03.04.19
US Patent No. 10,172,769 B2 (Jae Hyun Sim, Bong Kyu Choi, Yu Jung Choi, Hyung Kil Choi); Quorum Bio Co., Ltd., Seoul, has patented a method for whitening teeth that entails coating a tooth whitening composition including peroxide onto the teeth and radiating anions to the tooth whitening composition.