Abstract
Purpose: In the present study, we clinically evaluated and investigated the setting of the mesiodistal width of crowns, which are important for the recovery of proximal contact of all-ceramic crowns prepared using CAD/CAM.
Methods: An all-ceramic crown preparation was performed on the lower first molar of 5 patients, and data on the shapes and positions of the abutment and adjacent teeth were collected from the master cast using the Everest®. and DECSY®. CAD/CAM systems. Crown fabrication involved the automated design of a standardized all-ceramic crown ("standard-type") and the design of an all-ceramic crown with increased mesio-distal width ("enhanced-type"), followed by ceramic block milling, polishing, and glazing. After measuring the mesiodistal width of the all-ceramic crowns, using a 3D CNC measuring system, we performed a trial insertion. Interdental separation was then measured, and a pull-out test was performed. The area of the contact points was also measured.
Results: The mesiodistal width of both the standard-type and enhanced-type crowns was stable. Interdental separation for the standard-type crown was within 50–110 µm, while the enhanced-type crown exhibited greater resistance to pull-out force than the standard-type crown. There was also no observed impact on the contact point area.
Conclusion: The present findings suggest that the mesiodistal widths of all-ceramic crowns automatically designed using CAD/CAM are within the clinically acceptable range.
