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Physical Models

Each level of evaluation for a case (set of records) requires an accurate representation of the dentition, immediate supporting structures and occlusal relationships. Physical Models should be obtained from impressions that extend far enough into the sulcus to allow accurate reproduction of all soft tissue anatomy.

Presentation of Physical Models

  • Plaster/Stone Casts must be a direct  reproduction of the occlusal result, trimmed to ABO specifications, and/or mounted on an articulator in centric relation. Stereolithic Casts (3D printed stereolithic reproduction of the occlusal result) that meets the 3D Printing Requirements are accepted by the ABO and may be used as substitutes for plaster/stone cases physical casts.   Digital Models are no longer accepted by the ABO.
  • Physical Models should be trimmed in maximum intercuspation or in the intercuspal position. Documentation of a significant difference between the intercuspal and centric relation should be provided; a dimensionally stable bite registration is preferred. Second molars should be fully erupted and in their final position on the post-treatment casts.
  • Physical Models on an adjustable articulator may be presented. Sufficient articulators must be provided to allow ease of examiner observation, with a minimum of one articulator per case.

Model Alterations

Trimming or carving on the anatomical portion of the dental casts should be limited to the removal of bubbles and defects. Alteration of tooth anatomy is considered records falsification. A fixed retainer may be in place when posttreatment casts are made. After the casts are prepared, casts should be soaped (smoothed and polished) in such a manner that tooth and soft tissue detail is not destroyed.

Identification of Models

  • Each dental cast (maxillary and mandibular) must be individually identified with the appropriate labeling.
  • ABO trimmed casts are identified on the "base" as described in Record Identification of Hard Copy Records.
  • Articulated casts are identified with labels placed either on an individual articulator for a set of casts or on the posterior surface of the mounting stone of each cast.