Nancy Sayed Abdel Aziz , Hesham Elansary And Lamia Kherialla,

ABSTRACT


Purpose: The Purpose Of This In Vitro Study Was To Evaluate The Marginal Accuracy And Internal Fit Of Zirconia Monolithic Crowns And Compare It To PEEK Monolithic Crowns, Milled By CAD/CAM. Methods: One Master Stainless Steel Die Resembling A Lower Second Molar Was Fabricated And Duplicated Using One-step Dual Viscosity Impression Technique. Twenty-two Auto Polymerizing Epoxy Replica Dies Were Digitized Using Extra-oral Optical Scanner, And Crowns Were Milled From PEEK And Zirconia Blanks. Internal Gap And Marginal Accuracy Measurements Were Recorded Using Silicone Replica Technique And Digital Microscope Respectively.

Results: For Internal Fit Results, It Was Found That Zirconia Group Recorded Statistically Non-significant Higher Internal Gap Mean Value Than PEEK Group As Indicated By Two-way ANOVA Test (P=0.> 0.05). For Marginal Accuracy Results, It Was Found That PEEK Group Recorded Statistically Significant Higher Marginal Gap Mean Value Than Zirconia Group As Indicated By Unpaired T-test (P=0.0206< 0.05). Conclusion: Both Materials Showed Marginal Accuracy And Internal Gap Values Within The Clinically Acceptable Values. However, PEEK Crowns Showed Superior Internal Fit And Inferior Marginal Accuracy To Zirconia Crowns.