Objectives: To compare the heat-activated nickel titanium (HANT), conventional NiTi and Copper NiTi archwires in terms of their effectiveness of aligning the teeth, possibility of inducing root resorption and pain perception Subjects and methods: Thirtyparticipants aged 15-30 years with mandibular anterior crowding of 4–6 mm, who required fixed orthodontic treatment were randomly allocated into the three archwires groups with each group having 10 patients. The archwire sequence in both groups was 0.014-inch followed by 0.016-inch. Each archwires were placed for a period of 4 weeks. The outcome measures included the amount of crowding assessed by using Little’s irregularity index (LII), apical root resorption, and pain perception by Visual Analogue Scale(VAS). The intra group comparison of alignment was done by using repeated measures of ANOVA whereas inter group comparison of alignment was done by ANOVA test, root resorption was tested by Paired t-test and Kruskal-Wallis test and pain perception were tested by Kruskal-Wallis test (P < 0.05)