The main ingredient in Dr. Oral Whitening Powder, eggshell apatite, is a naturally occurring apatite made from eggshells. Apatite is the main component of teeth and bones. 97% of the enamel on the surface of teeth is made of apatite. It is a component that has a high affinity with the human body. In order to mix 40% apatite powder, it would be too hard in paste form and would clog the tube. Therefore, powder toothpaste was the best choice. The particles are so fine that they can get into the crevices of the teeth and directly get involved with the stains, resulting in an amazing whitening effect just by brushing. The high content of eggshell apatite adsorbs pigments, stains, and plaque that cause yellow stains with a strong adsorptive power that you have never felt before.