Bonded retainers best vacuum-formed retainers to maintain incisor alignment in maxilla and mandible after 12 months of retention: Study

Bonded retainers are best vacuum-formed retainers in maintaining alignment of incisors in the maxilla and mandible after 12 months of retention suggests a study published in the Orthodontics and Craniofacial Research.

A study compared the clinical effectiveness of V-bend bonded retainers (BR) versus vacuum-formed retainers (VFR) regarding their capacity to maintain treatment stability and survival rates after 12 months. Patients finishing orthodontic treatment were randomly allocated into two groups. The Bonded retainers group received maxillary and mandibular BRs in the lingual surfaces of the anterior teeth. The VFR group received VFRs right after fixed appliance removal. The patients were evaluated at four time points: at fixed appliances removal (T0), after 3 (T1), 6 (T2) and 12 months (T3). In each time-point digital models were obtained and analysed with the OrthoAnalyzer™ software. Treatment stability based on occlusal outcomes and retainers' survival rates were evaluated. Intergroup comparisons were performed using Mann–Whitney U-tests. The Kaplan–Meier survival plot and the log-rank test assessed the retainers' survival.

Results: Both Bonded retainers and VFR groups included 25 patients. The groups were comparable regarding their baseline characteristics. Up to 6 months, both retainers were equally effective; however, after 12 months, Bonded retainers were more effective in maintaining the incisors' alignment in the maxilla and mandible than the VFRs. No differences were noticed in the intercanine and intermolar widths, overjet and overbite. There were no differences regarding the retainers' survivability in both arches. Bonded retainers were more effective in maintaining the alignment of the incisors in the maxilla and mandible compared to VFRs after 12 months. Both retainers presented the same survival rates after the same period.