This document discusses calcific metamorphosis (CM), which is hard tissue deposition within the root canal space after traumatic dental injuries. CM is commonly seen in anterior teeth and can partially or fully obliterate the root canal space on radiographs. The document covers the definition, causes, incidence, radiographic appearance, histology, and proposed mechanisms of hard tissue formation in CM. It also discusses the controversy around treating teeth with CM, with most literature recommending observation unless symptoms appear. The document provides tips for locating and negotiating canals when CM is present, including using anatomical knowledge and correlating radiographs with tooth morphology.