An economic evaluation of maxillary implant overdentures based on six vs. four implants.

BACKGROUND: The purpose of the present study was to assess the value for money achieved by bar-retained implant overdentures based on six implants compared with four implants as treatment alternatives for the edentulous maxilla. METHODS: A Markov decision tree model was constructed and populated with parameter estimates for implant and denture failure as well as patient-centred health outcomes as available from recent literature. The decision scenario was modelled within a ten year time horizon and relied on cost reimbursement regulations of the German health care system. The cost-effectiveness threshold was identified above which the six-implant solution is preferable over the four-implant solution. Uncertainties regarding input parameters were incorporated via one-way and probabilistic sensitivity analysis based on Monte-Carlo simulation. RESULTS: Within a base case scenario of average treatment complexity, the cost-effectiveness threshold was identified to be 17,564 € per year of denture satisfaction gained above of which the alternative with six implants is preferable over treatment including four implants. Sensitivity analysis yielded that, depending on the specification of model input parameters such as patients' denture satisfaction, the respective cost-effectiveness threshold varies substantially. CONCLUSIONS: The results of the present study suggest that bar-retained maxillary overdentures based on six implants provide better patient satisfaction than bar-retained overdentures based on four implants but are considerably more expensive. Final judgements about value for money require more comprehensive clinical evidence including patient-centred health outcomes.

An eight-year follow-up to a randomized clinical trial of aftercare and cost-analysis with three types of mandibular implant-retained overdentures.

Mandibular implant overdentures increase satisfaction and the quality of life of edentulous individuals. Long-term aftercare and costs may depend on the type of overdentures. One hundred and ten individuals received one of 3 types of implant-retained overdentures, randomly assigned, and were evaluated with respect to aftercare and costs. The follow-up time was 8 years, with only seven drop-outs. No significant differences (Kruskal-Wallis test) were observed for direct costs of aftercare (p = 0.94). The initial costs constituted 75% of the total costs and were significantly higher in the group with a bar on 4 implants, compared with the group with a bar on 2 implants and the group with ball attachments on 2 implants (p = 0.018). The last group needed a significantly higher number of prosthodontist-patient aftercare contacts, mostly for re-adjustment of the retentive system. It can be concluded that an overdenture with a bar on 2 implants might be the most efficient in the long term.

A cost minimization analysis of implant treatment in mandibular edentulous patients.

PURPOSE: This study aimed to determine if implant-supported overdentures are a long-term economically efficacious therapy for edentulous patients when compared to fixed osseointegrated prostheses. MATERIALS AND METHODS: Clinical records of 25 patients from two long-term studies (fixed and overdenture) were included in this analysis. A cost minimization analysis from the patient perspective was employed. Direct clinical and time costs incurred over the 9-year period were deflated to 1995 Canadian dollars using the Consumer Price Index. National salary rates by occupation and gender were used to value patients' time, and a sensitivity analysis was carried out to assess the robustness of the results when an equal mean salary rate across treatment groups was assumed. RESULTS: The mean total, clinical, and time costs were significantly higher (Ps .05) for the fixed restoration group (dollars CAD10,748, dollars CAD10,094, and dollars CAD654, respectively) when compared to the overdenture group (dollars CAD3,665, dollars CAD3,343, and dollars CAD322, respectively). The initial, maintenance, and clinical visit costs were also significantly higher (P < or = .05) in the fixed restoration group (dollars CAD7,567, dollars CAD2,527, dollars CAD542, respectively) than in the overdenture group (dollars CAD2,505, dollars CAD830, dollars CAD292, respectively). The sensitivity analysis demonstrated that the time cost for the fixed prosthodontic group (dollars CAD488 vs dollars CAD322) was still significantly higher (P = .002), even after an equal mean salary rate was assumed. CONCLUSION: Overdenture therapy for edentulous patients is a more cost-effective treatment compared to fixed prosthodontic treatment.