Three-dimensional evaluation of the machinability of monolithic CAD/CAM-generated posterior crowns by nano-hybrid ceramic / 대한치과재료학회지

ABSTRACT

The purpose of this study comparatively analyzed the machinability of various dental hybrid blocks manufactured by using the CAD/CAM system. Three hybrid composite blocks (Vita enamic, Lava Ultimate, GC Cerasmart) were used for experimental groups and one conventional ceramic block (Vita Mark II) was used for control. The digital impression of the master model and abutment was taken by using a scanner, and then the CAD software program was used to design restorations. The four-axis milling machine (inLab MCXL; Sirona Dental Systems GmbH, Bensheim, Germany) was used four materials. The digitized data was superimposed with 3D inspection software to quantitatively obtain the machinability of a ceramic crown, and visual differences were confirmed with a color map. The root mean square (RMS) values of ceramic crown group were statistically analyzed with one-way ANOVA (α=0.05). While there was a significant difference in the machinability of the internal surface, among four groups, there was statistically significant difference between conventional (VM group) and hybrid ceramic (VE, LU, GC groups) (p<0.05). Consequently, the machinability of VM is lower than that of other hybrid ceramics, and the machinability of VE is better than that of LU and GC. For ceramics as final restorations, manufacturing of dental restorations using hybrid composite ceramic is recommended.