ALTERATIONS IN FORMATION OF RAT DENTINE AND ENAMEL INDUCED BY VARIOUS IONS

A large number of ions have been found to induce alterations in the mineralization of rat incisor dentine and enamel when injected subcutaneously. Hypomineralized layers, and in a few cases hypermineralized layers, were observed in dentine and/or enamel using microradiography. The effect of most of the ions was temporary and normal dentine and enamel were formed after completion of the altered layers. Many ions consistently altered either dentine or enamel predominantly or both tissues to a similar degree. These three classes of ions include: cobalt, stannous, ferrous, stannic, molybdate, borate and bisulphate ions predominantly affecting enamel; mercurous, cadmium, thallous, iridium, nickel, uranium, cupric, zinc, beryllium, bismuth, yttrium, caesium, lead, citrate, phosphate (PO4 and HPO4) and bicarbonate ions predominantly affecting dentine; manganous, antimony, rubidium, barium, strontium, chromic, lithium, magnesium, aluminum, selenate, bifluoride, fluoride, oxalate, iodide, bromide and phosphate (H2PO4) ions disturbing both dentine and enamel similarly. Four major categories of ion activity are discussed: non-specific effects; interference with specific cells, matrices or enzymes; effects on crystal nucleation, growth and structure; other factors, such as changes in serum calcium and phosphate levels. © 1969.