Abstract: The invention relates to a preparation for use in chemical-mechanical treatment of caries in the form of a two-component caries dissolving liquid in which one of the components consists of sodium hypochlorite and the other component of amino acids, preferably three amino-acids with different charge states; one neutral, one with a negative net charge and one with a positive net charge. A viscosity increasing substance in the form of 3% carboxy methyl cellulose, or any other polysaccharide, as well as a coloring agent, 0.04% Erythrosin, which is able to interact with carious tooth substance has been added to the amino acid component. This means that less liquid is spent, the liquid becomes easier to control and handle and the suspended material becomes more visible.