An interventional study of Cobalt-Chromium Bar Attachment and Zirconia CAD/CAM Bar Attachment in Edentulous Mandible, sponsored by Sara Mohamed Fakhry Meligy Mohamed. Completed at 1 site in Egypt. Open to male participants aged 50 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-24.
Sponsored by Sara Mohamed Fakhry Meligy Mohamed · Not applicable, Interventional, and Treatment
This randomized clinical trial aimed to evaluate the radiographic and clinical evaluations of mandibular implant-supported overdentures supported d by two different bar materials。 Completely edentulous patients received two implants in the mandibular canine region and were rehabilitated with overdentures supported by a conventional cobalt-chromium bar and a zirconia CAD/CAM bar。 Radiographic marginal bone loss around implants, crestal bone height changes posteriorly and clinical peri-implant parameters were assessed at baseline,6 months, and 12 months to compare the performance of both bar materials。
This randomized clinical trial was conducted to compare the radiographic and clinical outcomes of mandibular implant-supported overdentures supported by conventional cobalt-chromium bars and zirconia CAD/CAM bars。 Eligible completely edentulous patients were selected according to predefined inclusion and exclusion criteria。
All participants received two endosseous dental implants placed in the mandibular canine regions following a standardized surgical protocol。 After a healing period, patients were randomly allocated into two groups。 In the first group, overdentures were supported by using a conventional cast cobalt-chromium bar, while in the second group, overdentures were supported by using a zirconia CAD/CAM-fabricated bar。
Radiographic evaluations of marginal bone loss around implants and crestal bone height changes posteriorly were performed using cone beam computed tomography and clinical peri-implant parameters, including pocket depth, plaque index, bleeding index, and mobility were evaluated at baseline,6 months and after 12 months。
The primary outcome of this study was the evaluation of radiographic marginal bone loss around implants and crestal bone height changes posteriorly, while secondary outcomes included peri-implant soft tissue health parameters。 The collected data were statistically analysed to compare bone stability and clinical performance associated with the two bar materials over the observation period。
This is the only study on the registry with Sara Mohamed Fakhry Meligy Mohamed as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Patients age range was between 50-60 years old.
Exclusion Criteria:
Patients with systemic diseases that might affect bone quality, contribute to bone resorption, increase surgical risk, or delay/complicate post-operative healing.
participants received mandibular implant-supported overdentures supported by a conventional cast cobalt-chromium bar
Device: Cobalt-Chromium Bar Attachment
participants received mandibular implant-supported overdentures supported by a Zirconia CAD/CAM-fabricated bar
Device: Zirconia CAD/CAM Bar Attachment
A conventional cast cobalt-chromium bar used to retain a mandibular implant-supported overdenture
A zirconia CAD/CAM-fabricated bar used to retain a mandibular implant-supported overdenture
Marginal bone loss around Implants
Radiographic assessment of marginal bone loss around mandibular implants and crestal bone height changes posteriorly using cone-beam computed tomography (CBCT)
Time frame: Baseline,6 months, and 12 months
Posterior crestal bone height changes of the mandibular ridge
Radiographic assessment of posterior crestal bone height changes of the mandibular ridge using cone-beam computed tomography (CBCT)
Time frame: Baseline,6months,12months
Peri-Implant probing depth
Peri-implant probing depth measured using a calibrated periodontal probe
Time frame: Baseline,6 months, and 12 months
plaque index around implants
Plaque accumulation around implants assessed using Silness and Löe plaque index
Time frame: Baseline, 6 months, and 12 months
Bleeding on probing around implants
Bleeding on probing around implants assessed using a calibrated periodontal probe
Time frame: Baseline, 6 months, and 12 months
Implant mobility
Implant mobility evaluated using clinical manual assessment (two rigid instrument technique)
Time frame: Baseline, 6 months, and 12 months
Plan to share: No
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This study is completed, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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