Introduction: Coated archwires improve aesthetics during orthodontic treatment. However, little is known regarding
their clinical benefit. This randomised controlled trial (RCT) compared the tooth alignment (TA), coating loss (CL),
colour change (∆E*), and patient perception of coated archwires with their controls. Details of ∆E* and perception were reported in the second part of the articles. Methods: This RCT was done at three centres. Participants
were randomised to receive one of four treatment interventions using 0.014” superelastic coated nickel-titanium
archwires from Orthocare, RMO, G&H, and conventional uncoated 3M Unitek® archwires. These archwires were
ligated during bonding and collected after eighth week and questionnaires were distributed to participants in the
experimental groups only. After removal, TA and CL were measured using Little’s Irregularity Index and Autodesk®
AutoCAD® software, respectively. At the time of this preliminary reporting, 84 participants had completed the trial. Two archwires fractured and were excluded. Therefore, 166 archwires (n = 166) were analysed. Results: Only
non-extraction cases showed statistically significant differences in TA change between all groups (p = 0.005) and
RMO showed significantly lowest mean of TA (1.5 mm). RMO and Orthocare showed significant TA change in the
upper and lower arches (p = 0.037, 0.048). CL was found to be insignificant for both extraction and non-extraction
cases (p >0.05). Comparison between upper and lower arches revealed no significant difference in TA and CL in all
groups (p >0.05). Conclusion: From this preliminary analysis, Orthocare provides better TA in non-extraction cases
despite highest percentage of coating loss.