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Trial registered on ANZCTR


Registration number
ACTRN12616000007437
Ethics application status
Approved
Date submitted
16/12/2015
Date registered
12/01/2016
Date last updated
4/12/2018
Date data sharing statement initially provided
4/12/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Managing tooth decay of primary teeth in young children
Scientific title
Managing tooth decay of primary teeth in young children using silver diamine fluoride to reduce cost, fear and pain
Secondary ID [1] 288162 0
None known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Dental caries 297071 0
Condition category
Condition code
Oral and Gastrointestinal 297301 297301 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
All treatments will be undertaken by an oral health therapist and applied using a micro brush at the time of entering the study.
There will be three treatment groups (and one control group):
1/ A once-only treatment of 38% silver diamine fluoride,
2/ A once-only treatment of 38% silver diamine fluoride followed by an application of potassium iodide.
3/ A once-only treatment of 38% silver diamine fluoride followed by an application of potassium iodide then covered by a glass ionomer fissure sealant, The sealant is expected to remain permanently in place, but its role is to help the soak deeper into the carious tooth and so it is not of concern if the sealant falls off after a short time period.
All children will also receive three-monthly oral health promotion in twice daily tooth brushing with a fluoride-containing toothpaste.
Intervention code [1] 293471 0
Prevention
Intervention code [2] 293478 0
Treatment: Drugs
Comparator / control treatment
A three-monthly applications of 5% sodium fluoride varnish on all primary teeth. The sodium fluoride is applied by an oral health therapist using a microbrush so that there will be four applications over the one year study period. One at the time of entering the study, and then at three monthly applications. All children will aslo receive three-monthly oral health promotion in twice daily toothbrushing with a fluoride-containing toothpaste.
Control group
Active

Outcomes
Primary outcome [1] 296874 0
The arrest of dental caries. The outcome measure for: - tooth decay arrest will be whether tooth decay has spread either laterally or in depth and will be binary (Y/N), The caries arrest abilities of the control and three treatments will be compared: 1/ Spread of dental caries by using standardised dental examination and recording systems, and intra-oral photographs, both of which will be done prior to the first treatments and after 12 months. 2/ Depth of dental caries invasion will be measured using standardised (using bite-wing holders) small bite-wing X-radiographs taken prior to the first SDF treatments and after 12 months. Radiographs will be assessed for caries at both enamel and dentine level for proximal surfaces and dentine level for occlusal surfaces. Scoring will be done independently from the clinical examination by a single examiner using a standard protocol. 3/ SDI Limited will examine the harvested tooth specimens, after they have been extracted, or if a GA is found not to be now necessary, naturally exfoliated, under an ESEM obtaining fast images to determine the extent of SDF and KI penetration into the primary teeth and confirm the arrest of caries. SDI will also do high resolution images both using a SEM and confocal microscopy for high quality images of some of the teeth treated within the study
Timepoint [1] 296874 0
Twelve months after the time the child's parent/carer under the advice of the treating dental clinician from Oral Health Services Tasmania enters the child onto the Royal Hobart Hospital general anaesthetic wait lists because of multiple teeth with dental caries.
Primary outcome [2] 296936 0
The prevention of dental caries. The outcome measure for: - tooth decay prevention will be whether new tooth decay has occurred or not and will be binary (Y/N), The caries prevention abilities of the control and three treatments will be compared: 1/ Spread of dental caries by using standardised dental examination and recording systems, and intra-oral photographs, both of which will be done prior to the first treatments and after 12 months. 2/ Depth of dental caries invasion will be measured using standardised (using bitewing holders) small bitewing X-radiographs taken prior to the first SDF treatments and after 12 months. Radiographs will be assessed for caries at both enamel and dentine level for proximal surfaces and dentine level for occlusal surfaces. Scoring will be done independently from the clinical examination by a single examiner using a standard protocol.
Timepoint [2] 296936 0
Twelve months after the time the child's parent/carer under the advice of the treating dental clinician from Oral Health Services Tasmania enters the child onto the Royal Hobart Hospital general anaesthetic lists because of multiple teeth with dental caries.
Secondary outcome [1] 319580 0
The comparative cost of the treatments will be in mean Australian dollars and is a continuous variable, All dental clinical procedures are described and defined in the Australian Dental Association’s Australian Schedule of Dental Services and Glossary Tenth Edition (2013) as a series of item numbers. These item numbers are accepted by all health funds and government agencies. Oral Health Services Tasmania uses these item numbers. However, the Schedule of Dental Services and Glossary do not distinguish between the fluoride treatments. To ensure we know which fluoride treatment is given to each of de-identified the children, Oral Health Services Tasmania will establish separate item numbers for each of the four procedures. Using the Dental Services and Glossary item numbers, standard dental care that the child would have received if he/she were amenable for dental care under local anaesthetic will be determined by the examining dentist using the standard protocol. There are two forms of economic evaluation depending on whether the child would have received standard dental care within the private or public dental sectors because the two sectors evaluate the economic costs differently. Public Dental Sector The public dental sector economic evaluation will be a cost effectiveness analysis and will establish from the viewpoint of (a) patients and (b) the public dental service provider whether arresting dental caries in deciduous teeth is better managed by the standard dental care the child would have received if he/she were amenable for dental care under local anaesthetic or any of the alternatives from the four groups in the study. The evaluation will be an incremental analysis comparing the additional costs of one alternative over another and the additional benefits of one alternative over another. Clinical costs will be measured according to Oral Health Services Tasmania’s (OHST’s) clinical costing methodology with all clinical and non-clinical cost sources being appropriately identified to ensure they have been credibly valued. The outcome of dental caries arrested will be sourced from data stored within OHST’s patient information management system. Private Dental Sector The private dental sector economic evaluation will also be a cost effectiveness analysis, but by comparing the private fees for the treatment alternatives. Different private sector dentists charge different fees. This is not a problem, as we are comparing treatment costs between dental procedures, and not between dentists. We will use the Children Dental Benefits Schedule (CDBS) and Department of Veterans Affairs (DVA) Scales of Fees to give standardised fees. The reason why both CDBS and DVA scales are required is that there are some procedures in each set of scales that are not covered by the other. A different costing of the fluoride treatments will occur because of the covering with a glass ionomer fissure sealant in two groups and has an item number and a fee. The costing methods will allow us to calculate the mean cost for the fluoride treatments and the standard treatments that the child would have received if he/she were amenable for dental care under local anaesthetic. These will be compared separately for the public and private dental sectors. Cost effectiveness will be measured by comparing: - the relative costs SDF/KI/GI, SDF/GI, SDF, and the standard treatment option (restorations/extractions) as determined by the calibrated examiners using a standardised protocol (attached). The comparison for the public dental sector will involve the relative time taken and material costs. The comparison for the private dental sector will be determined by using the Children Dental Benefits Schedule (CDBS) and Department of Veterans Affairs (DVA) Scales of Fees. - The calculated reduced expenditure due to children being removed from the GA waiting list as it is determined they no longer require the standard dental treatment of restorations/extractions. - The calculated savings in orthodontic treatment from not having primary teeth extracted early which results in forward (mesial) drift of permanent molars and tooth crowding when permanent premolars erupt.
Timepoint [1] 319580 0
Twelve months after the time the child's parent/carer under the advice of the treating dental clinician from Oral Health Services Tasmania enters the child onto the Royal Hobart Hospital general anaesthetic lists because of multiple teeth with dental caries.
Secondary outcome [2] 319735 0
Acceptability of the fluoride treatments by the children and the treating dental clinicians will be binary (preferred/not preferred to standard dental treatments),
Acceptability to the child and their parent/carer and ease of use will be measured by
- Practicality of use on the children by the use of surveys of parents/carers and the treating dental therapists.
- Compliance of children to treatment (Proportion of children who accept treatment).
Timepoint [2] 319735 0
Twelve months after the time the child's parent/carer under the advice of the treating dental clinician from Oral Health Services Tasmania enters the child onto the Royal Hobart Hospital general anaesthetic lists because of multiple teeth with dental caries.
Secondary outcome [3] 319736 0
Presence while on the general anaesthetic waiting list of toothache, of being uncomfortable about the appearance, any smell, of being afraid, of having bad breathe will be binary (Y/N),
This measure will be found by the use of surveys of parents/carers.
Timepoint [3] 319736 0
Twelve months after the time the child's parent/carer under the advice of the treating dental clinician from Oral Health Services Tasmania enters the child onto the Royal Hobart Hospital general anaesthetic lists because of multiple teeth with dental caries.
Secondary outcome [4] 319737 0
Pre- and post-trial dental plaque and bleeding gums will be measured as indicators of oral hygiene (independent from the parent/carer)and will be binary (Y/N).
These will be determined by the examining dentist using standard protocols.
Timepoint [4] 319737 0
Twelve months after the time the child's parent/carer under the advice of the treating dental clinician from Oral Health Services Tasmania enters the child onto the Royal Hobart Hospital general anaesthetic lists because of multiple teeth with dental caries.

Eligibility
Key inclusion criteria
Inclusion criteria are children aged one to eight years with multiple carious primary teeth and who are being entered on the Oral Health Services Tasmania/Royal Hobart Hospital General Anaesthetic Waiting List.
Minimum age
1 Years
Maximum age
8 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Developmental dental abnormalities such as enamel defects, serious chronic medical conditions, such as congenital heart disease and children with teeth with symptoms or signs that are pulpal in origin

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)
The person who determines if a subject is eligible for inclusion in the trial will be unaware, when this decision was made, to which group the subject would be allocated. Children aged one to eight years on the Oral Health Services Tasmania/Royal Hobart Hospital General Anaesthetic Waiting List will be randomly assigned to one of control or one of three treatment groups based on computer-generated random numbers by a member of the research team, i.e. not the person who determines if a subject is eligible for inclusion in the trial nor the treating clinician.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computer-generated random numbers
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Phase 3
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Currently about 436 children are treated every two years at under general anaesthetic at the Royal Hobart Hospital and the current wait for dental treatment on the general anaesthetic list in southern Tasmania is over 12 months (Oral Health Services Tasmania, 2015) and with the reduced theatre time being allocated for dental procedures, the waiting time is expected to increase. The trial will be will be a rolling one in that new participants will be recruited until there are adequate sample sizes in each treatment group. Hence, a period of two years has been allowed for the complete trial. In 2014, 77% of children treated under general anaesthetic were one to eight years of age (Oral Health Services Tasmania, 2015), indicating that approximately 336 children on the general anaesthetic . We expect to be able to detect the clinical difference between the treatment arms of once-only silver diamine fluoride and three-monthly sodium fluoride varnish treatments to be the same as in a study by Lo et al. (2001). Sample size calculations based on alpha=0.05 and power=0.80 using data indicate 43 per independent group for arrested caries based on the Lo et al. (2001) study that compared the dental caries arrest abilities of silver diamine fluoride with sodium fluoride (Arrested caries surfaces: Difference in means=1.49, standard deviation=2.45, Independent groups n=43 per group). Allowing for a 20% drop out rate means (43x120%x4=) 198 children will be required for the trial.
Survey data and data entered into the Oral Health Services Tasmania TitaniumTM dental computer software will be transferred onto an ExcelTM spreadsheet in a de-identified format and analysed using SAS/SUDAAN. Practicality of use on patients will be obtained by the use of surveys of parents/carers and of Oral Health Services Tasmania clinical staff. Survey data will be entered onto the University of Tasmania computers.
Bivariate analysis will be undertaken to identify and describe associations between the outcome variables (dental caries arrests/prevention, effectiveness) and main explanatory variables (the dental treatments) and to find potential confounders (socio-economic, age, and sex). For the relative dental caries (tooth decay) arrest and prevention abilities on the primary teeth of children of the fluoride treatments, the outcome measures are categorical (Y/N). Variables (e.g. dental hygiene, age, sex, socio-economic status) will be considered a confounder if it is found to be significantly association with both the independent (type of fluoride treatment given) and dependent variables (dental caries arrest and prevention). If more than one confounder is found, multivariate analysis will be undertaken with the silver diamine fluoride treatments and dental caries arrest and prevention as the outcome measure. A multivariate analysis inclusive of each of the four treatment options (SDF, SDF/GI , SDF/KI/GI and standard dental treatment of restorations or extractions) will then be undertaken with dental caries arrests/prevention and treatment effectiveness as dependent variables. We are expecting the cost-effectiveness of the fluoride treatments to be similar, but much lower than standard dental care. The cost-effectiveness in the private and public sectors will be analysed separately.

Analysis of primary and secondary outcomes
An intention to-treat analysis of the results will be conducted based on the initial treatment assignment and not on the treatment eventually received. Demographic data will be analysed using descriptive statistics.

Dental caries arrest and prevention abilities will be analysed using logistic regression to determine the difference between treatments. Adjusted and unadjusted odds ratios from the logistic regression will be reported.
Cost effectiveness will be estimated in Oral Health Services Tasmania by comparing the historical mean time and cost of each standard dental procedure with that of the SDF treatments. A private sector analysis will compare treatments using the Child Dental Benefits/Department of Veterans Affairs scale of fees. The cost-effectiveness outcomes of the fluoride treatments compared to the standard dental care are continuous (dollar value). Categorical variables will be summarised as percentages and corresponding 95% intervals, while ordinal and continuous variables will be summarised as means and 95% confidence intervals.

Poisson analysis will be used to assess the association between interventions and child and clinician acceptability. The prevalence ratio or rate ratio with a 95% CI will be calculated, depending on the outcome considered. If necessary, relevant independent variables will be included for adjustment in the final models.

All variables will be examined for normality and appropriate data transformations will be applied. Potential confounders (socio-economic, age, and sex) and the impact of the interventions will be examined using univariate and multivariate methods.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
TAS
Recruitment hospital [1] 4970 0
Royal Hobart Hospital - Hobart
Recruitment postcode(s) [1] 12462 0
7000 - Hobart

Funding & Sponsors
Funding source category [1] 292567 0
University
Name [1] 292567 0
University of Tasmania
Address [1] 292567 0
Private Bag 103
Hobart
Tasmania, 7001
Country [1] 292567 0
Australia
Primary sponsor type
University
Name
University of Tasmania
Address
Private Bag 103
Hobart,
Tasania, 7001
Country
Australia
Secondary sponsor category [1] 291287 0
Government body
Name [1] 291287 0
Oral Health Services Tasmania
Address [1] 291287 0
2 Archer Street
New Town,
Tasmania, 7008
Country [1] 291287 0
Australia
Secondary sponsor category [2] 291299 0
Commercial sector/Industry
Name [2] 291299 0
SDI Limited
Address [2] 291299 0
3-13 Brunsdon Street
Bayswater Victoria 3153
Country [2] 291299 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294055 0
Human Research Ethics Committee (Tasmania)
Ethics committee address [1] 294055 0
Private Bag 1
Hobart, Tasmania, 7001
Ethics committee country [1] 294055 0
Australia
Date submitted for ethics approval [1] 294055 0
24/07/2015
Approval date [1] 294055 0
07/12/2015
Ethics approval number [1] 294055 0
H0015064

Summary
Brief summary
The primary aim is to determine, over a 12 month period, the relative dental caries (tooth decay) arrest and prevention abilities on the primary teeth of children aged one to eight years of a once-only treatment of 38% silver diamine fluoride, compared to three-monthly applications of 5% sodium fluoride varnish in the Tasmanian clinical situation.

The secondary aims are to compare:
1/ The dental caries prevention and arrest abilities of once-only treatments of silver diamine fluoride, silver diamine fluoride/potassium iodide, and silver diamine fluoride/potassium iodide/glass ionomer fissure sealant .
2/ The effectiveness as measured by relative cost, patient and clinician acceptability of treating tooth decay on the primary teeth of children of silver diamine fluoride, silver diamine fluoride/potassium iodide, silver diamine fluoride/potassium iodide/glass ionomer fissure sealant, and the standard dental treatment of restorations and extractions as determined by calibrated dentists if it were feasible to do the care under local anaesthetic.
Trial website
Trial related presentations / publications
Silver Diamine Fluoride Clinical Trial, ADOHTA Conference 2018, 5th International Conference, 27-29th September 2018, Hobart, Tasmania
Public notes

Contacts
Principal investigator
Name 62234 0
A/Prof Leonard Crocombe
Address 62234 0
Centre for Rural Health
University of Tasmania
Private Bag 103
Hobart, Tasmania, 7001
Country 62234 0
Australia
Phone 62234 0
+61 419 597 756
Fax 62234 0
Email 62234 0
leonard.crocombe@utas.edu.au
Contact person for public queries
Name 62235 0
A/Prof Leonard Crocombe
Address 62235 0
Centre for Rural Health
University of Tasmania
Private Bag 103
Hobart, Tasmania, 7001
Country 62235 0
Australia
Phone 62235 0
+61 419 597 756
Fax 62235 0
Email 62235 0
leonard.crocombe@utas.edu.au
Contact person for scientific queries
Name 62236 0
A/Prof Leonard Crocombe
Address 62236 0
Centre for Rural Health
University of Tasmania
Private Bag 103
Hobart, Tasmania, 7001
Country 62236 0
Australia
Phone 62236 0
+61 419 597 756
Fax 62236 0
Email 62236 0
leonard.crocombe@utas.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Undecided
No/undecided IPD sharing reason/comment
undecided by research team
What supporting documents are/will be available?
No other documents available
Summary results
No Results