Comparison Physiological Tooth Mobility and Retention Success in Patients Using Different Retainers

August 30, 2026 updated by: gulden karabiber, Marmara University
The purpose of this prospective clinical study is to comparatively evaluate the long-term stability of teeth, physiological tooth mobility, and effects on periodontal tissues of three different fixed lingual retainer materials used to prevent relapse following orthodontic treatment. A total of 80 participants whose orthodontic treatment is completed will be randomly and equally distributed into four groups as one control (n=20) and three study groups (n=20 each): Group 1 will receive CAD/CAM-fabricated 0.016-inch Nitinol wire; Group 2 will receive manually bent multi- strand 0.0215-inch stainless steel wire; and Group 3 will receive 0.030-inch stainless steel chain retainers. Control group will be 20 samples. Clinical and radiographic measurements will be performed at the day of debonding (T0) and at a 6-month follow-up (T1). Physiological tooth mobility will be measured objectively using a Periotest device. Relapse amounts will be assessed by superimposing intraoral digital scans via Nemocast software using Little's Irregularity Index, and the 6-month failure/breakage rates of the retainers will be recorded. The null hypothesis states that there is no statistically significant difference among the different retainer materials regarding tooth stability, relapse, and physiological mobility.

Study Overview

Study Type

Observational

Enrollment (Estimated)

80

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Healthy volunteers whose orthodontic treatment finalized and who waited for taking off braces.

Description

Inclusion Criteria:

  1. Patients who have undergone fixed orthodontic treatment at the Department of Orthodontics, Faculty of Dentistry, Marmara University, and whose treatment is nearing completion
  2. Patients whose treatment duration is between 2 and 3 years
  3. Patients with healthy periodontal tissue (plaque index and gingival index <1; bleeding on probing <10 per cent; no clinical attachment loss)
  4. Patients aged between 18 and 35
  5. Systemically healthy individuals
  6. Patients with deep bite for whom Nitinol wire retainers, manufactured using CAD/CAM technology and capable of being fitted without occlusal contact due to their adaptability to the occlusion, have been applied
  7. Patients for whom impressions cannot be taken to fabricate a retainer
  8. Patients without deep bite or a gag reflex who have had a standard retainer fitted

Exclusion Criteria:

  1. Patients who have undergone orthodontic treatment at another clinic
  2. Patients whose treatment lasted longer than 3 years or less than 2 years
  3. Patients with a cleft lip and palate or a related syndrome
  4. Patients with caries or dental prostheses on the teeth where the retainer is to be bonded
  5. Smokers
  6. Individuals with missing anterior teeth
  7. Individuals taking systemic medication that affects the immune system or may affect periodontal health (e.g. steroids)
  8. Pregnant or breastfeeding women

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
1. Control
healthy gingiva, no smoking, non-pregnant, age:18-35, patients did not receive any orthodontic treatment and don't have bruxism and syndrome
T0 Mobility measurement with Periotest device after orthodontic treatment finished; before retainer simantation and after simantation. T1 Mobility measurement with Periotest device 6 months later; with retainer and without retainer.
T0 digital dental models will be taken with 3D scanner after orthodontic treatment finished; after retainer simantation. T1 digital dental models will be taken 6 months later with retainer. And Little irregularity index, arch length measurement will be performed.
2. CAD-CAM Nitinol wire (Memotain)
Just finished orthodontic treatment, healthy gingiva, no smoking, non-pregnant, age:18-35, patients don't have bruxism and syndrome
T0 Mobility measurement with Periotest device after orthodontic treatment finished; before retainer simantation and after simantation. T1 Mobility measurement with Periotest device 6 months later; with retainer and without retainer.
T0 digital dental models will be taken with 3D scanner after orthodontic treatment finished; after retainer simantation. T1 digital dental models will be taken 6 months later with retainer. And Little irregularity index, arch length measurement will be performed.
3. Manually bent 6 multi- strand 0.0215-inch stainless steel wire
Just finished orthodontic treatment, healthy gingiva, no smoking, non-pregnant, age:18-35, patients don't have bruxism and syndrome
T0 Mobility measurement with Periotest device after orthodontic treatment finished; before retainer simantation and after simantation. T1 Mobility measurement with Periotest device 6 months later; with retainer and without retainer.
T0 digital dental models will be taken with 3D scanner after orthodontic treatment finished; after retainer simantation. T1 digital dental models will be taken 6 months later with retainer. And Little irregularity index, arch length measurement will be performed.
4. 0.030-inch stainless steel chain
Just finished orthodontic treatment, healthy gingiva, no smoking, non-pregnant, age:18-35, patients don't have bruxism and syndrome
T0 Mobility measurement with Periotest device after orthodontic treatment finished; before retainer simantation and after simantation. T1 Mobility measurement with Periotest device 6 months later; with retainer and without retainer.
T0 digital dental models will be taken with 3D scanner after orthodontic treatment finished; after retainer simantation. T1 digital dental models will be taken 6 months later with retainer. And Little irregularity index, arch length measurement will be performed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Tooth mobility
Time Frame: From enrollment to the end of treatment at 6 months
Tooth mobility will be assessed using the Periotest device. The device will be applied to the buccal surface of the tooth, and the Periotest value (PTV) will be recorded according to the manufacturer's instructions. Higher PTV values indicate greater tooth mobility. Measurements will be recorded as Periotest values (PTV).
From enrollment to the end of treatment at 6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Little irregularity
Time Frame: From enrollment to the end of treatment at 6 months
Anterior dental irregularity will be assessed using Little's Irregularity Index, measured as the sum of the five linear displacements between the anatomic contact points of the mandibular anterior teeth, in millimeters (mm). This assessment will be performed on digital intraoral models by using Orthomodel (Orthomodel, İstanbul, Türkiye) software.
From enrollment to the end of treatment at 6 months
Arch length
Time Frame: From enrollment to the end of treatment at 6 months
Dental arch length will be assessed by measuring the linear distance from the midpoint between the central incisors to a line connecting the distal surfaces of the first permanent molars, in millimeters (mm). This assessment will be performed on digital intraoral models by using Orthomodel (Orthomodel, İstanbul, Türkiye) software.
From enrollment to the end of treatment at 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 15, 2026

Primary Completion (Estimated)

January 1, 2027

Study Completion (Estimated)

March 1, 2027

Study Registration Dates

First Submitted

July 19, 2026

First Submitted That Met QC Criteria

August 30, 2026

First Posted (Actual)

September 3, 2026

Study Record Updates

Last Update Posted (Actual)

September 3, 2026

Last Update Submitted That Met QC Criteria

August 30, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • GKAY-ret

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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