Early Childhood Caries (ECC)Phase 2NCT07455604
Preventing Early Childhood Caries With a Silver Diamine Fluoride Gel
A Phase 2 study testing Silver diamine fluoride gel and Sodium Fluoride varnish in people with Early Childhood Caries (ECC), run by The University of Hong Kong at 1 site in China.
Trial summary
The objective is to compare the efficacy of SDF gel with that of NaF varnish in preventing carious lesions in preschool children when applied at half-yearly intervals over a 24-month period. Read more about this study
- Who is it for?
- Ages 3 to 5 yearsHealthy volunteers can take part
- Conditions the study is for
- Early Childhood Caries (ECC)
- What is being tested?
- Silver diamine fluoride gel and Sodium Fluoride varnish
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,500 participants
- Where
- 1 siteChina
- Study dates
- 1 Jan 2026to 31 Dec 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 3 to 5 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- generally healthy, with parental consents
Who cannot join
- uncooperative and difficult to manage, have major systemic diseases such as porphyria, or are on long-term medication such as anti-epileptic drugs.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Randomized Clinical Trial to Prevent Early Childhood Caries With a Silver Diamine Fluoride Gel
The objective is to compare the efficacy of SDF gel with that of NaF varnish in preventing carious lesions in preschool children when applied at half-yearly intervals over a 24-month period.
Read the detailed description
Aim: The World Health Organization (WHO) included SDF in the WHO Model List of Essential Medicines. SDF is typically available as a 38% aqueous solution, which is runny and difficult to apply. A 38% SDF gel has been introduced but it has not been tested clinically. The objective is to compare the efficacy of SDF gel with that of NaF varnish in preventing carious lesions in preschool children when applied at half-yearly intervals over a 24-month period.
Methods / Design: This non-inferiority randomised clinical trial will recruit 1500 3- to 4-year-old children to receive either SDF gel or NaF varnish every 6 months. The primary outcome is SDF gel will be more effective than NaF varnish in preventing ECC when both are applied at half-yearly intervals at the 24-month follow-up. The same examiner will conduct all examinations at the kindergartens over 24 months. The examiner, the children, and the children's parents will be blinded to treatments. The parents will be surveyed on their child's oral health-related behaviours and socioeconomic background to allow adjustment for effect modification.
Discussion: If the result is as anticipated, clinicians can use SDF gel instead of NaF varnish to prevent ECC. As SDF gel is cost-effective, simple, non-invasive, and non-aerosol generating, it can be widely recommended for prevent early childhood caries. This study will help change the standard of preventive care. If SDF gel is adopted in Hong Kong, it could prevent kindergarten children from developing ECC, thus significantly reducing the burden of ECC among children and the related stress on their families.
- Conditions
- Early Childhood Caries (ECC)
- Being tested
- Silver diamine fluoride gel, Sodium Fluoride varnish
- Keywords
- Children, Preschool, Fluoride Varnish, Silver Diamine Fluoride, Caries, Prevention
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Silver diamine fluoride gelDrug
Also called SDF gel
Application of 38% SDF gel every 6 months over 24 months
Sodium Fluoride varnishDrug
Also called NaF varnish
Application of 5% NaF varnish every 6 months over 24 months
| Study group | Role | What they receive |
|---|---|---|
| Silver diamine fluoride gel | Experimental | 38% silver diamine fluoride gel Receives: Drug: Silver diamine fluoride gel |
| Sodium Fluoride varnish | Active comparator | 5% Sodium Fluoride varnish Receives: Drug: Sodium Fluoride varnish |
What is being measured
The primary outcome is the main question the study is designed to answer.
Caries prevention
The number of sound tooth surfaces that become cavitated caries per child
Measured: The follow-up oral examinations will be conducted every 6 months for 24 months totally
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start1 Jan 2026
- Primary completion31 Aug 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Early Childhood Caries (ECC)Studies of the same condition, open and under way.
- More trials run by The University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 1,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Chun Hung Chu, The University of Hong Kong
- Investigators
- Chun Hung Chu, Principal investigator, The University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07455604
- Sponsor's protocol ID
- UW 24-828
- Status last verified
- Mar 2026
- First submitted
- 3 Mar 2026
- Last updated
- 6 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Clinical Trial to Prevent Early Childhood Caries With a Silver Diamine Fluoride Gel
- ClinicalTrials.gov ID
- NCT07455604
- Acronym / sponsor ID
- UW 24-828
- Conditions
- Early Childhood Caries (ECC)
- Keywords
- Children, Preschool, Fluoride Varnish, Silver Diamine Fluoride, Caries, Prevention
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 1,500 participants (estimated)
- Lead sponsor
- The University of Hong KongUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 31 Aug 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 6 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The objective is to compare the efficacy of SDF gel with that of NaF varnish in preventing carious lesions in preschool children when applied at half-yearly intervals over a 24-month period.
Detailed description
Aim: The World Health Organization (WHO) included SDF in the WHO Model List of Essential Medicines. SDF is typically available as a 38% aqueous solution, which is runny and difficult to apply. A 38% SDF gel has been introduced but it has not been tested clinically. The objective is to compare the efficacy of SDF gel with that of NaF varnish in preventing carious lesions in preschool children when applied at half-yearly intervals over a 24-month period.
Methods / Design: This non-inferiority randomised clinical trial will recruit 1500 3- to 4-year-old children to receive either SDF gel or NaF varnish every 6 months. The primary outcome is SDF gel will be more effective than NaF varnish in preventing ECC when both are applied at half-yearly intervals at the 24-month follow-up. The same examiner will conduct all examinations at the kindergartens over 24 months. The examiner, the children, and the children's parents will be blinded to treatments. The parents will be surveyed on their child's oral health-related behaviours and socioeconomic background to allow adjustment for effect modification.
Discussion: If the result is as anticipated, clinicians can use SDF gel instead of NaF varnish to prevent ECC. As SDF gel is cost-effective, simple, non-invasive, and non-aerosol generating, it can be widely recommended for prevent early childhood caries. This study will help change the standard of preventive care. If SDF gel is adopted in Hong Kong, it could prevent kindergarten children from developing ECC, thus significantly reducing the burden of ECC among children and the related stress on their families.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Silver diamine fluoride gel | Experimental | Drug: Silver diamine fluoride gel38% silver diamine fluoride gel |
| Sodium Fluoride varnish | Active comparator | Drug: Sodium Fluoride varnish5% Sodium Fluoride varnish |
Who may qualify
- Ages
- 3 to 5 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (1 listed)
- generally healthy, with parental consents
Key exclusion criteria (1 listed)
- uncooperative and difficult to manage, have major systemic diseases such as porphyria, or are on long-term medication such as anti-epileptic drugs.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Silver diamine fluoride gelAlso: SDF gelApplication of 38% SDF gel every 6 months over 24 months | Drug | Silver diamine fluoride gel |
| Sodium Fluoride varnishAlso: NaF varnishApplication of 5% NaF varnish every 6 months over 24 months | Drug | Sodium Fluoride varnish |
Primary outcome
Caries prevention
Time frame: The follow-up oral examinations will be conducted every 6 months for 24 months totally
The number of sound tooth surfaces that become cavitated caries per child
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Chun Hung Chu principal investigator
The University of Hong Kong
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Silver diamine fluoride gel and Sodium Fluoride varnish in people with Early Childhood Caries (ECC), run by The University of Hong Kong at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 6 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Caries prevention (time frame: The follow-up oral examinations will be conducted every 6 months for 24 months totally). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Mar 2026.