Plain English Summary
Background and study aims
Following orthodontic brace treatment the teeth are held in their new position by orthodontic appliances called retainers. One type of retainer is called a bonded retainer which is a small metal wire glued behind the front teeth. This study is looking at the use of two different types of bonded retainer to find out which is better: one that is shaped by the orthodontist, or one that has been made from a mould of the teeth by a computer. The study looks at which holds the teeth in their new position the best, which patients prefer and which is the most cost effective.
Who can participate?
Participants who have undergone a course of orthodontic treatment and who now require a retainer
What does the study involve?
Participants are randomly allocated to one of two groups to be treated with either a Memotain bonded retainer or an Ortho FlexTech bonded retainer. Participants are followed up over a 5-year period to determine the effectiveness of the retainers at maintaining the stability of the teeth after orthodontic treatment.
What are the possible benefits and risks of participating?
The benefit to patients is that they are followed up for longer than normal (5 years). The study will help to show the best type of retainer for certain patients. The current research suggests there are no associated risks with wearing retainers.
Where is the study run from?
1. Leeds Dental Institute (UK)
2. St Luke's Hospital (UK)
3. Beverley Orthodontic Centre (UK)
When is the study starting and how long is it expected to run for?
September 2017 to September 2023
Who is funding the study?
1. Investigator initiated and funded
2. National Institute for Health Research (NIHR) (additional funding) (UK)
Who is the main contact?
1. Adam Jowett
2. Simon Littlewood
Trial website
Contact information
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
Protocol Number: DT16/86705, IRAS Number: 185443, REC Number 16/YH/0463.
Study information
Scientific title
CAD/CAM nitinol bonded retainer versus a chairside bonded retainer: a multicentre randomised controlled trial
Acronym
Study hypothesis
Null hypothesis: There is no significant difference in stability, survival rate, patient satisfaction, and cost-effectiveness between using a CAD/CAM nitinol bonded retainer (Memotain) and a chairside bonded retainer (Ortho FlexTech).
Ethics approval
Yorkshire & The Humber - Bradford Leeds Research Ethics Committee, 07/07/2017, REC ref: 16/YH/0463, protocol number: DT16/86705
Study design
Multicentre prospective two-arm parallel-group randomised controlled trial with a 1:1 allocation
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Other
Trial type
Treatment
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Condition
Orthodontic relapse
Intervention
Simple randomisation will be used to allocate patients to one of the two groups. The randomisation website: www.sealedenvelope.com will be used to allocate patients to treatment group 1 or group 2. Block sizes of 2, 4 and 6 will be used.
Group 1: Memotain bonded retainer
Group 2: Ortho FlexTech bonded retainer
Patients are followed up to determine the efficacy of a CAD/CAM nitinol bonded retainer (Memotain) compared with a chairside bonded retainer (Ortho FlexTech) at maintaining the stability of the upper and lower arches after orthodontic treatment.
Intervention type
Device
Phase
Drug names
Primary outcome measure
Stability measured by changes in Little's Irregularity Index, and the width of the upper and lower dental arches measured by inter-canine and inter-molar width. In extraction cases, the trialists will also assess whether or not the extraction space re-opens. These measurements will be carried out on orthodontic study models taken at the debond appointment, and the 6 month, 1 year, 2 year and 5 year review appointments.
Secondary outcome measures
Assessed at the 6 week, 6 month, 1 year, 2 year and 5 year review appointments:
1. The survival rate of each retainer type
2. The patient satisfaction with each retainer type
Assessed at the 1 year and 5 year review appointments:
1. The cost-effectiveness of each retainer type
Overall trial start date
12/09/2017
Overall trial end date
11/09/2025
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
Each subject will:
1. Have undergone a course of upper and lower fixed appliance orthodontic treatment with satisfactory correction of the presenting malocclusion, where the treating clinician feels that retention is required
2. Have a full and normal complement of teeth in the upper and lower labial segments (incisors and canines) with these teeth being of normal size and shape
3. Brush their teeth at least twice per day
4. Be in good health
5. Be willing and able to comply with the trial regime
6. Have given written informed consent
Subjects may:
1. Have received treatment at any of the research sites
2. Have had dental extractions (premolar or molar) or a non-extraction approach
3. Have had other orthodontic treatment (e.g. removable or functional appliances) as part of their orthodontic treatment
4. Have undergone adjunctive surgical treatment, whether minor oral surgery to expose a tooth or orthognathic surgery to correct the position of the jaws
Participant type
Patient
Age group
All
Gender
Both
Target number of participants
100 patients (50 patients per arm)
Participant exclusion criteria
Subjects with:
1. Nickel allergy
2. Cleft palate and/or other severe facial deformity
3. Poor periodontal health including the presence of supragingival or subgingival calculus or periodontal pocketing greater than 3.5mm as determined by a basic periodontal examination (BPE) probe
4. Gross or uncontrolled caries
5. Prosthodontic requirement in the upper or lower arch at end of treatment
6. Restorations on the palatal/lingual surfaces of upper or lower incisors or canines
7. A starting malocclusion requiring extreme transverse correction
Recruitment start date
20/10/2017
Recruitment end date
11/09/2019
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Leeds Dental Institute (University Dental Hospital)
The Worsley Building
Clarendon Way
Leeds
LS2 9LU
United Kingdom
Trial participating centre
St Luke's Hospital (District General Hospital)
Little Horton Lane
Bradford
BD5 0NA
United Kingdom
Trial participating centre
Beverley Orthodontic Centre (Specialist Orthodontic Practice)
114 Norwood
Beverley
HU17 9HL
United Kingdom
Sponsor information
Organisation
Leeds Dental Institute
Sponsor details
Worsley Building
Clarendon Way
Leeds
LS2 9LU
United Kingdom
+44 (0)113 3434897
governance-ethics@leeds.ac.uk
Sponsor type
Hospital/treatment centre
Website
Funders
Funder type
Other
Funder name
Investigator initiated and funded
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Funder name
National Institute for Health Research (NIHR) (additional funding)
Alternative name(s)
NIHR
Funding Body Type
government organisation
Funding Body Subtype
Federal/National Government
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal in late 2020.
IPD sharing statement
The datasets generated and/or analysed during the current study will be included in the subsequent results publication.
Intention to publish date
11/09/2026
Participant level data
Other
Basic results (scientific)
Publication list