Method: Remineralizing solution was prepared by mixing calcium carbonate (Neocare formula, Turku, Finland) or calcium lactate (experimental formula) containing mineral powders (200mg/ml) with water, simulated body fluid (SBF) or sterile saliva. Pure water, SBF and sterile saliva without mineralizing powders were used as control solutions. Pieces of enamel (3x3 mm) were cut out of sound buccal surface of extracted human molars. Enamel surfaces were acid etched with phosphorous acid for 15s and closed into test tubes containing one of the remineralizing solutions. The enamel samples were immersed for five days before analyzed for Vicker’s surface microhardness.
Result: Phosphorous acid etching decreased the microhardness from 244.9 to 183.3 (p<0.01). Immersion in water or SBF supplemented with Neocare formula powder increased the enamel microhardness to the same level with unetched enamel, while solutions containing calciumlactate did not increase the microhardness. Immersion in sterile saliva alone gave close to equal results than immersion in water or SBF.
Conclusion: Neocare formula powder increases enamel surface hardness after acidic challenge. This powder is potential material for a remineralizing lozenge.