An interventional study of Experimental: Single strand β-Ti fixed retainer and Experimental: SS fixed retainer in Relapse and Orthodontic Retention, sponsored by University of Athens. Active, not recruiting at 1 site in Greece. Open to participants aged 13 Years to 30 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-01-06.
Sponsored by University of Athens · Not applicable, Interventional, and Treatment
There is high possibility of relapse of the lower anterior teeth after orthodontic treatment. Relapse is related with the initial orthodontic anomaly, pathology of surrounding tissues, patient's age and sex and compliance and the retention protocol applied. The options for the later are various. Permanent fixed retainers are considered of the most common ones and vastly vary based of composition. There are fixed retainers distinguished for their composition (SS, β-NiTi, fiber-reinforced composite retainers) or for their shape and dimensions (round or rectangular shape and single-strand or multi-strand respectively), and/or for the teeth they are placed on (canine and canine or canine to canine). Fixed retainers may require patient's cooperation , nevertheless debond failure rate varies between 0.1-53%.
The aim of this prospective randomized clinical study is to compare failure incidents and retention effect on lower anterior teeth after orthodontic finish between three different types of fixed retainers. There will be 3 arms studied in this research: a) single strand 0.016x0.022'' β-Ti canine to canine, b) 0.028'' SS canine to canine and c) 0.027'' multi-strand twistflex canine to canine. Variables such as repeatability of failures, and undesired tooth movements will be measured. Measurements will be repeated every 3 months after patient's recruitment in this study, for one year period (12 months in total). Intraoral scans will be collected during baseline (fixed retainer insertion) and after 12 months.
4,279 studies on the registry are indexed under Recurrence; 987 are open to participants now.
This study's planned enrollment of 90 is above the median of 50 across 3,373 interventional studies indexed under Recurrence.
Browse Recurrence studies →University of Athens is the lead sponsor of 133 studies on the registry; 19 are open to participants now.
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Exclusion Criteria:
Single strand β-Ti fixed retainer 0.011in diameter, bonded on each tooth separately from #33-43
Device: Experimental: Single strand β-Ti fixed retainer
SS fixed retainer 0.028in diameter, bonded on each tooth separately from #33-43
Device: Experimental: SS fixed retainer
Twisted fixed retainer 0.027in diameter, bonded on each tooth separately from #33-43
Device: Experimental: Twisted fixed retainer
All 90 patients between 13-30 y.o. treated with fixed orthodontic appliances (Roth 0.018'' slot at their final finishing stage) on at least between their lower first premolars and with no lower anterior teeth crowding (total irregularity index score = 0) and no need of removable retention appliances on their lower teeth, were randomly assigned to one of the three experimental groups.
All 90 patients between 13-30 y.o. treated with fixed orthodontic appliances (Roth 0.018'' slot at their final finishing stage) on at least between their lower first premolars and with no lower anterior teeth crowding (total irregularity index score = 0) and no need of removable retention appliances on their lower teeth, were randomly assigned to one of the three experimental groups.
All 90 patients between 13-30 y.o. treated with fixed orthodontic appliances (Roth 0.018'' slot at their final finishing stage) on at least between their lower first premolars and with no lower anterior teeth crowding (total irregularity index score = 0) and no need of removable retention appliances on their lower teeth, were randomly assigned to one of the three experimental groups.
Number of teeth that failed regarding the bonding strength
Time frame: baseline-3 months
Number of teeth that failed regarding the bonding strength
Time frame: 3 months-6 months
Number of teeth that failed regarding the bonding strength
Time frame: 6 months-9 months
Number of teeth that failed regarding the bonding strength
Time frame: 9 months-1 year
Repeatability of bonding strength failure per patient and per tooth
Time frame: baseline-3 months
Repeatability of bonding strength failure per patient and per tooth
Time frame: 3 months-6 months
Repeatability of bonding strength failure per patient and per tooth
Time frame: 6 months-9months
Repeatability of bonding strength failure per patient and per tooth
Time frame: 9months-1 year
Breakage of fixed retainer wires
Time frame: baseline-3 months
Breakage of fixed retainer wires
Time frame: 3 months-6 months
Breakage of fixed retainer wires
Time frame: 6 months-9 months
Breakage of fixed retainer wires
Time frame: 9 months-1 year
Space discrepancy (Little index)(in mm)
Time frame: baseline-3 months
Space discrepancy (Little index)(in mm)
Time frame: 3 months-6 months
Space discrepancy (Little index)(in mm)
Time frame: 6 months-9 months
Space discrepancy (Little index)(in mm)
Time frame: 9 months-1 year
Mandibular intercanine distance
Time frame: baseline-3 months
Mandibular intercanine distance
Time frame: 3 months-6 months
Mandibular intercanine distance
Time frame: 6 months-9 months
Mandibular arch length (in mm)
Time frame: 9 months-1 year
Tooth rotations in lower anterior teeth
Time frame: baseline-3 months
Tooth rotations in lower anterior teeth
Time frame: 3 months-6 months
Tooth rotations in lower anterior teeth
Time frame: 6 months-9 months
Tooth rotations in lower anterior teeth
Time frame: 9 months-1 year
Extrusion in lower anterior teeth
Time frame: baseline-3 months
Extrusion in lower anterior teeth
Time frame: 3 months-6 months
Extrusion in lower anterior teeth
Time frame: 6 months-9 months
Extrusion in lower anterior teeth
Time frame: 9 months-1 year
Tip inclinations anteroposteriorly
Time frame: baseline-3 months
Tip inclinations anteroposteriorly
Time frame: 3 months-6 months
Tip inclinations anteroposteriorly
Time frame: 6 months-9 months
Tip inclinations anteroposteriorly
Time frame: 9 months -1 year
Plan to share: No
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University of Athens