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

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.

Active, not recruiting

This study is active but is not currently recruiting participants.

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Key information

Conditions

Orthodontic Retainers Mouth Diseases Periodontal Diseases Stomatognathic Diseases Tooth Mobility

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Marmara University

Istanbul, 34784, Turkey (Türkiye)

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Patients who have undergone fixed orthodontic treatment at the Department of Orthodontics, Faculty of Dentistry, Marmara University, and whose treatment is nearing completion
Patients whose treatment duration is between 2 and 3 years
Patients with healthy periodontal tissue (plaque index and gingival index <1; bleeding on probing <10 per cent; no clinical attachment loss)
Patients aged between 18 and 35
Systemically healthy individuals
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
Patients for whom impressions cannot be taken to fabricate a retainer
Patients without deep bite or a gag reflex who have had a standard retainer fitted

Exclusion criteria

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

Treatment and study plan

Mobility measurement with Periotest device

Diagnostic Test

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.

Digital intraoral impression

Diagnostic Test

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.

Primary outcomes

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).

Secondary outcomes

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.
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.

Sponsors and collaborators

Lead sponsor

Marmara University

Other

Registry information

Important dates

Study start: 2026
Primary completion: 2027
Study completion: 2027
First posted: Sep 3, 2026
Registry last updated: Sep 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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