Digital implant impressions by cone-beam computerized tomography: a pilot study.

OBJECTIVES: To evaluate the adjustment of structures designed from a digital impression of implants obtained by cone-beam computerized tomography (CBCT).

MATERIALS AND METHODS: Thirty implants were placed in five edentulous mandibles of fresh cadaver heads, six per mandible. Special scan bodies were screwed in the implants and a CBCT was taken. DICOM images were converted to STL and digitally processed to obtain a digital model of the implants. A Cr-Co structure was designed and milled for each mandible, and the adjustment was assessed as in a real clinical situation: passivity while screwing, radiographic fitting, optical fitting, and probing.

RESULTS: Good adjustment was found in three of the structures, and only slight discrepancies were found in the other two.

CONCLUSION: Cone-beam computerized tomography might be a valid impression-taking method in full-mouth rehabilitations with implants. Further evaluations are needed with more implant and CBCT systems. The radiation dose might be considered when deciding to use this impression system. The types of patients appropriate for this treatment option should also be determined to fulfill the principles of the ALARA law.