Rehardening Properties of Mucin- or CMC-Containing Saliva Substitutes on Softened Human Enamel

The rehardening of artificially softened human enamel by nine different saliva substitutes and four control solutions in vitro has been investigated by microhardness measurements. The saliva substitutes were all based on the same formula, containing mucins or carboxymethylcellulose (CMC) as the main macromolecules, and phosphate, calcium and fluoride as the main electrolytes, and sorbitol or xylitol. All the saliva substitutes had a rehardening potential. The largest reduction of the rehardening potential was observed after addition of high concentrations of CMC or mucins and the addition of sorbitol. The best rehardening properties were observed for low viscous mucin- or CMC-containing saliva substitutes with xylitol.