[Root canal screws in amalgam restoration of devitalized teeth].

The placing of amalgam screws into root canals is indicated (1) on damaged teeth if the coronal retenion is insufficient, (2) on vital teeth, after canal treatment, as an alternative to dentine anchors like small crews or pins, and (3) for building up crown cores. Four systems of canal screws are described, Dentatus, FKG, Anthogyr and Mooser. The large differences of dimensions and conicity necessitate a better knowledge of the necessary dimensions of the root reamers and drills.