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CompletedNCT03691285IOD1-2Updated Apr 16, 2020

Mandibular Overdenture Retained by 1 or 2 Implants: a Cost-effectiveness Analysis

An interventional study of Mandibular Overdenture in Edentulous Mouth, sponsored by Universidade Federal de Goias. Completed at 1 site in Brazil. Per ClinicalTrials.gov, last updated 2020-04-16.

Sponsored by Universidade Federal de Goias · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 1 year 5 months after the study started (first participant enrolled Apr 2017, registered Sep 2018).
Phase
Not applicable
Study type
Interventional
Enrollment
47
Allocation
Randomized
Sex
All
01

Study summary

The aim of this study is to assess the cost-effectiveness of the mandibular overdenture retained by one and two implants, based on a randomized clinical trial.

Read the detailed description

This randomized clinical trial alongside a cost-effectiveness analysis will include 48 edentulous individuals who meet eligibility criteria. New maxillary and mandibular dentures will be fabricated for all participants following a standardized protocol. Then, participants will be randomized into one of the treatment groups: mandibular overdenture retained by two implants group or single-implant mandibular overdenture group. Each participant allocated to the single-implant mandibular overdenture group will then receive a Straumann® Standard Plus SLActive® regular neck implant (Straumann 0.33.051S/052S/053S Institute Straumann AG, Basel, Switzerland) in the mandibular midline, and the mandibular overdenture retained by two implants group will receive two implants of the same specification, in the interphoramen region. A healing abutment will be connected and the implant will be allowed to heal for approximately 3 weeks. Then, a 3.4mm retentive titanium anchor abutment (Straumann 048.439, Institute Straumann AG, Basel, Switzerland) will be connected and tightened to 35 N.cm with a torque wrench. The matrix will be incorporated to the denture using self-curing acrylic resin and the patient will be instructed to keep the upper and lower dentures firmly occluded in the habitual position until the final polymerization of the resin. Outcomes (satisfaction with the dentures and oral health-related quality of life) will be measured at baseline and at the 6- and 12-month follow-up. Direct costs related to therapies in both groups will be identified, measured and valuated for one year after treatment. Incremental cost-effectiveness ratios will be estimated and graphically presented on cost-effectiveness planes. Sensitivity analysis on the most important assumptions will be performed in order to assess the robustness of the model.

02

Conditions studied

  • Edentulous Mouth

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Keywords

  • Overdenture
  • Dental implant
  • Cost analysis
03

In context

Mouth, Edentulous

244 studies on the registry are indexed under Mouth, Edentulous; 37 are open to participants now.

This study's enrollment of 47 is above the median of 30 across 187 interventional studies indexed under Mouth, Edentulous.

Browse Mouth, Edentulous studies →

Lead sponsor

Universidade Federal de Goias is the lead sponsor of 41 studies on the registry; 3 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • No contraindications for implant surgery (mainly related to uncontrolled systemic diseases)
  • Present enough bone volume in the mandibular midline area for implant placement without the need of bone augmentation procedures.
  • Be able to understand and answer the questionnaires used in the study
  • Agree to participate by providing a written informed consent.

Exclusion criteria

Exclusion Criteria:

  • Noncompliant participants
  • Individuals who do not agree to be randomly allocated to the treatment study group
  • Presence of signs of untreated temporomandibular disorders, uncontrolled systemic or oral conditions that require additional treatments
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
47 participants (actual)

Study arms

  • Experimental
    Single-implant mandibular overdenture

    Participants allocated to this group will have an implant placed in the mandibular midline and after 3 weeks (healing period - early loading) an attachment system will be tightened and a retention matrix will be incorporated to the mandibular denture.

    Procedure: Mandibular Overdenture

  • Active comparator
    Two-implant mandibular overdenture

    Participants allocated to this group will have two implants placed in the inter-foraminal region after 3 weeks (healing period - early loading) an attachment system will be tightened and a retention matrix will be incorporated to the mandibular denture.

    Procedure: Mandibular Overdenture

Interventions

  • ProcedureMandibular Overdenture

    Placement of 1 or 2 implants in the anterior region of the edentulous mandible.

06

What researchers measure

Primary outcomes

  1. Satisfaction with the dentures

    A 100 cm graduated visual analogue scale will be used in order to assess the participants' ratings of their satisfaction with the upper and lower dentures in relation to the parameters "general satisfaction", "comfort", "stability", "aesthetics", "ability to speak" and "ability to chew". Each participant will indicate their level of satisfaction with each parameter by marking a point along the scale, in which ends mean "unsatisfied" and "satisfied", as it is closer to the beginning or the end of the scale, respectively.

    Time frame: Changes from baseline to 12 months after the intervention

Secondary outcomes

  1. Masticatory efficiency

    Masticatory efficiency will be assessed as a secondary outcome using a two-colored chewing gum test and a qualitative and quantitative colourimetric method to measure the color-mixing ability. Participants will be asked to sit upright in a dental chair and to chew the gum on their preferred chewing side for 20 cycles. Visual and electronic analysis of the chewed gums samples will be done according to the classification proposed by Schimmel et al. Analysis will be made by two investigators blinded to the study groups and treatment stage. The software ViewGum (dHAL Software, Kifissia, Greece, www.dhal.com) will be used for electronic colourimetric analysis.

    Time frame: Changes from baseline to 12 months after the intervention

  2. Pain and discomfort

    A 100 cm graduated visual analog scale will be used to evaluate participants' assessments of pain and discomfort regarding the surgical process. Each participant will indicate their level of pain and discomfort with each parameter by marking a point along

    Time frame: 24 hours, 7 days and 21 days after surgery

  3. Oral health-related quality of life impacts

    The cross-culturally adapted Brazilian version of the Oral Health Impact Profile for edentulous subjects (OHIP-EDENT) will be used. It contains 19 items divided in four different subscale domains: (I) masticatory discomfort and disability (four items), (II) psychological discomfort and disability (five items), (III) social disability (five items), and (IV) oral pain and discomfort (five items). The items are answerable by a 3-point Likert scale and responses will be summed to result an overall score. Higher scores represent worse OHRQoL.

    Time frame: Changes from baseline to 12 months after the intervention

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Study locations

1 site
  • School of Dentistry, Federal University of Goias
    Goiania, Goias 74605-220, Brazil
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References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 16, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT03691285
Lead sponsor
Universidade Federal de Goias
Responsible party
Cláudio Rodrigues Leles (Associate Professor, Universidade Federal de Goias) — Principal investigator
First posted
Oct 1, 2018
Start date
Apr 9, 2017
Primary completion
Jul 30, 2019
Completion
Jul 30, 2019
Last update
Apr 16, 2020

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Apr 2020. You cannot join it, but the record below documents what was studied.

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