Maxillary bar overdentures on four or six posterior implants: 10‐year results from a randomized clinical trial

OBJECTIVE: To compare clinical and patient‐reported outcomes when providing maxillary overdentures on four and six splinted implants placed in the posterior region during a 10‐year follow‐up period. MATERIALS AND METHODS: Sixty‐six edentulous participants with functional maxillary denture complaints and insufficient bone volume to allow implant placement were scheduled for a bone augmentation procedure. After healing, participants were randomized to receive either four or six implants in the posterior maxilla. After 3 months of osseointegration, a bar overdenture was constructed. Implant survival, overdenture survival, clinical scores, peri‐implant bone height changes, and patient satisfaction were assessed. RESULTS: Forty‐six participants completed the 10‐year follow‐up. Implant survival was 100% in the 4‐implant group and 96.7% in the 6‐implant group. Seven new overdentures were made in the 4‐implant group and 12 new overdentures were made in the 6‐implant group due to excessive wear of the denture base and teeth. Clinical parameters did not differ significantly between groups. Mean marginal bone loss compared to baseline was 0.41 ± 0.37 mm in the 4‐implant group and 0.70 ± 1.07 mm in the 6‐implant group. Overall, patient satisfaction improved significantly, but did not differ between groups. CONCLUSION: From this 10‐year follow‐up trial, it was concluded that bar maxillary overdentures on four or six implants in the posterior region of an augmented maxilla resulted in a comparable treatment outcome with high implant survival, limited loss of peri‐implant marginal bone, and high patients' satisfaction. (Clinical trial registration number: NTR9729).