After root canal treatment, a tooth may turn gray-brown due to incomplete cleaning of the pulp tissue or staining of the dentin by the medications used. To correct this discoloration in the front of the tooth, instead of placing a crown on the outside of the tooth, “internal bleaching” is applied. In this procedure, the old filling at the back of the tooth is opened, 1-2 mm of space is removed from the top of the root canal filling, and a protective glass ionomer barrier is placed to prevent leakage into the root canal. A whitening gel consisting of a mixture of sodium perborate and hydrogen peroxide is placed inside this opened pulp chamber, and the tooth is temporarily sealed. The gel remains in the tooth for 3-5 days, oxidizing and lightening the color pigments in the dentin tubules from the inside. Once the desired natural tooth color is achieved, the gel is removed, and the tooth is sealed with a permanent aesthetic filling.
