Outcomes of maxillary bar-retained overdentures on four or six implants

Researchers found that implant and overdenture survival, peri-implant soft tissue health, marginal bone-level changes and patient-reported outcomes between maxillary dentures supported by four or six implants in the anterior region after 10 years of function were favourable and similar.

Research published by Wim Slot et al. in the Journal of Clinical Periodontology Vol 50, issue 1 (January 2023)36,44 and summarised as JCP Digest 109 aimed to evaluate bar-supported maxillary implant overdenture treatment when supported by either four or six implants after 10 years.

Patients unsatisfied with a conventional maxillary full denture benefit greatly from implant support, but long-term outcomes from randomised clinical trials on bar-supported maxillary and overdenture treatment focussing on the optimal number of implants have so far not yet been reported. Furthermore, there are no guidelines for a recommended implant position in the edentulous maxilla. Implant placement in the anterior region can save extensive surgical treatments, patient morbidity, and costs.

In this study, fifty patients were randomly assigned into two groups to receive either four or six implants. If necessary, small augmentation procedures were performed. After a submerged healing period of three months, the implants were uncovered and supplied with healing abutments.

The primary outcome was the change in marginal bone levels between baseline and 10 years. Secondary outcomes were implant survival, overdenture survival, technical/mechanical complications, changes in clinical parameters, the occurrence of peri-implant mucositis and peri-implantitis, and patient-reported outcomes. All outcomes were evaluated at one-, five-, and 10-year follow-up appointments. Patients were instructed in oral-hygiene procedures associated with bar-retained overdentures and received annual supportive care.

Researchers found that implant and overdenture survival, peri-implant soft tissue health, marginal bone-level changes and patient-reported outcomes between maxillary dentures supported by four or six implants in the anterior region after 10 years of function were favourable and similar.

Investigators concluded that in patients lacking teeth, four implants to retain a bar-supported maxillary overdenture are a viable treatment option when there is ample bone volume in the anterior maxilla to facilitate implant placement.

The research was summarized for JCP Digest by postgraduate students from the University of Bern, Bern, Switzerland.

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