Edentulism
Conditions
Keywords
mandibular denture instability, poor denture retention, implant-retained overdenture
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.
Detailed description
Eligible completely edentulous adults will be randomized to receive either one endosseous implant in the mandibular parasymphyseal or canine region on the preferred chewing side or two endosseous implants in the mandibular interforaminal region, followed by restoration with a locator-type attachment retained mandibular overdenture. Oral health-related quality of life, patient satisfaction, and masticatory performance assessed by a two-color chewing gum mixing test are collected at baseline before surgery and at 3, 6, and 12 months after overdenture insertion. Secondary outcomes include postoperative pain recorded during the early postoperative period, radiographic marginal bone level change, peri-implant clinical parameters, prosthetic maintenance events, and clinician chair time from implant surgery through overdenture insertion.
Interventions
PROCEDURESingle-implant mandibular overdenture (parasymphyseal/canine region)
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.
PROCEDURETwo-implant mandibular overdenture (interforaminal)
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.
Sponsors
Rola Shadid
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
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.
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 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 criteria
* 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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline in masticatory performance measured by two-color chewing gum mixing test (Variance of Hue [VoH]) | Baseline (pre-surgery), 3 months after overdenture insertion, 6 months after overdenture insertion, and 12 months after overdenture insertion. | 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). |
| Change from baseline in Oral Health Impact Profile for Edentulous Adults (OHIP-EDENT) total score | Baseline (pre-surgery), 3 months after overdenture insertion, 6 months after overdenture insertion, and 12 months after overdenture insertion | 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). |
| Change from baseline in McGill Denture Satisfaction Questionnaire (MDSQ) total score | Baseline (pre-surgery), 3 months after overdenture insertion, 6 months after overdenture insertion, and 12 months after overdenture insertion. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Marginal bone level (MBL) change around implants (mm) | Overdenture insertion (baseline), 3 months after overdenture insertion, and 12 months after overdenture insertion | Marginal bone level (MBL) will be measured on standardized periapical radiographs as the vertical distance (mm) from the implant platform to the first bone-to-implant contact at the mesial and distal aspects; for each implant and timepoint, mean MBL will be calculated as the average of mesial and distal measurements, and mean MBL change (mm) will be computed as the follow-up mean MBL minus the baseline mean MBL. |
| Implant survival | Up to 12 months after overdenture insertion. | Presence of implant in situ without removal. |
| Modified plaque index (mPI) | 3 months and 12 months after overdenture insertion. | Peri-implant plaque will be assessed at 4 sites/implant (mesial, distal, buccal, lingual) using a periodontal probe by visual inspection along abutment surfaces and scored using the Mombelli modified plaque index (0-3): 0 = no plaque; 1 = plaque detected on probing; 2 = plaque visible to the naked eye; 3 = abundance of soft matter; the implant-level outcome will be the mean of the four site scores per implant at each timepoint. |
| Bleeding on probing (BOP) per implant (%) | Baseline (at overdenture insertion), 3 months after overdenture insertion, 12 months after overdenture insertion. | BOP will be recorded at 4 sites/implant (mesial, distal, buccal, lingual) as present/absent after gentle probing; the implant-level outcome is the percentage of bleeding sites per implant (0-100%) at each timepoint. |
| Prosthetic maintenance events and complications of implant-retained overdenture | Up to 12 months after overdenture insertion. | Number and type of prosthetic maintenance events and complications related to the mandibular implant-retained overdenture recorded from clinical charts through 12 months after overdenture insertion. Events will be summarized as (a) total number of events per participant and (b) number of participants with ≥1 event. Higher values indicate worse outcome (greater maintenance/complication burden). |
| Peri-implant probing depth (PPD), mean per implant (mm) | Baseline (at overdenture insertion), 3 months after overdenture insertion, 12 months after overdenture insertion. | PPD will be measured at 4 sites/implant (mesial, distal, buccal, lingual) with a periodontal probe as the distance (mm) from the peri-implant mucosal margin to the base of the peri-implant sulcus; the implant-level outcome will be the mean of the four site measurements at each timepoint. |
| Treatment efficiency: total clinician chair time | From implant surgery through overdenture insertion. | Total clinician chair time (minutes) for surgical and prosthodontic procedures required to deliver the implant-retained mandibular overdenture. Lower values indicate greater treatment efficiency. |
| Visual Analog Scale (VAS) for postoperative pain | 24 hours after implant surgery, 7 days after implant surgery, and 21 days after implant surgery. | Postoperative pain/discomfort will be measured using a Visual Analog Scale (VAS). The VAS has an intensity range from 0 to 100, where 0 indicates "no pain" and 100 indicates "worst pain." Higher VAS scores indicate worse outcome (greater postoperative pain/discomfort). |
| 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). | Patient-reported treatment burden will be assessed using the Expected and Perceived Treatment Burden Questionnaire (20 items rated on a 4-point Likert scale: 1 = not burdensome at all to 4 = extremely burdensome); overall and stage-specific burden scores will be calculated as the mean item score (range 1-4), where higher scores indicate greater burden (worse outcome), and an expectation-perception discrepancy will be calculated for each stage as perceived burden - expected burden (positive values indicate greater burden than expected). |
Countries
Palestinian Territories
Contacts
CONTACTRola M Shadid, BDS, MSc
CONTACTJafar AbuAssba, BDS, MSc
PRINCIPAL_INVESTIGATORRola M Shadid, BDS, MSc
Arab American University
Outcome results
None listed