An interventional study of Conventional Multistranded Stainless Steel Fixed Retainer and 3D-Printed Cobalt-Chromium Fixed Retainer in Orthodontic Relapse and Malocclusion, sponsored by Minia University. Not yet recruiting. Open to participants aged 21 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-31.
Sponsored by Minia University · Not applicable, Interventional, and Treatment
This randomized clinical trial aims to compare the clinical performance of two types of three-dimensionally printed fixed retainers (Cobalt-Chromium and Titanium Grade 5) with the conventional multistranded stainless steel fixed retainer following orthodontic treatment. Thirty-six participants will be randomly allocated into three parallel groups with a 1:1:1 allocation ratio. The primary outcome is post-treatment stability assessed by Little's Irregularity Index and lower arch dimensions. Secondary outcomes include bond failure rate and periodontal parameters over a 12-month follow-up period.
Orthodontic relapse remains one of the greatest challenges following the completion of orthodontic treatment. Conventional multistranded stainless steel fixed retainers are considered the gold standard for long-term retention; however, they have several limitations, including operator-dependent adaptation, prolonged chairside time, structural instability, and possible unwanted tooth movement.
Advances in digital dentistry have introduced CAD/CAM technology and additive manufacturing (3D printing), enabling the fabrication of customized fixed retainers with improved adaptation and manufacturing accuracy. Three-dimensional printed retainers fabricated from Cobalt-Chromium (Co-Cr) and Titanium Grade 5 (Ti-6Al-4V) alloys may provide superior mechanical properties, greater manufacturing precision, and potentially improved clinical performance compared with conventional retainers.
323 studies on the registry are indexed under Malocclusion; 85 are open to participants now.
This study's planned enrollment of 36 is close to the median of 37 across 242 interventional studies indexed under Malocclusion.
Browse Malocclusion studies →Minia University is the lead sponsor of 370 studies on the registry; 117 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
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Exclusion Criteria:
Participants receive a conventional multistranded stainless steel fixed retainer bonded after orthodontic debonding.
Device: Conventional Multistranded Stainless Steel Fixed Retainer
Participants receive a customized 3D-printed cobalt-chromium fixed retainer bonded after orthodontic debonding
Device: 3D-Printed Cobalt-Chromium Fixed Retainer
Participants receive a customized 3D-printed titanium (Ti-6Al-4V) fixed retainer bonded after orthodontic debonding.
Device: 3D-Printed Titanium Fixed Retainer
Conventional 0.0215-inch six-stranded stainless steel bonded fixed retainer.
Customized 3D-printed cobalt-chromium bonded fixed retainer fabricated from intraoral scans.
Customized 3D-printed titanium (Ti-6Al-4V) bonded fixed retainer fabricated from intraoral scans.
Orthodontic stability assessed using Little's Irregularity Index
Orthodontic stability will be assessed using Little's Irregularity Index on digital models. The Little's Irregularity Index ranges from 0 mm to higher positive values. A score of 0 mm indicates perfect alignment. Higher scores indicate greater relapse, whereas lower scores indicate better orthodontic stability.
Time frame: 12 months
Retainer failure rate
Assessment of the failure rate of conventional stainless steel, 3D-printed cobalt-chromium, and 3D-printed titanium fixed retainers.
Time frame: 12 months
Plaque Index (Silness and Löe Plaque Index)
Dental plaque accumulation will be assessed using the Silness and Löe Plaque Index, which is scored from 0 to 3: 0: No plaque 1. A film of plaque detectable by probe 2. Moderate plaque accumulation 3. Abundant plaque accumulation Lower scores indicate better oral hygiene.
Time frame: 12 months
Gingival Index (Löe and Silness Gingival Index)
Gingival inflammation will be assessed using the Löe and Silness Gingival Index, which is scored from 0 to 3: 0: Normal gingiva 1. Mild inflammation 2. Moderate inflammation 3. Severe inflammation Lower scores indicate better gingival health.
Time frame: 12 months
Bleeding on Probing (BOP)
Assessment of bleeding on probing as an indicator of gingival inflammation. Bleeding on probing will be assessed as the percentage of bleeding sites (0-100%). Lower percentages indicate better periodontal health.
Time frame: 12 months
Probing Pocket Depth (PPD)
Assessment of periodontal pocket depth using a periodontal probe. Pocket depth will be recorded in millimeters (mm). Lower values indicate better periodontal health.
Time frame: 12 months
No study locations are listed for this record.
Plan to share: No — No plan to share individual participant data (IPD).
No publications or documents are linked to this record.
Start is estimated for Aug 2026; primary completion for Aug 2027, 12 months later.
Of 153 non-industry interventional studies with no phase under Malocclusion, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 30. This study's planned 12 months is below that.
Counting every sponsor, half of 163 studies reached it within 19 months; a quarter within 10 and three quarters within 32.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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