A medical study on army recruits has shown tooth decay is on the decline.

Thanks to fluoridated toothpaste and table salt, dentists are finding fewer cavities in their patients’ mouths.

The study was conducted in 2006 on 606 recruits in Thun, the Swiss Dental Association said on Tuesday.

Since 1996 there has been a drop of 37 per cent in caries. In 2006, 27.9 per cent of soldiers were exempt from caries, whereas ten years earlier the number was 15.6 per cent.

Researchers also said smokers had more tooth decay than their non-smoking colleagues.

The causes of the drop cannot be proven scientifically, the Swiss Dental Association said. This could be due to the adding of fluorine in table salt in 1983 and a greater number of dental sealants.

However, neither when or how you brush your teeth seems to play a particular role.