[Zinc and caries]

Zinc levels in dentin, enamel, tooth deposit, and mixed saliva in caries were under study. The enamel and dentin Zn levels were measured by means of neutron activation analysis in 244 permanent intact teeth and in 92 permanent carious teeth from subjects died after acute injury. Tooth deposit and mixed saliva Zn levels were measured by the atomic absorption technique in 10 patients with caries and in 10 normal subjects; the groups were matched for dietary habits. The menu of these subjects over a month was examined and the content of daily dietary zinc was determined, and the level of salivary Zn excretion as against Zn content in the food was calculated. The dentin and enamel Zn levels were found increased in caries. A tendency to an increase of Zn level in the saliva was detected; a large proportion of this dietary element was excreted with the saliva in caries patients. The authors suggest that remineralization effect can be achieved in the initial stages of caries by oral and local application of Zn preparations.