Clinical Contrastive Analysis on the Marginal Fit of the Planting Crowns and Bridges of Metal Porcelain and Zirconium Dioxide All Porcelain

  • Yuhong Wu
Keywords: Metal Porcelain, Zirconium Dioxide, Planting Crown, Marginal Fit


To assess the marginal fit of the planting crowns and bridges of metal porcelain (MP) and zirconium dioxide all
porcelain. 45 complete human maxillary premolars were prepared for the single crown (SC) with the standard
preparation method. The zirconium dioxide all porcelain crown and MP crown were made by CAD-CAM or
hot-pressing process (CAD-CAM zirconia and CAD-CAM MP) and stuck to the teeth with the general resin
adhesive. The nondestructive micro-CT was used to obtain the coronary and sagittal margin and internal gap.
Then, the precision of the fit was calculated with the special software and the statistical analysis on results was
conducted. The accuracy of hot pressed MP crown at the prosthetic margin was significantly lower (p <0.05),
while the performance on the occlusal surface was better (p <0.05). The difference between CAD-CAM
zirconium dioxide all porcelain crown and MP crown was not significant (p> 0.05); However, the performance
of the margin fitting of CAD-CAM zirconium dioxide all porcelain roof was the best. A small quantity of
gelatinizing agent was found at the finishing line, while it was thicker at the occlusal level. Within the scope of
the current in vitro study, the recorded marginal gap was within the acceptable range in clinic, but it was not
related to restorative materials and manufacturing process. Compared with the hot-processing process, the
marginal gap generated by CAD-CAM processing technology used for zirconium dioxide all porcelain and MP
was more insistent; and the tested general resin adhesive can be used together with the two kinds of restorative