A method of treating a tooth of a user. Initially, a tooth is cut to have an opening of at least 1 to 4 mm in the direction along an occlusal surface of the tooth, or a tooth already cut to have such an opening is located. Following ensuring that the opening is dry, powdered selenite is inserted into the opening. Subsequently, the powdered selenite is covered with a dental composite, thereby sealing the powdered selenite in the tooth.
