The aesthetics of all-ceramic veneered and monolithic CAD/CAM crowns

The aim of this study was to examine whether crowns fabricated from machinable blocks would achieve acceptable aesthetics and whether these could compete with the aesthetics of restorations obtained by individual layering technique. Fourteen patients, who were to receive single anterior crown restorations, participated in this study. For each person two kinds of crowns were provided: one crown was made with the Cergogold system. The second one was produced in a Cerec machine and was additionally stained. Three independent examiners assessed the aesthetic appearance of crowns fabricated to match each subject's anterior shade. A scale of 1-6 was used to assess the aesthetic adaptation of each crown, with 1 representing excellent characteristics and 3.5 marking the threshold for clinical acceptability. The examiners' scores were averaged, and the mean values were analysed with the Wilcoxon signed rank test (P <= 0.05). Regardless of the fabrication method the crowns were aesthetically acceptable in all 14 patients. The mean values for the layering technique and for the machined restorations did not differ significantly. Within the limits of this study it was documented, that machinable blocks could attain aesthetically satisfying results.