The Effectiveness of 3 Orthodontic Fixed Retention Schemes on Post-treatment Stability and Gingival Recession (OrthRe10tion)

A Single-center, 3-arm, Parallel-group Randomized Controlled Trial to Evaluate Bond Failures and the Effectiveness of Three Orthodontic Retention Schemes in Preventing Post-treatment Mandibular Arch Changes

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Relapse; Orthodontic Retention
• Intervention / Treatment: Device: Experimental: Single strand β-Ti fixed retainer; Device: Experimental: SS fixed retainer; Device: Experimental: Twisted fixed retainer

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Greece
  • Attiki
    • Athens, Attiki, Greece, 11527
      • National and Kapodistrian University of Athens, School of Dentistry, Departments of Orthodontics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Patients treated with fixed orthodontic appliances (Roth 0.018'' slot at their final finishing stage)
• Patients with fixed orthodontic appliances at least between their lower first premolars
• No lower anterior teeth crowding (total irregularity index score = 0)
• Patients with no need of removable retention appliances on their lower teeth

Exclusion Criteria:

• Active caries on adjacent or lingual surfaces of lower anterior teeth
• Active periodontitis
• Supragingival calculus
• Gum bleeding during bonding of fixed retainer
• Gingival pocket depth greater than 3mm
• Syndromes or other anomalies of the craniofacial complex or other mental illness
• Missing or impacted teeth or other dental anomalies
• Congenital anomalies/syndromes
• Allergies regarding the alloys of fixed retainers
• Need for chemoprevention before data collection of periodontal indexes
• Diabetes
• Smoking
• Usage of antibiotics
• Pregnancy
• Participation in other clinical trials

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Single strand β-Ti fixed retainer; 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; 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.
Experimental: SS fixed retainer; SS fixed retainer 0.028in diameter, bonded on each tooth separately from #33-43	Device: Experimental: SS 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.
Experimental: Twisted 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of teeth that failed regarding the bonding strength	baseline-3 months
Number of teeth that failed regarding the bonding strength	3 months-6 months
Number of teeth that failed regarding the bonding strength	6 months-9 months
Number of teeth that failed regarding the bonding strength	9 months-1 year
Repeatability of bonding strength failure per patient and per tooth	baseline-3 months
Repeatability of bonding strength failure per patient and per tooth	3 months-6 months
Repeatability of bonding strength failure per patient and per tooth	6 months-9months
Repeatability of bonding strength failure per patient and per tooth	9months-1 year
Breakage of fixed retainer wires	baseline-3 months
Breakage of fixed retainer wires	3 months-6 months
Breakage of fixed retainer wires	6 months-9 months
Breakage of fixed retainer wires	9 months-1 year
Space discrepancy (Little index)(in mm)	baseline-3 months
Space discrepancy (Little index)(in mm)	3 months-6 months
Space discrepancy (Little index)(in mm)	6 months-9 months
Space discrepancy (Little index)(in mm)	9 months-1 year
Mandibular intercanine distance	baseline-3 months
Mandibular intercanine distance	3 months-6 months
Mandibular intercanine distance	6 months-9 months
Mandibular arch length (in mm)	9 months-1 year

Secondary Outcome Measures

Outcome Measure	Time Frame
Tooth rotations in lower anterior teeth	baseline-3 months
Tooth rotations in lower anterior teeth	3 months-6 months
Tooth rotations in lower anterior teeth	6 months-9 months
Tooth rotations in lower anterior teeth	9 months-1 year
Extrusion in lower anterior teeth	baseline-3 months
Extrusion in lower anterior teeth	3 months-6 months
Extrusion in lower anterior teeth	6 months-9 months
Extrusion in lower anterior teeth	9 months-1 year
Tip inclinations anteroposteriorly	baseline-3 months
Tip inclinations anteroposteriorly	3 months-6 months
Tip inclinations anteroposteriorly	6 months-9 months
Tip inclinations anteroposteriorly	9 months -1 year

Collaborators and Investigators

• Sponsor: University of Athens

Study record dates

Study Major Dates

• Study Start (Actual): January 16, 2022
• Primary Completion (Estimated): June 1, 2025
• Study Completion (Estimated): November 1, 2025

Study Registration Dates

• First Submitted: May 31, 2023
• First Submitted That Met QC Criteria: June 29, 2023
• First Posted (Actual): July 3, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 3, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Recurrence
• Other Study ID Numbers: 409/08.02.2022

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No