Complete Lower Dentures on 1 or 2 Implants
A Randomized Clinical Trial Comparing Patient Satisfaction and Prosthetic Outcomes With Mandibular Implant Overdentures Retained by 1 or 2 Implants
1 other identifier
interventional
86
1 country
1
Brief Summary
This study is a randomized clinical trial to compare patient satisfaction and prosthetic outcomes with lower dentures retained by one or two implants. The investigators long-term objective is to establish evidence of the cost-effectiveness of a single implant intervention for improving tolerance to complete dentures. The investigators MAIN AIM will be to investigate patient satisfaction between and within groups with mandibular dentures retained by one or two implants over five years, and SECONDARILY to investigate the survival of implants, and the frequency of events to maintain the dentures and prosthetic attachments as clinically serviceable. Furthermore, multivariate analysis can assess the prediction of patient satisfaction with implant dentures based on various possible factors including age, health, demography and socioeconomic status, number of implants, and maintenance needs. Patient satisfaction will be measured by means of Visual Analogue Scales (VAS) including a measure of overall satisfaction and various specific aspects of satisfaction such as appearance, stability and comfort of the dentures. The CENTRAL HYPOTHESIS is that mandibular complete dentures retained by single implants are at least as satisfying to patients over a five years period as those retained by two implants for the same period. The SECONDARY HYPOTHESES are that: i) there is no difference over five years between groups in the survival of original implants, or in the number of events for maintenance of the dentures or implant attachments; and ii) using each treatment group as it's own control, there is no change in patient satisfaction with lower dentures retained by either one or two implants during the five year loading period.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for not_applicable
Started Nov 2002
Longer than P75 for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
November 1, 2002
CompletedFirst Submitted
Initial submission to the registry
April 8, 2014
CompletedFirst Posted
Study publicly available on registry
April 21, 2014
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 1, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
June 1, 2027
June 19, 2019
June 1, 2019
24.6 years
April 8, 2014
June 17, 2019
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Self-assessed VAS satisfaction with the mandibular denture
Self-assessed satisfaction is measured on a 10 cm uninterrupted visual analogue scale (VAS) representing a continuum of feelings, with "unsatisfied" at one end and "satisfied" at the other. Each participant makes a global assessment of their satisfaction by marking an X on the line at a point corresponding to their response to the question: "How would you evaluate your 'overall satisfaction' with your lower denture?". A research assistant translates the mark into a number from 0 to 100 by superimposing a template with numbered intervals from 0 to 100 mm.
Annually during 10 years after attaching the mandibular implant denture
Secondary Outcomes (7)
Change in self-assessed VAS satisfaction with the mandibular denture
From baseline (before implants) to each annual followup for 10 years after attaching the mandibular implant denture
Cumulative Implant Survival
During the 10 years after attaching the mandibular implant denture
The frequency of prosthetic maintenance events for the mandibular implant overdenture
During 10 years after attaching the mandibular implant denture
Time to provide the initial surgical and prosthetic treatment for the mandibular implant overdenture intervention
From baseline (before implants) until attachment of the mandibular implant denture, 6 weeks after implant placement
Costs to provide the initial surgical and prosthetic treatment for the mandibular implant overdenture intervention
From baseline (before implants) until attachment of the mandibular implant denture, 6 weeks after implant placement
- +2 more secondary outcomes
Study Arms (2)
1 implant
ACTIVE COMPARATORParticipants receive the following: 1 implant placed surgically in the mandibular midline; Soft reline of the existing complete lower denture; 2.25mm ball patrix placed on 1 healed implant; and Reline with 1 retentive matrix in the lower denture.
2 implants
ACTIVE COMPARATORParticipants receive the following: 2 implants placed surgically in the mandibular canine sites; Soft reline of the existing complete lower denture; 2.25mm ball patrices placed on 2 healed implants; and Reline with 2 retentive matrices in the lower denture.
Interventions
Participants receive an implant in the mandibular midline using a surgical flap procedure with local anaesthesia.
Participants receive implants bilaterally in the site of the mandibular canines using a surgical flap procedure with local anaesthesia.
Participants receive a soft reline of the existing complete lower denture approximately 10 days after placement of the implant(s).
A 2.25mm ball patrix is screwed onto the 1 implant approximately six weeks after placement of the implant.
2.25mm ball patrices are screwed onto the 2 implants approximately six weeks after placement of the implants.
Participants have their complete lower denture relined with a laboratory-processed acrylic resin to incorporate 1 retentive matrix in the denture-base to retain on the implant.
Participants have their complete lower denture relined with a laboratory-processed acrylic resin to incorporate 2 retentive matrices in the denture-base to retain on the implants
Eligibility Criteria
You may qualify if:
- functional in English or accompanied by a responsible adult who can provide translation services
- able to consent to, and participate in, the treatment provided
- available for the duration of the study
- edentulous and with at least six month's experience with conventional complete dentures
- currently wearing conventional complete dentures that are esthetically satisfactory to the patient and technically acceptable in the judgment of the study prosthodontist(s)
- medically/psychologically suitable for implant surgery in the judgment of the study dentists
You may not qualify if:
- insufficient alveolar bone height for implant(s) (\< 10 mm)
- history of head and neck radiation
- systemic or neurological disease, including: American Society of Anesthesiologists (ASA) Class 3 with recently diagnosed severe systemic disease, e.g. recent (within 6 months) myocardial infarction or stroke; risks associated with bacteraemia, e.g. immune compromise, steroids, in-dwelling catheters, stents, prosthetic heart valves, etc.; Type 1 diabetes, pituitary and adrenal insufficiency, and untreated hypothyroidism; chronic granulomatous disease, e.g. tuberculosis and sarcoidosis; bone disease, e.g. histiocytosis X, Paget's disease, fibrous dysplasia; history of congenital or acquired uncontrolled bleeding, e.g. coumadin
- previous oral implant treatment
- need for additional pre-prosthetic surgery
- need for new complete dentures
- medically/psychologically unsuitable for surgery in the opinion of the study dentists
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- University of British Columbialead
- ITI International Team for Implantology, Switzerlandcollaborator
- Canadian Institutes of Health Research (CIHR)collaborator
- Straumann Canada Ltd.collaborator
Study Sites (1)
Department of Oral Health Sciences, University of British Columbia
Vancouver, British Columbia, V6T 1Z3, Canada
Related Publications (5)
Walton JN, MacEntee MI. Choosing or refusing oral implants: a prospective study of edentulous volunteers for a clinical trial. Int J Prosthodont. 2005 Nov-Dec;18(6):483-8.
PMID: 16335167BACKGROUNDWalton JN, MacEntee MI. Screening and enrolling subjects in a randomized clinical trial involving implant dentures. Int J Prosthodont. 2008 May-Jun;21(3):210-4.
PMID: 18548957BACKGROUNDWalton JN, Glick N, Macentee MI. A randomized clinical trial comparing patient satisfaction and prosthetic outcomes with mandibular overdentures retained by one or two implants. Int J Prosthodont. 2009 Jul-Aug;22(4):331-9.
PMID: 19639067RESULTGonda T, Maeda Y, Walton JN, MacEntee MI. Fracture incidence in mandibular overdentures retained by one or two implants. J Prosthet Dent. 2010 Mar;103(3):178-81. doi: 10.1016/S0022-3913(10)60026-1.
PMID: 20188240RESULTBryant SR, Walton JN, MacEntee MI. A 5-year randomized trial to compare 1 or 2 implants for implant overdentures. J Dent Res. 2015 Jan;94(1):36-43. doi: 10.1177/0022034514554224. Epub 2014 Oct 27.
PMID: 25348544RESULT
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Stephen R. Bryant, DDS, PhD
University of British Columbia
- STUDY DIRECTOR
Michael I. MacEntee, LDS, PhD
University of British Columbia
- STUDY DIRECTOR
Joanne N. Walton, DDS
University of British Columbia
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Assistant Professor
Study Record Dates
First Submitted
April 8, 2014
First Posted
April 21, 2014
Study Start
November 1, 2002
Primary Completion (Estimated)
June 1, 2027
Study Completion (Estimated)
June 1, 2027
Last Updated
June 19, 2019
Record last verified: 2019-06