Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12622000644763
Ethics application status
Approved
Date submitted
7/04/2022
Date registered
3/05/2022
Date last updated
19/04/2023
Date data sharing statement initially provided
3/05/2022
Date results information initially provided
19/04/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Can Clear Orthodontic Retainers be Used for Tooth Whitening?
Scientific title
Can Clear Orthodontic Retainers be Used for Tooth Whitening after Completed Orthodontic Treatment?
Secondary ID [1] 306861 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
orthodontics 325953 0
Teeth discolouration 326110 0
Condition category
Condition code
Oral and Gastrointestinal 323264 323264 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A split-mouth design will be used. Participants will be randomised into two groups after the completion of orthodontic treatment. Clear orthodontic retainers will be made for both the maxillary (upper) and the mandibular (lower) arch.
Group A will receive at-home whitening treatment using 10% carbamide peroxide in the maxillary arch only.
Group B will receive at-home whitening treatment using 10% carbamide peroxide in the mandibular arch only
Participants will apply 10% carbamide peroxide in the treating arch retainer overnight (approximately 6-8 hours) daily for 2 weeks. Orthodontic postgraduate student will be administering the intervention. Patients will be reviewed 1 week, 2 week and 4 weeks after commencement to monitor adherence.
Intervention code [1] 323329 0
Treatment: Other
Comparator / control treatment
The remaining arch of the same patient will act as the control - split-mouth design. Patients will be wearing the orthodontic clear retainer but with no whitening material.
Control group
Active

Outcomes
Primary outcome [1] 331012 0
Biomechanical property change in the orthodontic clear retainers including compressive strength, tensile and surface roughness analysis. A universal mechanical testing instrument (Instron Co., Canton, MA, USA) will be used.
Timepoint [1] 331012 0
4 weeks after intervention commencement
Secondary outcome [1] 408490 0
Tooth position will be assessed by superimposing two digital scans with specialised computer software.
Timepoint [1] 408490 0
4 weeks after intervention commencement
Secondary outcome [2] 408491 0
Tooth colour will be assessed by using VitaPan tooth shade guide as well as a digital VitaEasyshade device under standard room lighting.
Timepoint [2] 408491 0
2 weeks and 4 weeks after intervention commencement

Eligibility
Key inclusion criteria
Subjects who have finished active orthodontic treatment with twelve vital anterior teeth from canine to canine with no direct or indirect restorations, no need for attachments or divots on the labial surfaces of the maxillary canines or incisors, no history of dentine hypersensitivity and no history of tooth whitening during the previous three years. If the patient is less than 16 years old, consent will be required from the parents/guardian.
Minimum age
10 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Subjects who are smokers, pregnant or breastfeeding, have active caries or periodontal disease, have severe fluorosis or tetracycline staining, or with known allergic reactions to whitening materials.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Split mouth study
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
16/05/2022
Actual
16/05/2022
Date of last participant enrolment
Anticipated
31/03/2023
Actual
9/12/2022
Date of last data collection
Anticipated
30/04/2023
Actual
14/04/2023
Sample size
Target
30
Accrual to date
Final
30
Recruitment outside Australia
Country [1] 24714 0
New Zealand
State/province [1] 24714 0
Dunedin

Funding & Sponsors
Funding source category [1] 311182 0
University
Name [1] 311182 0
Fuller Scholarship University of Otago
Country [1] 311182 0
New Zealand
Primary sponsor type
University
Name
University of Otago
Address
University of Otago, 310 Great King Street, Dunedin North, Dunedin 9016, New Zealand
Country
New Zealand
Secondary sponsor category [1] 312551 0
None
Name [1] 312551 0
Address [1] 312551 0
Country [1] 312551 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 310713 0
University of Otago Human Ethics Committee (Health)
Ethics committee address [1] 310713 0
1st Floor, Scott/Shand House, 90 St David's Street, Dunedin, 9016, New Zealand
Ethics committee country [1] 310713 0
New Zealand
Date submitted for ethics approval [1] 310713 0
14/02/2022
Approval date [1] 310713 0
09/03/2022
Ethics approval number [1] 310713 0
H22/030

Summary
Brief summary
Clear orthodontic retainers are frequently worn by patients after orthodontic treatment to prevent dental relapse and provide retention, which means to hold the teeth straight and not letting them move back to where they were. This procedure involves wearing retainers formed by clear sheets of polymerised plastic overnight after the braces are removed to provide the retention of teeth alignment.
Teeth whitening is very commonly considered after patients have their braces removed to improve the aesthetic outcome. The gold standard of at-home whitening is to custom make whitening tray for patients using polymerised plastic with or without reservoir. Due to the similarities of wearing protocol, some practitioners instruct their patient to use the clear orthodontic retainers as whitening tray and carry the whitening material. However, the effect of whitening material on the biomechanical properties on the tray is unknown. The proposed research aims to address current deficits in our knowledge by investigating the biomechanical change in the clear orthodontic retainers when they are used as whitening trays. The change of tooth position and tooth colour will also be observed.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 118610 0
Miss Carrol (Chenyi) Jin
Address 118610 0
Faculty of Dentistry, University of Otago, 310 Great King Street, North Dunedin, Dunedin, 9016
Country 118610 0
New Zealand
Phone 118610 0
+64 3 4797840
Fax 118610 0
Email 118610 0
carroljin@gmail.com
Contact person for public queries
Name 118611 0
Miss Carrol (Chenyi) Jin
Address 118611 0
Faculty of Dentistry, University of Otago, 310 Great King Street, North Dunedin, Dunedin, 9016
Country 118611 0
New Zealand
Phone 118611 0
+64 3 4797840
Fax 118611 0
Email 118611 0
carroljin@gmail.com
Contact person for scientific queries
Name 118612 0
Miss Carrol (Chenyi) Jin
Address 118612 0
Faculty of Dentistry, University of Otago, 310 Great King Street, North Dunedin, Dunedin, 9016
Country 118612 0
New Zealand
Phone 118612 0
+64 3 4797840
Fax 118612 0
Email 118612 0
carroljin@gmail.com

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
The individual data will not be identified as described in the research protocol


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.