The retention characteristics of Hawley and vacuum-formed retainers with different retention protocols

Background This study aimed to compare the effectiveness of two different protocols of wearing vacuum-formed retainers (VFRs) with the standard protocol of wearing Hawley retainer in maintaining the results of orthodontic treatment. Material and Methods This single-blind randomized clinical trial consisted of 90 patients who finished orthodontic treatment at the Department of Orthodontics of Mashhad Dental School, and required removable retainers. The participants were randomly divided into 3 groups and received the following treatments. Group 1: Hawley retainers (4 months full-time and then night-only); group 2: VFR_4M (4 months full-time and then night-only); group 3: VFR_1W (1 week full-…