and method : A total of 50 acrylic canine teeth were fabricated as a replica to a natural tooth, to which 0.022 × 0.030 inch slot standard edgewise brackets were bonded.

They were ligated to straight.

018 inch, 0.016 × 0.022 inch, 0.017 × 0.022 inch, 0.018 × 0.022 inch, and 0.019 × 0.025 inch stainless steel archwires using loose steel ligature wire. The teeth were moved through softened wax (at 50°C) along the archwires using NiTi closed coil springs then the amount of tooth movement, and the degree of rotation were measured. Results : The descriptive statistics showed that the maximum distance of canine retraction and rotation was with 0.018 inch wire, while the minimum was with 0.019 × 0.025 archwire.

For canine retraction only a non-significant differences between 0.016 × 0.022 and 0.017 × 0.022 archwires and between 0.018 × 0.022 and 0.019 × 0.025 archwires were found, while for canine rotation the non-significant differences were between 0.017 × 0.022 and 0.018 × 0.022 archwires and between 0.018 × 0.022 and 0.019 × 0.025 archwires as detected by ANOVA test and post hoc Scheffe test.

Pearson correlation coefficient test revealed non-significant correlation between the distance moved by the canine and its degree of rotation. Conclusion : The greatest amount of canine retraction and rotation achieved with 0.018 inch stainless steel archwire, while the opposite occurred with 0.019 × 0.025 inch wire.

0.017 × 0.022 inch archwire combined properties acceptable both regarding canine retraction and rotation.