Project name
Seal or Varnish

£1,380,073 (additional £249K to extend study to 2016 = £1,628,970)

Health Technology Agency

Principal Investigator
Prof Ivor Chestnutt

Seal or varnish logo

Professor Barbara Chadwick  (Clinical and Applied Public Health Dentistry, CU)
Professor Kerry Hood  (South East Wales Trials Unit)
Dr Rebecca Playle (Clinical and Applied Public Health Dentistry, CU)
Professor Ceri Phillips (Health Economics, Swansea University)
Dr Menna Lloyd (Cardiff and Vale University Health Board)
Mrs Maria Morgan (Clinical and Applied Public Health Dentistry, CU)
Dr Simon Murphy  (Cardiff Institute for Society, Health and Ethics, CU)
Mrs Ceri Hodell (Cardiff and Vale University Health Board)
Professor Lindsey Hunter (Clinical and Applied Public Health Dentistry, CU)
Dr Deborah Fitzimmonds  (Health Economics, Swansea University)
Mrs Jacqueline Nuttall (South East Wales Trials Unit)

Type of study

Lay summary
Dental caries (tooth decay) remains a significant source of morbidity in children, particularly those from deprived backgrounds where levels of decay are three times higher than in better off areas. In the worst affected areas 69% of 12 year olds have decay in their permanent teeth. The majority of this (84%) is located on the biting surface of the first molars which erupt at age six. We know that the application of pit and fissure sealants to the biting surface is effective in preventing tooth decay. This treatment consists of a plastic coating that occludes the rough biting surface which harbour decay-causing bacteria.

The application at six-monthly intervals of fluoride varnish, containing high levels of fluoride is also known to prevent decay. This works by strengthening the tooth enamel making in more decay resistant.

What is not know is which of these two modes of treatment works best and which is the most cost-effective. It is also not know which of these treatments are most acceptable from the perspective of children and their parents. Fissure sealant application requires an involved dental intervention (use of rotary brush, tooth surface preparation to make the sealant stick, use of a sucker to keep the tooth dry). Varnish application simply involves painting the tooth surface.  This study will examine the relative clinical and cost effectiveness of these treatments and investigate their acceptability to children and their parents.

The study will take the form of a randomised trial in which children will receive either fissure sealants on their first permanent molars or fluoride varnish. We will determine the success of the study, by comparing the proportion of children who receive the alternative treatments who are caries-free in their first molar teeth after three years. We will also look at the cost effectiveness and patient acceptability of the treatments. The findings from this study will be applicable across the NHS, particularly in areas of high need with greatest health inequalities.

Start date
April 2011

End date
March 2016