Mostafa Elhussieny Mohammed Ismail And Cherif Adel Mohsen,

ABSTRACT
This Study Was Carried Out To Evaluate And Compare The Vertical Marginal Gap Distance,and Cyclic Loading Of All-ceramic Crowns Vita Suprinity And IPs E.max CAD (CAD/CAM Milling, Cerec MCXL), Using Two Types Of Finish Lines (deep Chamfer And Radial Shoulder). Specially Designed Stainless Steel Dies Were Constructed And A Total Number Of 40 Samples Were Constructed Representing Two Equal Groups (20 Samples), According To The Type Of Materials (VITA Suprinity And IPs E.max CAD ?CAD/CAM Milling Technique Cerec MCXL) The Twenty Samples Were Further Divided Into Two Divisions (10 Each) According To The Type Of The Finish Line Used (deep Chamfer And Radial Shoulder). Each Division Was Then Divided Into Two Classes (5 Each) (one Class Was Constructed As A Crown Coping And Then Veneered, The Second One Was Constructed As A Full Contoured Crowns). Vita Suprinity And IPs E.max CAD Crowns Were Fabricated Following A Standard Procedure And Standard Dimensions As Controlled By The Cerec MCXL Software. As Regard The Vertical Marginal Gap Test, The Results Showed That IPs E.max CAD Crowns Regardless To Finish Line Type And Veneering, Recorded A Higher Vertical Marginal Gap Mean Value (42.59�2.38 �m) Than Obtained With Vita Suprinity Crowns (36.11�1.76�m). Regardless To The Production Techniques And Veneering, Deep Chamfer Finish Line Recorded A Lower Vertical Marginal Gap Mean Value (37.94�2.11�m) Than Obtained With Radial Shoulder Finish Line (40.77�2.33�m). Regardless To Production Techniques And Finish Lines, Full Contoured Crowns Recorded A Lower Vertical Marginal Gap Mean Value (38.34�2.36�m) Than Obtained Veneering (40.36�2.10�m). The Cyclic Loading Test Data Revealed That IPs E.max CAD Crowns Recorded A Higher Fracture Resistance Mean Value (1013�53.84N) Than The Load Cycled Crowns (888.1�104.4N). Vita Suprinity Crowns Recorded A Higher Fracture Resistance Mean Value (803.7�66.45N) Than The Load Cycled Crowns (703.8�34.26N), Regardless To Finish Line Type And Veneering. The Cyclic Loading Test Data Revealed That IPs E.max CAD Crowns Recorded A Higher Fracture Resistance Mean Value (1013�53.84N) Than The Load Cycled Crowns (888.1�104.4N). Vita Suprinity Crowns Recorded A Higher Fracture Resistance Mean Value (803.7�66.45N) Than The Load Cycled Crowns (703.8�34.26N), Regardless To Finish Line Type And Veneering.