Basma Osama Abbas Ghonim, Dina Magdy El Shehawi And Gihan Abd-El Hady El Naggar,

ABSTRACT


Aim: The Study Was Conducted To Assess The Fracture Resistance Of Zirconia Reinforced Lithium Silicate All Ceramic Material ?Celtra Press? Compared To Lithium Disilicate One ?IPS E-max Press? Under Simulated Oral Conditions.Methodology: Fourteen Ceramic Crowns Were Fabricated On Epoxy Dies Which Were Duplicated From Stainless Steel Master Die And Divided Into Two Equal Groups (n=7) According To The Material Of Construction; Group A: Crowns Fabricated With IPS E-max Press Material And Group B: Crowns Fabricated With Celtra Press Material. The Crowns Were Then Cemented Onto Their Corresponding Dies With A Self-adhesive Resin Cement And Subjected To Thermocycling And Cyclic Loading. Then They Were Loaded To Fractur In A Universal Testing Machine. The Results Were Tabulated And Statistically Analyzed Using Kolmogorov-Smirnov And Shapiro-Wilk Tests. Student T-test Used To Compare Mean Values. The Significancelevel Was Set At P ? 0.05 And 95% Confidenceinterval. Statistical Analysis Was Performed Using Graph Pad Instat (Graph Pad, Inc.) Software For Windows

Results: The Mean ? SD Values Of Fracture Resistance Were Recorded For Lithium Disilicate Group (1706.01 ?154.32 N) Meanwhile The Mean ? SD Value Recorded With Celtra Group Were (1550.67?196.71 N). Conclusion: Zirconia Reinforced Lithium Silicate Ceramic Crowns Produced Comparable Fracture Resistance Values To Lithium Disilicate Ceramic Crowns And Both Tested Materials Are Within The Clinically Acceptable Values In The Posterior Area.