A 5-year randomized trial to compare 1 or 2 implants for implant overdentures

Area of Science:

• Dentistry
• Prosthodontics
• Implantology

Background:

• Edentulism affects oral function and quality of life.
• Implant-retained overdentures offer improved stability and satisfaction compared to conventional dentures.
• The optimal number of implants for mandibular overdentures remains a subject of investigation.

Purpose of the Study:

• To compare patient satisfaction with mandibular complete overdentures retained by either one or two implants over a 5-year period.
• To evaluate changes in satisfaction from baseline to 5 years.
• To assess differences in implant survival and prosthodontic maintenance between the groups.

Main Methods:

• A 5-year randomized clinical trial involving 86 edentulous participants (mean age 67).
• Participants were randomized to receive a mandibular overdenture opposing a maxillary complete denture, supported by either one midline implant (group 1) or two canine implants (group 2).
• Patient satisfaction was measured using a visual analog scale at baseline and at 2 months, 1, 3, and 5 years post-implantation. Implant survival and maintenance were clinically assessed.

Main Results:

• After 5 years, patient satisfaction significantly increased from baseline in both groups (P < 0.001) with no significant difference between the one-implant and two-implant groups (P = 0.32).
• No implants failed in the single-implant group, while 5 implants failed before loading in 4 participants in the two-implant group.
• While not statistically significant, the single-implant group experienced nearly double the rate of fractured dentures compared to the two-implant group.

Conclusions:

• One or two-implant retained mandibular overdentures provide comparable patient satisfaction and implant survival after 5 years.
• Further research is needed to confirm the long-term efficacy of single-implant overdentures and their prosthetic maintenance requirements.