Shimaa Mohamed El Tantawy, Mohamed Sediek. M. Kamel And Waleed. M. Elshahawy,

ABSTRACT
Background: Angulated Abutments In Implant Dentistry Has Become Necessary To Enable The Production Of Functional And Esthetic Restorations As A Result Of Patient And Clinician Expectations.

Purpose: To Evaluate Fracture Resistance Of Three-unit Implant-supported Fixed Dental Prosthesis Fabricated Over Two Abutments With Two Different Angulations (one Was Straight While The Other Was Angled Abutment 15o).

Materials and Methods: Thirty Implant Analogs With Their Abutments (TUT Dental Implant System, Egypt) Were Impeded In Auto-polymerized Acrylic Resin Blocks. Three Unit Porcelain Fused To Metal Restoration Was Fabricated On Each Specimen. Specimens Were Divided According To Abutment Angulation Into Three Groups (n=10 For Each Group). In Group (A), The Two Implant Abutments Are Zero Degree Angulation. Group (B), The Anterior Abutment Is Straight And The Posterior One Is Angled 15o. Group (C), The Two Abutments Have 15o Angulation. The Restorations Were Luted Using Provisional Resin Cement ( Provilat, Promedica , Neumunster , Germany) Under Static Load Of 3 Kg. Specimens Were Tested For Fracture Resistance Using A Universal Testing Machine At A Crosshead Speed Of 1 Mm/min. Fracture Resistance Was Recorded In Newton. The Specimens Were Examined Under Stereomicroscope To Detect The Mode Of Failure. Statistical Analysis Of The Results And Comparison Between Groups Were Performed Using One Way ANOVA (significance At P�0.05) Followed By Post-hoc Test. Result : The Highest Mean Values Were Recorded In The Second Group (B) Which Have Abutments With Different Angulations (2466.79 � 286.11) N Followed By The Third Group Where The Two Abutments Were Angled 15o (2016.21 � 414.44) N, While The Control Group Was The Lowest One (1749.47 � 257.76) N. Conclusion: Statistically Significant Difference (P <0.05) Was Found Between Different Studied Groups. Group (B) Have The Highest Fracture Resistance Value Among The Other Tested Groups .