A preliminary comparison of marginal bone-level changes, survival rates, and prosthodontic maintenances between immediately and conventionally loaded twoimplant overdentures with magnetic attachments

Purpose: This study compared marginal bone-level changes, survival rates, and prosthodontic maintenance between immediately and conventionally loaded mandibular two-implant overdentures (2-IODs) retained by magnetic attachments, over a 60-month period from implant insertion. Materials and Methods: 19 mandibular edentulous participants were randomly allocated to either an immediate-loading or a conventional-loading group. Two implants were placed in each participant via flapless surgery. The implants in the immediate- loading and conventional-loading groups were loaded with magnetic attachments on the same day as implant placement and 3 months after surgery, respectively. The marginal bone-level changes were measured at 2 weeks, and at 6, 12, 24, 36, 48, and 60 months after implant placement, using standardized periapical radiographs. Results: The mean radiographic marginal bonelevel change was –1.42 mm and –1.39 mm for the immediate-loading and conventional-loading groups, respectively at 60 months, and there was no significant difference between two groups. The cumulative survival rate was 100% and 89% for immediate and conventional loading, respectively, and there was no significant difference between two groups. Conclusions: Within the limitations of this study, the immediate-loading 2-IODs tended to require frequent maintenance and both immediately and conventionally loaded 2-IODs resulted in acceptable marginal bone-level changes