Khouloud Mohamed Zaher, Rana Mahmoud Sherif And Maha Ahmed Taymour,

ABSTRACT
Objective: The Aim Of The Study Was To Assess The Fracture Resistance Of IPS E.max CAD (E) Compared To VITA Suprinity(S) Crowns. Methods: A Stainless Steel Die Was Custom Made To Simulate Mandibular First Molar Preparation, Then It Was Duplicated Into Twenty Epoxy Resin Dies. After Scanning The Stainless-steel Die, The Crowns Were Milled. The Samples Were Randomly Divided In To Two Equal Groups (n=20) According To The Material Type (E And S). After Milling, The Crowns Were Finished, Polished And Glazed Prior To The Crystallization Process. The Crowns Were Then Cemented. All Samples Were Subjected To Fracture Resistance Testing Under A Compressive Load Of 5(KN) And At A Crosshead Speed Of 1 Mm/min. Data Was Collected, Tabulated And Statistically Analyzed. The Failure Mode Was Then Examined Photographically Using A Digital Camera.

Results: The Fracture Resistance Testing For The Samples Of Group (E) And (S) Showed That There Was No Statistical Significant Difference Between The Two Groups Where The Mean Values Were ((1767.88�258.55 N) And (1505.73�91.48 N) Respectively. Both Materials Showed Favorable And Unfavorable Pattern Of Failure. Conclusion: The IPS E.max CAD And VITA SUPRINITY Both Showed High Fracture Resistance Values And Thus Can Be Safely Used In The Posterior Region.