Digital replacement of the distorted dentition acquired by cone beam computed tomography (CBCT): a pilot study

During cone beam computed tomography (CBCT) scanning, intra-oral metallic objects may produce streak artefacts, which impair the occlusal surface of the teeth. This study aimed to determine the accuracy of replacement of the CBCT dentition with a more accurate dentition and to determine the clinical feasibility of the method. Impressions of the teeth of six cadaveric skulls with unrestored dentitions were taken and acrylic base plates constructed incorporating radiopaque registration markers. Each appliance was fitted to the skull and a CBCT performed. Impressions were taken of the dentition with the devices in situ and dental models were produced. These were CBCT-scanned and the images of the skulls and models imported into computer-aided design/computer-aided manufacturing (CAD/CAM) software and aligned on the registration markers. The occlusal surfaces of each dentition were then replaced with the occlusal image of the corresponding model. The absolute mean distance between the registration markers in the skulls and the dental models was 0.09 +/- 0.02 mm, and for the dentition was 0.24 +/- 0.09 mm. When the method was applied to patients, the distance between markers was 0.12 +/- 0.04 mm for the maxilla and 0.16 +/- 0.02 mm for the mandible. It is possible to replace the inaccurate dentition on a CBCT scan using this method and to create a composite skull which is clinically acceptable.