Ashraf Mohamed Desokey, Ahmed Gamal Ahmed And Emad Mohamed Tolba Agamy,

ABSTRACT
Objective: The Aim Of This In Vitro Study Is To Evaluate Strain Induced By Different Prosthetic Options Using Single Posterior Implant With Two Splinted Natural Abutments In Lower Unilateral Distal Extension Base Removable Partial Denture (Kennedy Class II).

Materials and Methods: In This Study An Epoxy Resin Model Was Used To Simulate A Class II Kennedy Edentulous Situation With Missing All Molars. The First And Second Premolars Were Splinted As The Main Abutments And An Implant Was Placed At The Site Of The Second Molar As The Distal One. Three Different Prosthetic Designs Were Constructed As Follows: -Group I: (cross Arch Stabilization Partial Overdenture). _ Group II: (side Plate Partial Overdenture). _ Group III: (fixed Partial Denture ( Load Application A Unilateral Ascending Load (25, 50, 75,100 N) Was Frequently Applied To The Selected Points Of The Abutments Over An Epoxy Resin Bite Block With The Loading Tip Of The Device In Axial And Non-axial Directions. Strain Gauges Were Cemented At The Following Areas (buccal And Lingual) To The Abutments And The Implant. (1) The Strain Meter Measure The Strain Every 25 N And Record It In Computer. (2) Five Minutes Were Left Between Each Loading As Period Of Rest To Allow For Heat Dissipation. (3) Every Load Was Applied 5 Times For Each Design And For Each Load Increment.

Results: The Total Stresses Recorded On Both The Implant And The Abutment Teeth In The Three Groups Showed That The Fixed Design Produced The Least Stresses Followed By Cross Arch Design And Maximum Stresses Were Rec Orded In Side Plate Design. The Maximum Micro Strain Range Recorded Under Axial Loading Was 283.662 Micro Strain Units, While Under Oblique Loading It Was 591.07 Micro Strain Units. No Failure Occurred In Any Part Of The Model. All Maximum Stresses Were Just A Fraction Of The Functional Loading Within The Biological Range (1). Conclusion And Clinical Significance: Within The Limitation Of The Current Study It May Be Conducted That The Use Of The Fixed Tooth- Implant Supported Partial Dentures Produced The Least Strain Among The Tested Designs, So It May Be Recommended In These Cases.