Ehab Ahmed Farghaly, Ahmed Hassanien, Zahrah Eldawakhly And Tamer Mounir Nassef,

ABSTRACT
This Study Evaluates The Effect Of Connector Design, (radii Of Gingival Embrasure Angel 0.5 And 1 Mm), And The Veneering Techniques, (Press- On And CAD-On), On The Biomechanics Of Implant Supported Three Units Posterior All Ceramic FPD. A 3-dimentional Finite Element Models Were Constructed Representing Two Implants Together With Implant Abutments Which Were Positioned In Place Of Missing Lower Second Premolar And Second Molar In A An Epoxy Resin Full Arch Model. A Three Unit FPD Virtually Constructed Using IPS E.max ZirCAD Blocks, With A Framework 0.5 Mm Radii Of Curvature At The Gingival Embrasure Of The Connector And Another Framework With 1 Mm Radii Of Curvature At The Gingival Embrasure Of The Connector With The Two Veneering Techniques: Press-on And Cad-on Which Were Virtually Placed Over The Implant Fixtures. Load Was Virtually Applied At The Gingival Fossa Of The Pontic Similarly To The Mechanical Testing And Stresses Were Analyzed. For The Cad- On Group It Was Found That 0.5 Mm Connector Recorded Higher Von Misses Stresses Mean Value (26.37 MPa) Than 1 Mm Connector Mean Value (21.25 MPa). For The Press- On Group The 1 Mm Connector Recorded Lower Von Misses Stresses Mean Value (22.84 MPa) Than 0.5 Connector Mean Value (27.25 MPa). With 0.5 Mm Connector Curvature Design; It Was Found That CAD On Group Recorded Lower Von Misses Stresses Mean Value (26.37MPa) Than Press On Group Mean Value (27.25 MPa). And With 1 Mm Connector Curvature Design; It Was Found That Press On Group Recorded Higher Von Misses Stresses Mean Value (22.84 MPa) Than CAD On Group Mean Value (21.25 MPa). It Was Concluded That The Design Of 1 Mm Gingival Connector Curvature Radii Showed Higher Load To Failure When Compared To The 0.5mm Gingival Connector Curvature Radii Design, And CAD-on Veneering Technique Has Higher Mean Fatigue Failure Than The Press-on Veneering Technique.