Accuracy of CAD-CAM produced copings

Materials and Methods: A master metal die prepared for an ordinary all-ceramic restoration was the pattern to create 40 identical epoxy-working dies. Under manufacturer's conditions 40 (20 Cicero and 20 Procera) copings were produced at their manufacture center. The three-dimensional images of the preparations were obtained by scanning the master die. To evaluate the scanning quality, 10 copings for each system were produced on the base of one scan, while for the evaluation of the production quality, 10 copings for each system were produced by scanning their epoxy-working dies one by one. The copings were cemented (Panavia F) on their respective epoxy-working die and after that sectioned in three horizontal planes creating three different slices at top, middle and bottom. The slices were analyzed under scanning electron microscopy. The cement space and the coping thickness were measured at Mesial, Distal, Buccal and Lingual in each slice.

Results: Cicero and Procera systems could produce copings with the pre-established coping thickness. The Cicero system could produce cement spaces as pre-established within acceptable borders, while the Procera system creates significantly thicker cement spaces. The scanning procedure was of influence for the Cicero system.

Conclusions: With in the limitations of this study it was concluded that the Cicero system was better be able to reproduce the pre-established design parameters than the Procera system.