title: A 5-year randomized trial to compare 1 or 2 implants for implant overdentures.
abstract: The hypothesis of this 5-y randomized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 mandibular implants. Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants (mean age, 67 y) was randomly allocated to receive either 1 implant in the midline (group 1) or 2 implants in the canine areas (group 2) attached to a mandibular overdenture opposing a maxillary complete denture. Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants, as well as at 2 mo and 1, 3, and 5 y with implant overdentures, whereas implant survival and prosthodontic maintenance were assessed by clinical examination. After 5 y, 29 participants in group 1 and 33 in group 2 were available, with most dropouts due to death. Satisfaction with the implant denture after 5 y was significantly (P < 0.001) higher than at baseline in both groups and remained with no significant difference (P = 0.32) between the groups. No implants failed in group 1 but 5 failed before loading in 4 participants in group 2. Most participants required maintenance or occasionally denture replacement, and although differences between the groups were not statistically significant, group 1 experienced almost twice as many fractured dentures usually adjacent to the implant attachment. We conclude that there were no significant differences after 5 y in satisfaction or survival of implants with mandibular overdentures retained by 1 implant or 2 implants. Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implications of prosthetic maintenance with implant overdentures (ClinicalTrials.gov: NCT02117856).
authors.affiliation: Division of Prosthodontics and Dental Geriatrics, Department of Oral Health Sciences, University of British Columbia, Canada r.bryant@ubc.ca.
authors.forename: S R
authors.initials: SR
authors.lastname: Bryant
authors.affiliation: Division of Prosthodontics and Dental Geriatrics, Department of Oral Health Sciences, University of British Columbia, Canada.
authors.forename: J N
authors.initials: JN
authors.lastname: Walton
authors.affiliation: Division of Prosthodontics and Dental Geriatrics, Department of Oral Health Sciences, University of British Columbia, Canada.
authors.forename: M I
authors.initials: MI
authors.lastname: MacEntee
mesh_terms: D000368:Aged; D003724:Dental Arch / Q000601:surgery; D015921:Dental Implants; D019250:Dental Implants, Single-Tooth; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003823:Denture Rebasing; D003780:Denture Repair; D003781:Denture Retention; D003826:Denture, Complete, Lower; D003828:Denture, Overlay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation / Q000601:surgery; D008297:Male; D008334:Mandible / Q000601:surgery; D017060:Patient Satisfaction; D012647:Self-Assessment; D016019:Survival Analysis; D016896:Treatment Outcome; D064232:Visual Analog Scale
chemical_list: D015921:Dental Implants
keywords: complete denture; dental implant; edentulous mandible; implant-supported dental prosthesis; single-implant denture; standard of care