Embodiments provide the capability to determine a digital 3D model of a patient's teeth obtains projection images acquired by scanning a negative impression of the patient's teeth using a computed tomographic imaging apparatus, where the impression includes a radio-opaque transfer element for a dental implant or crown post. One exemplary method reconstructs, from the projection images, an air volume model within the reconstructed volume and bounded by a transition surface defined according to the negative impression. A transfer element volume model of the transfer element is defined, segmented from the air volume model and from the transition surface. A combined digital 3D model of the patient's teeth is formed according to the air volume model and transfer element volume model. At least a portion of the combined digital 3D model of the teeth is displayed.
