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The Effect of Full Versus Partial Coverage Thermoformed Retainers in Dual Retention With a Lower Bonded Retainer, on Periodontal, Orthodontic, and Patient-Reported Outcomes

The Effect of Full Versus Partial Coverage Thermoformed Retainers in Dual Retention With a Lower Bonded Retainer, on Periodontal, Orthodontic, and Patient-Reported Outcomes: A Randomised Controlled Trial

Status
Not yet recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07669129
Enrollment
42
Registered
2026-06-25
Start date
2026-07-01
Completion date
2027-09-30
Last updated
2026-07-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Orthodontic Retention

Keywords

Orthodontic retention, clear retainer, fixed bonded retainer, periodontal health, breakage

Brief summary

After braces are removed, teeth may move back toward their original positions. Retainers are used to help keep teeth straight after orthodontic treatment. This study compares two types of clear removable retainers used together with a fixed wire retainer behind the lower front teeth. One retainer covers the entire inner surface of the teeth (full coverage), while the other covers only part of the inner surface (partial coverage). The purpose of this study is to find out whether the two retainer designs differ in their effects on gum health, comfort, retainer breakages, stability of the orthodontic correction, comfort, and compliance. The findings from this study may help orthodontists choose the most suitable retainer design for future patients. Participants in this study will receive a fixed wire retainer on the lower front teeth and upper and lower clear removable retainers. They will be randomly assigned to receive either the full coverage or partial coverage lower retainer. Participants will attend follow-up visits at 1 month, 3 months, and 6 months after starting retainer wear. At these visits, the orthodontist will examine the teeth, gums, and retainers, and participants will complete a short questionnaire about their experience wearing the retainer. This study excluded participants who are pregnant or breastfeeding within the first 6 months, have uncontrolled medical conditions or gum disease, smoke or vape, require a Hawley retainer instead of a clear retainer, or have missing front teeth or certain jaw conditions. Participants may benefit from receiving retainers, oral hygiene care, and regular monitoring of their teeth and gum health at no additional cost. Participants will also receive an oral care kit during the debond appointment and at the 3-month and 6-month review visits. Possible risks include breakage of the retainers, which may require repair or replacement, gum problems if oral hygiene is not maintained, and slight tooth movement despite retainer use. If gum problems develop, appropriate cleaning and referral for further treatment may be provided. Replacement retainers required during the study period will be provided free of charge.

Detailed description

Vivera retainers will be the only thermoformed retainers used throughout this study.

Interventions

DEVICEPartial coverage vivera retainer

A removable lower retainer (Vivera retainer) with partial coverage design which covers part of the inside surface of lower teeth excluding the fixed bonded retainer

DEVICEFull coverage Vivera retainer

A removable lower retainer (Vivera retainer) with full coverage design which covers the entire inside surface of lower teeth including the fixed bonded retainer

Sponsors

University of Malaya
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Aged over 18 years. * Controlled systemic diseases and conditions. * Probing pocket depth ≤ 3 mm * Bleeding on probing \< 10 per cent * Full mouth plaque scores of less than 20 per cent * Just completed active orthodontic treatment involving lower arch * Patient consent to dual retention in the lower arch

Exclusion criteria

* Require a Hawley retainer in the lower arch. * Patients in retention phase requiring replacement of retainers * Uncontrolled systemic disease, including chronic or metabolic diseases. * Pregnant or lactating mothers within six months postpartum. * Taking medications that affect gingival health and architecture. * Have one or more missing anterior teeth. * Have congenital craniofacial deformities and syndromes, including cleft lip and/ or palate * Cigarette or vape smokers

Design outcomes

Primary

MeasureTime frameDescription
Full mouth plaque scorebaseline, 1 month, 3 months and 6 monthsTo evaluate full mouth plaque score associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch. Scale title: Full mouth plaque score Minimum value: 0% Maximum value: 100% Higher score means indicate worse plaque accumulation and poorer oral hygiene. (worse outcome)
Full mouth bleeding on probing scoreBaseline, 1 month, 3 months and 6 monthsTo evaluate full mouth bleeding on probing score associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch. Scale title: Full mouth bleeding on probing score Minimum value: 0% Maximum value: 100% Higher score means indicate worse periodontal health (worse outcome)
Periodontal probing depth of lower anterior teethbaseline, 1 month, 3 months and 6 monthsTo evaluate periodontal probing depth of lower anterior teeth associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch Scale title: Periodontal probing depth Minimum value: 0mm Maximum value: No fixed upper limit Higher score means indicate worse periodontal health (worse outcome)
Gingival recession on lower anterior teethBaseline, 1 month, 3 months and 6 monthsTo evaluate gingival recession on lower anterior teeth associated with clear retainers with partial or full coverage designs when used in conjunction with fixed bonded retainers in the lower arch Scale title: Gingival recession Minimum value: 0mm Maximum value: No fixed upper limit Higher score means indicate worse periodontal health (worse outcome)
Integrity of clear retainer3 months and 6 monthsTo evaluate the incidence of clear retainer breakages associated with partial or full coverage designs when used in combination with fixed bonded retainers in the lower arch
Breakages of fixed bonded retainers1 month, 3 months, 6 monthsTo evaluate the incidence of breakages involving bonded wire or adhesive resin of fixed bonded retainers when used in combination with clear retainers in either partial or full coverage designs in the lower arch.

Secondary

MeasureTime frameDescription
Stability of lower anterior teethBaseline, 3 months, 6 monthsTo evaluate the stability of lower anterior teeth (using Little's Irregularity Index) associated with partial and full coverage designs of clear retainers when used in conjunction with fixed bonded retainers. Scale title: Little's Irregularity Index Minimum value: 0mm Maximum value: No fixed upper limit Higher scores indicate greater relapse and worse alignment. (worse outcome)
Quality of Life in Patients Wearing Orthodontic Retainers3 months and 6 monthsTo evaluate the patient's quality of life associated with partial or full coverage designs of clear retainers when used in conjunction with fixed bonded retainers. Quality of life assessed using the Quality of Life in Patients Wearing Orthodontic Retainers questionnaire. Total scores range from 0 score to 56 score, with higher scores indicating poorer quality of life related to retainer wear.
Patient's compliance3 months and 6 monthsPatient compliance associated with partial or full coverage clear retainers used in conjunction with fixed bonded retainers will be evaluated using Part B, Questions 1 and 2 of the Quality of Life in Patients Wearing Orthodontic Retainers questionnaire. Compliance will be reported as "yes" or "no." For non-compliance responses, reasons for non-compliance will also be recorded, with multiple responses permitted.

Countries

Malaysia

Contacts

CONTACTZHI MEI CHIA
s2102418@siswa.um.edu.my+60143438922

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 24, 2026