Vertical Marginal gap and internal fit of two types of fully anatomic zirconia crowns constructed by different CAD/CAM system

Abstract

Objective: To evaluate the vertical marginal gap and internal fit of two types of monolithic zirconia crowns fabricated using two different CAD/CAM machines.Materials and methods: A sound human maxillary first premolar was selected to receive all ceramic crown preparation. The prepared premolar was then duplicated to produce twenty epoxy dies divided into two groups. Twenty Standardized monolithic translucent zirconia (10 Prettau, & 10 Incoris TZI crowns) were CAD/CAM fabricated onto the epoxy dies. The vertical marginal gap before cementation was measured using a metallurgic microscope. Then the crowns were cemented onto their corresponding epoxy dies using Panavia F 2.0. Half of the specimens were sectioned bucco-lingualy and the remaining specimens were sectioned mesio-distally. Measurements of the internal fit on the Buccal, lingual, mesial, distal and occlusal were taken using a metallurgic microscope. Results were tabulated and statistically analyzed using Wilcoxon signed rank test.Results: The Prettau crowns showed statistically significantly higher vertical marginal gap (Prettau 96.91 ± 2.78 & Incoris TZI 59.17 ± 6.4 μm) and inferior internal fit than that of Incoris TZI crowns (Prettau 117 ± 3.67 & Incoris TZI 103.2 ± 3.61 μm).Conclusions: The Incoris TZI crowns had better marginal integrity and internal fit than that of Prettau crowns.