Internal resorption represents a peculiar internal dissolution of dentin, which can extend eventually into the enamel and/or cementum by the tooth root. Usually, only a single tooth is involved, and although the cause is not clearly understood, it is often linked to inflammation.
Clinically, internal resorption in the pulp chamber may lead to the Tooth of Mummery with a developing pink hue in the tooth crown. Resorption in the root canal is not clinically visible; however, perforation of the root usually requires that the tooth be extracted.
Radiographic evidence of internal resorption consists of an unusual widening of the pulp chamber or canal (Figure 58). If the canal is involved, it is virtually impossible to distinguish between internal and external resorption.