The aim of this proposed study is to investigate the cost-effectiveness of four methods in preventing fissure caries in permanent teeth, which is the most prevalent dental disease in primary school children in China.

The four caries prevention methods are: resin fissure sealant, atraumatic restorative treatment (ART) sealant, sodium fluoride varnish, and silver diamine fluoride (SDF) solution.

The specific study objectives are:

1. to describe longitudinally the clinical outcomes of using the above four methods to prevent dental caries in the pits and fissures of permanent first molars in school children,
2. to describe the cost of using the above four methods to prevent dental caries in an outreaching dental care programme in China, and
3. to compare the cost-effectiveness of the above four caries prevention methods.

Inclusion Criteria:

• school children in good general health
• has at least one pair of sound permanent first molars with deep occlusal fissures or fissures with signs of early caries

Exclusion Criteria:

• children with major systemic disease or on long-term medication
• children not cooperative and refuse dental treatments