Calcium hydroxide in the treatment of external root resorption.

A case is presented in which calcium hydroxide was used in endodontic treatment of external root resorption in a tooth with a necrotic pulp, during active orthodontic movement. A calcified deposit formed, filling a defect, and the tooth was subsequently obturated with gutta-percha. Thus, both types of therapy--endodontic and orthodontic--were performed simultaneously.