Aim: The present study was performed to evaluate the effect of preparation design on the internal and marginal fit of monolithic multilayered super translucent zirconia crowns.
Methodology: Two typodont teeth (mandibular second molar) were prepared to receive full coverage restorations using two designs: Horizontal finish line (chamfer) and vertical (feather edge) preparations. Twenty resin epoxy dies were duplicated, ten from each typodont tooth. Twenty Multi-layered super translucent zirconia (Katana STML, Kuraray Noritake) crowns were constructed with a CAD/CAM system. All the finished crowns were cemented to their corresponding dies then each sample was vertically sectioned bucco-lingually into 2 sections. Marginal, axial and occlusal gaps were measured at eight defined points on each section using stereomicroscope.
Results: The significance level was set at P Conclusion: the mean marginal and internal gaps varied significantly by the preparation designs, showing better marginal adaptability with chamfer group but still both groups were within the clinically acceptable range.
Keywords: All Ceramic-Monolithic Zirconia-Marginal Fit-Internal Fit.