title: An economic evaluation of implant treatment in edentulous patients-preliminary results.
abstract: OBJECTIVE
  Edentulous patients with denture problems benefit from implant treatment with overdenture prostheses. The aim of this prospective study was to investigate a method of analyzing cost effectiveness in dentistry. As an example, overdenture treatment with two or four implants was compared to the conventional complete denture (CD).
  
  
  METHODS
  In a self-selected trial, 20 patients each were treated with implant-retained overdentures (two implants, IRET), implant-supported overdentures (four implants, ISUP), or CDs (control group) in the edentulous mandible. A cost-effectiveness analysis was performed from the patient's perspective, with a time horizon of 6 months. Direct health-care costs were calculated in Swiss Francs (in 2000), and effects were defined as improvements in perceived chewing ability compared with the baseline value before treatment (measured on a VAS). Point estimates for mean incremental cost-effectiveness ratios were complemented with cost-effectiveness acceptability curves to account for uncertainties associated with costs and effects.
  
  
  RESULTS
  Mean incremental costs were CHF 4,329 (IRET-CD), CHF 13,360 (ISUP-CD), and CHF 9,031 (ISUP-IRET); these cost differences were all statistically significant. The mean incremental effects at 6 months were 19% (IRET-CD), 23% (ISUP-CD), and 4% (ISUP-IRET). Incremental cost-effectiveness ratios were CHF 228 (IRET-CD), CHF 581 (ISUP-CD), and CHF 2,258 (IRET-ISUP) per percentage increase in chewing ability.
  
  
  CONCLUSIONS
  From an economic point of view, IRETs were more attractive than ISUPs. The latter were associated with a statistically significant improvement in perceived chewing ability compared to CDs, but at substantially higher costs.
authors.affiliation: Clinic for Reconstructive Dentistry, University of Basel, Hebelstrasse 3, Basel CH-4056, Switzerland. N.Zitzmann@unibas.ch
authors.forename: Nicola U
authors.initials: NU
authors.lastname: Zitzmann
authors.forename: Pedram
authors.initials: P
authors.lastname: Sendi
authors.forename: Carlo P
authors.initials: CP
authors.lastname: Marinello
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003362:Cost-Benefit Analysis / Q000379:methods*; D003758:Dental Implantation, Endosseous / Q000191:economics*; D015921:Dental Implants / Q000191:economics*; D019094:Dental Prosthesis, Implant-Supported / Q000191:economics*; D003826:Denture, Complete, Lower / Q000191:economics; D003828:Denture, Overlay / Q000191:economics; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008297:Male; D008409:Mastication; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011795:Surveys and Questionnaires
chemical_list: D015921:Dental Implants