Clinical trial NCT02117856: Complete Lower Dentures on 1 or 2 Implants
Official title: A Randomized Clinical Trial Comparing Patient Satisfaction and Prosthetic Outcomes With Mandibular Implant Overdentures Retained by 1 or 2 Implants
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Tooth-loss
Edentulous Mouth
Complete Denture
Complete Lower Denture
Keywords: Implant-Supported Denture
Single-Implant Denture
Patient Satisfaction
Edentulous Mandible
Dental Implants
Standard of Care
Randomized Clinical Trial
Lead sponsor: University of British Columbia
Sponsor class: OTHER
Collaborators: name: ITI International Team for Implantology, Switzerland
name: Canadian Institutes of Health Research (CIHR)
name: Straumann Canada Ltd.
First posted: 2014-04-21
Enrollment: 86
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.


Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Self-assessed VAS satisfaction with the mandibular denture
timeFrame: Annually during 10 years after attaching the mandibular implant denture
Secondary outcomes:
measure: Change in self-assessed VAS satisfaction with the mandibular denture
timeFrame: From baseline (before implants) to each annual followup for 10 years after attaching the mandibular implant denture
measure: Cumulative Implant Survival
timeFrame: During the 10 years after attaching the mandibular implant denture
measure: The frequency of prosthetic maintenance events for the mandibular implant overdenture
timeFrame: During 10 years after attaching the mandibular implant denture
measure: Time to provide the initial surgical and prosthetic treatment for the mandibular implant overdenture intervention
timeFrame: From baseline (before implants) until attachment of the mandibular implant denture, 6 weeks after implant placement
measure: Costs to provide the initial surgical and prosthetic treatment for the mandibular implant overdenture intervention
timeFrame: From baseline (before implants) until attachment of the mandibular implant denture, 6 weeks after implant placement
measure: Time to provide prosthetic maintenance treatment for the mandibular implant overdenture
timeFrame: During 1 year after attachment of the mandibular implant denture
measure: Costs to provide prosthetic maintenance treatment for the mandibular implant overdenture
timeFrame: During 1 year after attachment of the mandibular implant denture
Other outcomes:
Locations:
city: Vancouver
country: Canada
facility: Department of Oral Health Sciences, University of British Columbia
state: British Columbia
Study officials:
affiliation: University of British Columbia
name: Stephen R. Bryant, DDS, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of British Columbia
name: Michael I. MacEntee, LDS, PhD
role: STUDY_DIRECTOR
affiliation: University of British Columbia
name: Joanne N. Walton, DDS
role: STUDY_DIRECTOR
References:
citation: 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.
citation: Walton 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.
citation: Walton 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.
citation: Gonda 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.
citation: Bryant 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.