Maxillary overdentures supported by four or six implants in the anterior region: 10-year randomized controlled trial results

Abstract

Aim: To evaluate bar-supported maxillary implant overdenture treatment when supported by either four or six implants after 10 years. Materials and Methods: Edentulous subjects with maxillary denture complaints and ample bone volume to facilitate implants in the anterior region of the maxilla were planned for implant overdenture treatment, randomized to receive either four implants (n = 25) or six implants (n = 25) and subsequently evaluated after 10 years of function. Outcome variables included peri-implant bone-level changes, implant and overdenture survival, complications, presence of plaque, calculus and bleeding, degree of peri-implant inflammation, probing depth and patient satisfaction. Differences between the groups and between evaluation periods were tested with a Student's t-test. Results: Fourteen patients with totally 72 implants were lost to follow-up. Two patients from the six-implant group experienced implant loss (four implants), resulting in 96.1% implant survival in this group versus 100% survival in the four-implant group. Clinical, radiographical and patient-reported outcome measures did not differ statistically significant between the two groups. Patients from both groups were generally quite satisfied with the result after 10 years. Conclusions: Similar and favourable outcomes are seen in bar-supported maxillary overdentures on either four or six anteriorly placed implants after a 10-year evaluation period.