Comparison of three-implant-supported fixed dentures and two-implant-retained overdentures in the edentulous mandible: a pilot study of treatment efficacy and patient satisfaction

Int J Oral Maxillofac Implants. 2011 Mar-Apr;26(2):415-26.


Purpose: The mandibular two-implant overdenture has been shown to be a highly successful treatment. However, overdenture patients who desire a fixed prosthesis may not be satisfied with a removable overdenture. This prospective study sought to compare prosthetic outcomes, patient satisfaction, and survival rates of implants between two-implant-supported overdentures (IODs) and three-implant-supported fixed dentures (ISFDs).

Materials and methods: Twenty completely edentulous patients were randomly and equally assigned to two groups. New conventional complete dentures were made, and the mandibular denture was used as a surgical guide during implant placement. Implants were placed in one stage, followed by a mandibular denture soft reline (provisional loading). Ball attachments were inserted at 8 weeks, and ISFDs were delivered at 16 weeks. IODs were connected to the attachments at 8 weeks, using each patients's existing denture. The definitive ISFDs were fabricated using computer-aided design/computer-assisted manufacture milled titanium frameworks and acrylic resin base and teeth. Patient satisfaction and panoramic radiographs were investigated at 6 and 12 months.

Results: Both treatments had significant and positive effects on patient satisfaction and quality of life. None of the 50 implants placed had failed at 12 months of follow-up; therefore, the implant survival rate was 100%. Prosthetic complications were generally rare and easily manageable.

Conclusions: Both the treatment modalities-the ISFD supported by three implants and the IOD supported by two implants-significantly and similarly improved patient satisfaction and oral health-related quality of life, and prosthetic complications were relatively rare for both treatments. Three implants can be used to support a mandibular fixed prosthesis; however, a longer observation period is needed to validate this treatment modality.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins / chemistry
  • Aged
  • Computer-Aided Design
  • Dental Implants* / psychology
  • Dental Materials / chemistry
  • Dental Prosthesis, Implant-Supported* / psychology
  • Denture Bases
  • Denture Design
  • Denture Rebasing
  • Denture Retention* / instrumentation
  • Denture Retention* / psychology
  • Denture, Complete, Lower*
  • Denture, Overlay*
  • Female
  • Follow-Up Studies
  • Humans
  • Immediate Dental Implant Loading
  • Jaw, Edentulous / rehabilitation*
  • Jaw, Edentulous / surgery
  • Male
  • Mandible / surgery*
  • Middle Aged
  • Osseointegration / physiology
  • Patient Satisfaction*
  • Pilot Projects
  • Prospective Studies
  • Quality of Life
  • Survival Analysis
  • Titanium / chemistry
  • Treatment Outcome


  • Acrylic Resins
  • Dental Implants
  • Dental Materials
  • Titanium