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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Management of dental plaque with air-polishing in patients with orthodontic braces
Scientific title
Management of biofilm formation with Air-Flow in patients with fixed orthodontic appliances
Secondary ID [1] 298522 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Dental plaque 313327 0
Gingivitis 313328 0
Enamel demineralisation 313329 0
Condition category
Condition code
Oral and Gastrointestinal 311767 311767 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Study type
Description of intervention(s) / exposure
Air-polishing with EMS Air-Flow
Two quadrants of the mouth will receive the Air-Flow cleaning during their monthly orthodontic visits. The treatment protocol will be set according to the manufacturer’s recommendations; that is the distance of the air-polishing tip to the surface of the enamel will be between 3 to 5 mm. The angulation of the central beam will be between 30 to 60 degrees. A set cleaning time of five seconds only for each tooth in each quadrant to be treated will be enforced with a stopwatch.

The system used is the Air-Flow Handy 3.0 Plus handpiece (Electro Medical Systems, Nyon, Switzerland). The Powder used is Air-Flow Sub+Supragingival Plus Powder with a particle size of 14µm granules. The device settings will standardised at an air pressure of 5 bar with a water flow rate of 20mL/min. The Air-Flow intervention will be conducted by only one person, the investigator.

The Air-Flow will be conducted by a single dentist of five years experience. The intervention will be monitored by a digital clinic note placed on the patient's file using the patient management software Titanium.

Participants will receive one treatment followed by another (in a random order), but both will be conducted at the start of the same monthly orthodontic adjustment appointment.
Intervention code [1] 314769 0
Treatment: Devices
Comparator / control treatment
Traditional Oral Hygiene Instruction

The other two quadrants of the mouth, as pre-determined by their allocated group, will be cleaned by the patient themselves, following traditional clinic-based oral hygiene instruction of the Modified Bass technique.

A set brushing time will be calculated for each quadrant, at five seconds multiplied by the number of teeth in the quadrant, and will be enforced with a stopwatch. Participants will brush with a provided standardised Colgate soft bristled regular manual toothbrush and Colgate total classic 12 (1000ppm) toothpaste. This will occur during their monthly orthodontic visits. They will also be given the same standardised toothbrush and toothpaste for home use. The amount of toothpaste to be used at all times oral hygiene or home toothbrushing is carried out is measured from the front to back of the bristles.
Control group

Primary outcome [1] 320449 0
Primary outcome 1: Silness and Löe Gingival Index

To assess the clinical severity of gingival inflammation as well as its location for each patient.
Recorded using a blunt periodontal probe.
Four locations around each tooth (buccal, mesial, distal and lingual) are given a score according to the index.
Timepoint [1] 320449 0
Timepoint: Every monthly adjustment appointment (pre intervention) for 6 months
Primary outcome [2] 320450 0
Primary Outcome 2: Modified Silness and Löe Plaque Index

Plaque will be disclosed to allow accurate assessment of accumulation. The modified Silness and Löe index as described by Williams will be used. The tooth will be divided into mesial, distal, gingival, and incisal (occlusal) regions in relation to the bracket.
Plaque is then scored in each area based on four codes used in the original Silness and Löe index and values summed to obtain a total score, which can range between 0 and 16 for each tooth.
Timepoint [2] 320450 0
Timepoint: Monthly adjustment appointments (pre and post intervention) for 6 months
Primary outcome [3] 320451 0
Primary outcome 3: Mean percentage fluorescence loss

Using Inskeptor systems Q-Ray Pen Quantitative Light-induced Fluorescence and Q-Ray software.
To measure changes in enamel mineral content.
Timepoint [3] 320451 0
Timepoint: Baseline, 6 months after intervention
Secondary outcome [1] 371632 0
Secondary outcome 1: Plaque pixel coverage change in R30 (red autofluorescence of bacteria porphyrins)

Using Inskeptor systems Q-Ray Pen Quantitative Light-induced Fluorescence and Q-Ray software.
Timepoint [1] 371632 0
Timepoint: Every monthly adjustment appointment (pre intervention) for 6 months

Key inclusion criteria
• Poor oral hygiene and plaque control (defined by patients currently under treatment who have attended at least two consecutive adjustment appointments where poor oral hygiene has been noted in their clinical record)
• Permanent dentition
• Minimum of 20 natural teeth
• Full upper and lower fixed appliances, with conventional buccal stainless-steel metal brackets (RMO Mini-Taurus, Alexander prescription)
Minimum age
10 Years
Maximum age
30 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
• Systemic disease (e.g. diabetes, hemophilia, salivary dysfunction etc.)
• Patients with respiratory difficulties (e.g. chronic bronchitis, asthma etc.) or suffering from upper respiratory tract infections
• Patients at risk with bacteraemia (e.g. endocarditis, pregnancy, breast feeding, immune deficiency etc)
• Physical or mental impairment that affects ability to self-perform home oral hygiene
• Periodontal disease
• Enamel defects (e.g. fluorosis, enamel hypoplasia etc)
• Current or previous smoker
• Residing in non-fluoridated area
• Taking antibacterial medication (e.g. antibiotic therapy, antibacterial mouth rinses etc)
• Fixed or removable functional orthodontic appliances (e.g. forsus, powerscope etc)

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Opaque, sealed envelopes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using computer-generated random numbers
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Split-mouth study design
Balanced block randomisation (with a block size of four and by blocking on sex)

Participants will be randomly allocated to either Group A or Group B.
Group A will receive the experimental intervention (Air-Flow) to quadrants one and three, and the control intervention (OHI) to quadrants two and four. Whilst, Group B will receive the experimental intervention (Air-Flow) to quadrants two and four, and the control intervention (OHI) to quadrants one and three
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The sample size determination was based on previous estimates of plaque index variability in adolescents requiring orthodontic treatment (111, 112). To detect a decrease in the plaque index greater than or equal to 30% with 80% power, a total of 29 patients are needed. To allow for possible dropout during the study, we aim to recruit 34 patients.

The outcomes will be measured at tooth level, but the randomization will be at participant level, multilevel linear regression will be used for the analysis to control for the clustering of teeth within participants.
Data will firstly be analysed by descriptive statistics and normality tests. An intention-to-treat analysis will be carried out using mixed-models and, where appropriate, nonparametric M.
Gingival and Plaque Indexes are ordinal scale data and will be analysed by non-parametric statistics. A Chi-squared test will be conducted on this data. The QLF data is a ratio scale and therefore will be analysed by parametric statistics. Mann-Whitney U if not normally distributed and ANOVA if normally distributed.
For all statistical analyses, alpha error will be set at 0.05 and P < 0.05 will be considered significant.
The statistical software used will be SPSS 20.

111. Acharya S, Goyal A, Utreja AK, Mohanty U. Effect of three different motivational techniques on oral hygiene and gingival health of patients undergoing multibracketed orthodontics. The Angle orthodontist. 2011;81(5):884-8.
112. Peng Y, Wu R, Qu W, Wu W, Chen J, Fang J, et al. Effect of visual method vs plaque disclosure in enhancing oral hygiene in adolescents and young adults: A single-blind randomized controlled trial. American Journal of Orthodontics and Dentofacial Orthopedics. 2014 2014/03/01/;145(3):280-6.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 21615 0
New Zealand
State/province [1] 21615 0

Funding & Sponsors
Funding source category [1] 303067 0
Name [1] 303067 0
University of Otago, Sir John Walsh Research Institute - Fuller Grant
Address [1] 303067 0
310 Great King St, North Dunedin, Dunedin 9016
Country [1] 303067 0
New Zealand
Funding source category [2] 303068 0
Name [2] 303068 0
New Zealand Dental Association Research Foundation
Address [2] 303068 0
NZDA House, 1/195 Main Highway, Ellerslie, Auckland 1051
Country [2] 303068 0
New Zealand
Primary sponsor type
James Millar
Faculty of Dentistry - University of Otago
310 Great King St, North Dunedin, Dunedin 9016
New Zealand
Secondary sponsor category [1] 303049 0
Name [1] 303049 0
Peter Lei Mei
Address [1] 303049 0
Faculty of Dentistry - University of Otago
310 Great King St, North Dunedin, Dunedin 9016
Country [1] 303049 0
New Zealand
Secondary sponsor category [2] 303050 0
Name [2] 303050 0
Professor Mauro Farella
Address [2] 303050 0
Faculty of Dentistry - University of Otago
310 Great King St, North Dunedin, Dunedin 9016
Country [2] 303050 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 303616 0
University of Otago Human Ethics Committee (Health)
Ethics committee address [1] 303616 0
90 St David Street
North Dunedin
Dunedin 9016
Ethics committee country [1] 303616 0
New Zealand
Date submitted for ethics approval [1] 303616 0
Approval date [1] 303616 0
Ethics approval number [1] 303616 0

Brief summary
Investigate the efficacy of air-polishing in managing dental plaque in patients wearing fixed orthodontic appliances and see if it can reduce dental plaque accumulation and the unwanted outcomes of gum inflammation and early stages of dental decay. Air-polishing is a clinic-based procedure that utilises a pressurised jet of air, water and abrasive powder through a specialised handpiece. We suspect that the procedure will potentially offer an efficient, effective and financially viable technique to improve oral health care for patients undergoing orthodontic treatment with fixed appliances.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 94274 0
Dr James Millar
Address 94274 0
Faculty of Dentistry - University of Otago
310 Great King St, North Dunedin, Dunedin 9016
Country 94274 0
New Zealand
Phone 94274 0
+64 03 479 8889
Fax 94274 0
Email 94274 0
Contact person for public queries
Name 94275 0
Dr James Millar
Address 94275 0
Faculty of Dentistry - University of Otago
310 Great King St, North Dunedin, Dunedin 9016
Country 94275 0
New Zealand
Phone 94275 0
+64 03 479 8889
Fax 94275 0
Email 94275 0
Contact person for scientific queries
Name 94276 0
Dr Peter Lei Mei
Address 94276 0
Faculty of Dentistry - University of Otago
310 Great King St, North Dunedin, Dunedin 9016
Country 94276 0
New Zealand
Phone 94276 0
+64 021 024 39799
Fax 94276 0
Email 94276 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
What data in particular will be shared?
All of the individual participant data collected during the trial
When will data be available (start and end dates)?
Following publication - available for 5 years after
Available to whom?
Case-by-case basis at the discretion of Primary Sponsor
Available for what types of analyses?
Only to achieve the aims in the approved proposal
How or where can data be obtained?
Access subject to approvals by Principal Investigator
What supporting documents are/will be available?
No other documents available
Summary results
No Results