According to a recent report by Lady Mellanby and others, 15·5 per cent. of London schoolchildren aged five years were free from dental caries in 1955, compared with 28·1 per cent. in 1947. A report from Staffordshire which was included in the Chief Medical Officer's Annual Report for 1955 also showed a decrease. Research into the reasons and into methods of prevention is proceeding; but my right hon. and learned Friend is advised that the deterioration is due largely to faulty dietetic habits and that the main hope of prevention lies in dental health education reinforced where necessary by the fluoridation of water.