Single-implant Versus Two-implant Mandibular Overdentures

NCT07408778 | Recruiting

• 1 other identifier: AAUP IRB Ref: J-2025A/46/N.
• Study Type: interventional
• Target: 32
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled trial compares a mandibular overdenture retained by one implant placed in the parasymphyseal or canine region with a mandibular overdenture retained by two implants placed in the interforaminal region in completely edentulous adults. Primary outcomes are oral health-related quality of life, patient satisfaction, and masticatory performance measured by a two-color chewing gum mixing test, assessed at baseline before implant surgery and at 3, 6, and 12 months after overdenture insertion.

Conditions

Edentulism

Keywords

mandibular denture instability; poor denture retention; implant-retained overdenture

Outcome Measures

Primary Outcomes (3)

• Change from baseline in Oral Health Impact Profile for Edentulous Adults (OHIP-EDENT) total score

  Oral health-related quality of life (OHRQoL) will be assessed using the Oral Health Impact Profile for edentulous adults (OHIP-EDENT). OHIP-EDENT includes 19 items across 7 domains: functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap. Each item is rated on a 5-point Likert scale from 0 ("never") to 4 ("very often"). Total score range is 0-76; lower scores indicate better oral health-related quality of life (OHRQoL).

  Baseline (pre-surgery), 3 months after overdenture insertion, 6 months after overdenture insertion, and 12 months after overdenture insertion

• Change from baseline in McGill Denture Satisfaction Questionnaire (MDSQ) total score

  McGill Denture Satisfaction Questionnaire (MDSQ) includes 8 core questions. Each item is scored on a 100-mm VAS (0 = "no satisfaction at all"; 100 = "complete satisfaction"). Total score = sum of 8 items (range 0-800); higher scores indicate greater satisfaction.

  Baseline (pre-surgery), 3 months after overdenture insertion, 6 months after overdenture insertion, and 12 months after overdenture insertion.

• Change from baseline in masticatory performance measured by two-color chewing gum mixing test (Variance of Hue [VoH])

  Masticatory performance will be assessed using the two-color chewing gum mixing test. Chewed specimens are imaged and analyzed using ViewGum® software to calculate the Variance of Hue (VoH; range 0-1). Lower VoH indicates better color mixing (better masticatory performance).

  Baseline (pre-surgery), 3 months after overdenture insertion, 6 months after overdenture insertion, and 12 months after overdenture insertion.

Secondary Outcomes (9)

• Visual Analog Scale (VAS) for postoperative pain

  24 hours after implant surgery, 7 days after implant surgery, and 21 days after implant surgery.

• Expected and Perceived Treatment Burden Questionnaire Score (overall and stage-specific)

  Baseline (pre-surgery, expected burden); within 7 days after implant surgery (experienced surgical-stage burden); at overdenture insertion (experienced prosthodontic-stage burden).

• Marginal bone level (MBL) change around implants (mm)

  Overdenture insertion (baseline), 3 months after overdenture insertion, and 12 months after overdenture insertion

• Implant survival

  Up to 12 months after overdenture insertion.

• Peri-implant probing depth (PPD), mean per implant (mm)

  Baseline (at overdenture insertion), 3 months after overdenture insertion, 12 months after overdenture insertion.

Study Arms (2)

Single-implant mandibular overdenture (parasymphyseal/canine, preferred chewing side)

EXPERIMENTAL

One bone-level implant will be placed in the mandibular parasymphyseal/canine region on the preferred chewing side using a single-stage approach. A locator-type attachment (Sonator S) will be connected according to the manufacturer's instructions, and intraoral pick-up will be performed with cold-curing resin.

Procedure: Single-implant mandibular overdenture (parasymphyseal/canine region)

Two-implant mandibular overdenture (interforaminal)

ACTIVE COMPARATOR

Two bone-level implants will be placed bilaterally in the mandibular interforaminal region (bilateral lateral incisor-canine area) using a single-stage approach. Locator-type attachments (Sonator S) will be connected according to the manufacturer's instructions, and intraoral pick-up will be performed with cold-curing resin.

Procedure: Two-implant mandibular overdenture (interforaminal)

Interventions

Single-implant mandibular overdenture (parasymphyseal/canine region) PROCEDURE

Placement of one endosseous implant in the mandibular parasymphyseal/canine region on the participant's preferred chewing side, followed by delivery of a mandibular overdenture retained with a standardized attachment protocol and follow-up schedule.

Single-implant mandibular overdenture (parasymphyseal/canine, preferred chewing side)

Two-implant mandibular overdenture (interforaminal) PROCEDURE

Placement of two endosseous implants in the mandibular interforaminal region (bilateral lateral incisor-canine area), followed by delivery of a mandibular overdenture retained with the same standardized attachment protocol and follow-up schedule.

Two-implant mandibular overdenture (interforaminal)

Eligibility Criteria

• Age: 40 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Men and women ≥40 years.
• ASA I-II; favorable general health or adequately controlled systemic disease (e.g., hypertension, diabetes).
• Skeletal Class I relationship.
• Completely edentulous mandible and maxilla.
• Technically acceptable complete dentures in both jaws for ≥3 and ≤24 months; dissatisfaction limited to mandibular retention/stability.
• Adequate anterior mandibular bone for implant ≥3.5×10 mm confirmed on CBCT; no bone augmentation needed.
• Normal mucosal resilience (\~2 mm displacement).
• Implant sites healed ≥4 months since extraction.
• Willingness to be randomized and attend follow-ups; written informed consent.
• Primary stability target ≥25 N-cm.

You may not qualify if:

• Uncontrolled systemic disease; neurodegenerative disease; osteoporosis requiring antiresorptives.
• Chronic systemic antibiotics/steroids; bleeding disorders; active cancer therapy; metabolic bone disease; HIV.
• Investigational drug use within 30 days.
• Alcohol dependence/illicit drug use; xerostomia (stimulated flow \<0.7 mL/min).
• Heavy smoking \>20 cigarettes/day.
• TMD/orofacial pain; severe bruxism; moderate/severe cognitive impairment.
• Prior implant therapy.
• Non-adherence risk or inability to attend longitudinal visits.
• Insufficient prosthetic space for attachment housing: inter-arch vertical distance \<8.5 mm at parasymphyseal/canine region.
• Concurrent participation in another interventional study.
• Erosive lichen planus or other significant oral mucosal disease; head-and-neck irradiation history.
• Mandibular pathology on CBCT (e.g., cyst, tumor).
• Ridge dimensions \<6 mm width or \<10 mm height at planned sites.
• Active intraoral infection.

Sponsors & Collaborators

• Rola Shadid: lead

Study Sites (1)

Faculty of Dentistry/ Arab American University

Jenin, Palestine, 240 jenin, Palestinian Territories

RECRUITING

Study Officials

• Rola M Shadid, BDS, MSc

  Arab American University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Rola M Shadid, BDS, MSc

CONTACT

+970594494066; rola.shadid@aaup.edu

Jafar AbuAssba, BDS, MSc

CONTACT

00970598595800; jafar.abuassba@aaup.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Outcome assessments (questionnaires and chewing gum mixing test) are performed by a blinded assessor; participants and treating clinicians are not blinded due to the nature of the interventions.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Associate Professor, Department of Prosthodontics, Arab American University (Palestine)

Study Record Dates

• First Submitted: January 26, 2026
• First Posted: February 13, 2026
• Study Start: February 16, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2027
• Last Updated: February 17, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: Available beginning after publication of the primary 12-month results, for 3 years.
• Access Criteria: Available to qualified researchers upon reasonable request, submission of a methodologically sound proposal, and execution of a data-use agreement; data will be shared via secure file transfer.

Locations

PA (1)