Some patients believe that their teeth were previously a good color and have become darker after a root canal. In fact, it is important to correct a misconception that root canal treatment itself does not make the tooth darker. The reason why the tooth turns black is that the patient actually came to the treatment with a dead pulp, and the hemoglobin in the necrotic pulp is denatured, which results in the deposition of red pigment, making the tooth gray and black. There is also a situation where the residual pulp must be removed during root canal treatment, because the hemoglobin in the residual pulp denatures, resulting in red pigmentation, and the tooth will turn black after a long time. Under normal circumstances, if you follow the regular procedure to clean and shape the necrotic pulp, the tooth will not turn black after the root canal treatment. There is another case that some people’s teeth will turn black after a long time because the decayed tooth is not removed. In addition, if the crown of the front tooth becomes black after root canal treatment, we can do intra-pulpal bleaching to gradually restore the tooth to a more normal color.