Condition category
Oral Health
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Tooth decay is a growing problem in children. The amount of children suffering from cavities (where an area of the tooth decays causing a hole) and requiring dental treatment (fillings) has risen dramatically in recent years. Many children have high amounts of sugar in their diets. The bacteria which are naturally present in the mouth use these sugars to produce acids, which damage the protective enamel on teeth over time, causing cavities. Cavities are most common in molars (back teeth) as they can be more difficult to keep clean when brushing teeth. Fluoride is a natural mineral in the diet, which helps to strengthen tooth enamel, protecting against tooth decay. Research has shown that applying fluoride varnish to teeth can help to stop and prevent tooth decay which leads to the development of cavities. The aim of this study is to find out whether fluoride varnish can help to prevent tooth decay in children.

Who can participate?
Children aged 7-8 who attend state schools in Northwest England (UK)

What does the study involve?
The included schools are randomly allocated into two groups. Children who attend schools in the first group have a fluoride varnish applied to their first permanent molars (back teeth), up to nine times over a three year period. Children who attend schools in the second group do not receive any additional treatment, and continue with their normal tooth care routines. Over the course of the study, the amount of children who need to have fillings is recorded in both groups.

What are the possible benefits and risks of participating?
Participants who receive the fluoride varnish treatment may develop fewer cavities as their teeth have a greater amount of protection than brushing alone. There no notable risks of taking part in the study, although the application of the fluoride varnish may be an inconvenience to some children.

Where is the study run from?
95 Local Authority primary schools in Northwest England (UK)

When is the study starting and how long is it expected to run for?
February 2006 to April 2009

Who is funding the study?
Department of Health (UK)

Who is the main contact?
Professor Keith Milsom

Trial website

Contact information



Primary contact

Prof Keith Milsom


Contact details

Victoria House
United Kingdom
+44 (0)192 859 3733

Additional identifiers

EudraCT number number

Protocol/serial number

PHI/03/C1/017 UK Clinical Research Network portfolio number: 4292

Study information

Scientific title

A cluster randomised controlled trial to measure the benefit of fluoride varnish preventing dental decay when applied to permanent teeth of children for 3 years in the school setting


Study hypothesis

There is a difference in dental decay experience in posterior permanent teeth of children aged 9-11 years at outcome who have received up to nine applications of fluoride varnish when compared with children receiving no fluoride varnish.

Ethics approval

Cumbria & Lancashire REC B approved on 13th December 2005, ethics ref: 05/Q1309/2

Study design

Cluster randomised two compartment parallel trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Dental caries in children


The application of fluoride varnish on the occlusal surfaces of the first permanent molars up to nine times over a three year period.

The control group had no intervention.

Intervention type



Not Applicable

Drug names

Fluoride varnish

Primary outcome measure

The decayed, filled surfaces increment in first permanent molars on the intention-to-treat (ITT) population. The increment will be measured visually.

Secondary outcome measures

1. The decayed, filled surfaces increment in deciduous molars on the ITT population. The increment will be measured visually.
2. A sub group analysis for the frequency of applications of the varnish

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Schools - all state maintained Local Authority primary schools in the study area. Participating schools must have formally agreed to take part int he study.
2. Children - Aged 7-8 years inclusive of children who attend Local Authority primary schools. Participants must have an informed consent form signed by a parent or legal guardian permitting participation of their child.

Participant type


Age group




Target number of participants

80 schools, 2080 children

Participant exclusion criteria

1. Presence of fixed orthodontic appliances involving more than four permanent teeth
2. Participation in any other clinical study during the three months preceding the initial examination
3. Subjects with a history of asthma that required hospitalisation
4. Subjects with a histroy of severe allergic reactions that required hospitalisation
5. Subjects experiencing ulcerative gingivitis or stomatitis
6. Subjects with a history of allergy to any of the ingredients in the test products
7. Subject is uncooperative/ unable to be examined
8. Children attending special schools

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Victoria House
United Kingdom

Sponsor information


University of Manchester (UK)

Sponsor details

Oxford Road
M13 9PL
United Kingdom
+44 161 275 6782

Sponsor type




Funder type


Funder name

Department of Health (UK) - National Co-ordinating Centre for Research Capacity Development, Public Health Initiative (PHI/03/C1/017)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2011 results in

Publication citations

  1. Results

    Milsom KM, Blinkhorn AS, Walsh T, Worthington HV, Kearney-Mitchell P, Whitehead H, Tickle M, A cluster-randomized controlled trial: fluoride varnish in school children., J. Dent. Res., 2011, 90, 11, 1306-1311, doi: 10.1177/0022034511422063.

Additional files

Editorial Notes