Comparing the closure rate of premolar extraction space using nickel titanium spring and elastomeric chain: a...

The aim of this study was to compare the orthodontic space closure rate between power chains and nickel-titanium coil springs.

In this interventional, split-mouth quasi-experimental study, the participants were allocated into two groups: Space closure by nickel titanium (NiTi) spring and elastomeric chain. The canine retraction rate was measured to the nearest 0.1mm with a Boley's gauge, using the mesial wing of the premolar bracket and the distal wing of the canine bracket as reference points. Each measurement was taken three times, and the average value was used for analysis to enhance accuracy. Blinded operators conducted measurements. The paired t-test was used to test the hypothesis and evaluate the difference in canine retraction rates between NiTi and Power Chain groups. The p-value was considered to be statistically significant at less than 0.05.

This study included 60 participants (24 females and 36 males). The mean age was 16±2.97 years (12-22 years). The sample consisted of 60 upper first premolar extraction cases on both sides. The mean canine retraction rate over 3-week intervals revealed statistically significant differences between these groups (P=0.026). The rate at 84 days proved to be significantly different (P=0.0001) between the power chain and NiTi group; the rate at 147 days showed a significant difference when the NiTi group was compared with the power chain group (P<0.05).

At all the follow-ups, the canine retraction was higher using NiTi springs than elastomeric chains.