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

Summary

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.

Conditions

• Relapse
• Orthodontic Retention

Interventions

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.

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.

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.

Sponsors & Collaborators

• University of Athens

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

13 Years

Max Age

30 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-01-16

Primary Completion

2025-06-30

Completion

2025-11-30

Countries

• Greece

Study Locations