Single-implant Versus Two-implant Mandibular Overdentures
Patient-reported Outcomes and Masticatory Performance of Mandibular Overdentures Retained by One Parasymphyseal Implant or Two Implants: Randomized Clinical Trial
Rola Shadid
32 participants
Feb 16, 2026
INTERVENTIONAL
Conditions
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.
Eligibility
Inclusion Criteria10
- 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.
Exclusion Criteria14
- 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.
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Interventions
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.
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.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT07408778