Cone beam computed tomography (CBCT) being used in a growing number of dental clinics, it would be interesting to use this type of device for the purpose of prosthetic impressions. CBCT uses X-ray beem and penetrate soft tissues giving immediate and accurate access to dental preparation limits. In addition, CBCT acquisition is extra-oral, and achieved in a few seconds (as compared to several minutes for other techniques), which is very significant when treating uncooperative patients like mentally disabled, Parkinson etc..
Objective: This pre-clinical, pilot study was designed to evaluate the use of CBCT to create an impression consistent with the achievement of a fixed prosthesis.
Method: A polyurethane resin model including two prepared natural teeth was moulded, then scanned using a commercially available CBCT device. The CBCT-recorded data were transformed and used to design and mill a prosthetic cap by rapid prototyping (CAD-CAM). Cap adaptation on tooth preparation was controlled with a microscanner by assessing tooth-prosthetis interface thickness.
Result: Tooth-prosthetis interface thickness was homogenous and yielded approximately 200 micrometers. When compared to "gold standard" gap (about 100 micrometers), adaptation of the CBCT issued, CAD-CAM cap, on the prepared tooth was found clinically acceptable.
Conclusion: To our knowledge, this is the first study that demonstrates the possibility of using CBCT effectively for fixed prosthesis impression purpose.