Comparison of Efficiency of Bonded retainers and Vacuum formed retainers- A Randomized Clinical trial

Background: Major goal of orthodontic treatment is long term stability of the corrected teeth after orthodontic treatment. After orthodontic treatment there is always chance of relapse. To prevent relapse several appliances are available as a retention device such as bonded fixed retainers, vacuum formed retainers, removable Hawley retainer, Begg’s retainer. Now a days vacuum formed retainer has become more acceptable due to low cost, esthetic and easy fabrication. Objective: The purpose of this study was to analyze the clinical success of bonded retainers with vacuumformed retainers, as far as keeping up the consequences of orthodontic treatment in the lower arch as long as a year after debond. Methods: This was a randomized clinical trial (RCT) carried out at the department of Orthodontics, Bangabandhu Sheikh Mujib Medical University, Dhaka. In the study a total of 40 subjects who had fulfilled the selection criteria were randomly allocated to one of two groups, receiving either a vacuum-formed retainer or a bonded retainer for the mandibular arch. Qualification criteria was patients approaching debond after treatment with preadjusted edgewise fixed orthodontic appliance whose pretreatment records and study models were accessible to confirm pretreatment labial segment crowding or spacing and who had clinically acceptable alignment after treatment. The principle purpose was to research the clinical adequacy of the 2 kinds of retainers regarding changes in incisor irregularity at one year of preservation of treatment outcome. The following measurements were documented at each time point (6 and 12 months) with a digital caliper: Little’s irregularity index, intercanine width, intermolar width, arch length, extraction space opening. Result: The two groups were very much coordinated as for age, sex, clinical qualities, and treatment plans. Four patients did not attend in the follow up period and the study finished up in 36 patients. There was a statistically significant difference between the groups for changes in Little’s irregularity index and arch length. Vacuum-formed retainer group showed greater changes than the bonded retainer group (P value 0.035 and 0.022). There were also no statistically significant changes at any time for intercanine width and intermolar width. Conclusion: Some relapse is likely after fixed orthodontic treatment regardless of retainer choice, and this is negligible in many patients after debond. Bonded retainers have a superior capacity to hold the mandibular incisor arrangement after orthodontic treatment than vacuum-formed retainers. Trial registration: not done. Bangladesh Medical Res Counc Bull 2022; 48: 105-111