Dental and Periodontal Health with Bonded or Vacuum-formed Retainers

Objectives: To assess caries experience and periodontal health associated with bonded (BR) or vacuum-formed (VFR) retainers at 12 months post-debond. Methods: Following ethical approval, 85 consecutive patients (38 males; 47 females) wearing upper and lower fixed appliances were recruited. Prior to debond, each patient was randomly assigned to receive either a lower BR (0.018in multistrand; canine to canine) or a lower VFR (Essix C®). Retainer type preference in the upper arch was at operator's discretion. Informed consent was obtained from each subject or their parent/guardian. Fitting of each retainer type followed a standardised protocol. At debond (T1) prior to retainer placement, caries, gingival bleeding and periodontal pocketing (>3mm) were recorded for the lower six anterior teeth. Patients received oral hygiene instruction with regard to each retainer when placed. Full-time wear of VFR for one year, except at mealtimes, was advised. At 12 month review (T2), caries and periodontal health were re-assessed for the lower six anterior teeth. Results: Data were available for 48 BRs and 37 VFRs at T1; 47 BRs and 37 VFRs at T2. All patients in BR or VFR groups were caries-free at T1. At T2 all with BR were caries-free; 36(97%) with VFR were caries-free (p=0.44; Fisher's Exact test). At T1, no gingival bleeding was observed in 7 patients (15%) in BR group and in 4 patients (11%) in VFR group; at T2 18(38%) with BR and 25(68%) allocated to VFR had no gingival bleeding (p=0.006;OR 3.687, 95%CI:1.452,9.359). At T1, no periodontal pocketing was recorded in 33 patients (69%) in BR group and 31(84%) in VFR group. At T2, no pocketing was recorded in 31(66%) in BR group and 33(89%) in VFR group (p=0.053,OR=3.606,95%CI:0.985,13.201). Conclusion: Caries experience and periodontal pocketing are similar with BR or VFR but BRs are associated with poorer gingival health.