Treatment of edentulous mandible with metal-resin fixed complete dentures: A 15- to 20-year retrospective study

The purpose of this retrospective study was to report the implant and prosthetic complications of mandibular metal-resin fixed complete dentures (MRFCDs) opposing a maxillary complete removable dental prosthesis (CRDP) in a 15- to 20-year post-placement follow-up period.

Dental records of 24 edentulous patients treated by a mandibular MRFCD and a maxillary CRDP were reviewed. Complications for the implants, MRFCDs, and CRDPs were recorded in four different recall periods: 0-5 years, 5-10 years, 10-15 years, and more than 15 years. The survival and failure times based on Kaplan-Meier statistics were analyzed using Lifetest procedures. Product-limit survival estimates were used for cumulative survival rates (CSRs).

The mean service time was 18.5 years. The CSR for the implants and MRFCDs was 91.8% at 16.9 years (confidence intervals: 85.2% and 95.5%) and 80% at 19.6 years (confidence intervals: 44.1% and 94.1%), respectively. The implant failures after 15 years occurred because of a tumor resection. Acrylic resin tooth fracture (45.8% of patients) and wear (75% of patients) were the most common complications with the MRFCD. Retaining screw complications [loosening (8.1% of retaining screws) and fracture (11.3% of retaining screws)] were also common.

The outcomes seen with MRFCD over the long term were favorable. After placement of prostheses, 1 implant loss was observed potentially due to prosthetic/hygiene/periodontal factors. However, potential maintenance complications such as acrylic resin tooth fracture and/or wear and retaining screw loosening and fracture may occur in the long term when a similar design is used for the mandible.