A £1m health study to prevent child tooth decay will focus on some of south Wales' most deprived communities.
Figures show a three-fold rise in tooth decay in children living in areas of deprivation compared with more affluent communities.
So dental health workers will deliver a primary school-based dental prevention programme via mobile dental clinics.
The three-year study will treat 2,800 primary school pupils from within Communities First areas in south Wales.
Experts from Cardiff and Swansea universities and Cardiff and Vale University Health Board's Community Dental Service have been awarded the money by the National Institute for Health Research.
The children will be followed up for three years to investigate the effectiveness of two forms of treatments used to prevent tooth decay.
Professor Chestnutt Ivor Chestnutt, consultant in dental public health from Cardiff University's school of dentistry is leading the study.
He said the two common forms of treatment were using plastic sealants on the biting surface, or painting of fluoride varnish onto the tooth surface.
"Both of these treatments have been around for many years and have been shown to work.
"To know which works best and is most acceptable from the perspective of the children, their parents, the dental staff carrying out the treatments, and the schools in which the treatment will be delivered will be of tremendous value to the National Health Service.