Dissolution studies of human enamel treated with aluminum solutions

Dissolution tests using human enamel were conducted after treatment with aqueous solutions of various aluminum (Al) salts. All Al compounds, except those which formed stable Al-complexes, greatly decreased enamel dissolution in a pH 4 acetate buffer. A comparison with fluoride compounds demonstrated that Al was equivalent to SnF2 and more effective than NaF and Na2PO3F. Furthermore, the reduction in enamel dissolution produced by Al persisted after more than three hr of successive demineralization, which was twice as long as that observed with a pH 4.5 SnF2 solution.