Dalia Attia Ahmed Abdou , Ibrahim Ramadan Eltorky And Saied Muhammed Abdullah,

ABSTRACT
Objective: The Objective Of The Present Study Was To Evaluate The Seating, Retentive Forces And Fatigue Wear Resistance Of Two Attachments (Ball & Socket And Bar & Clip) In A Mandibular Implant Overdenture.

Materials and Methods: Two Groups Were Prepared (A, B); Each Group Contain 5 Specimen, Each Specimen Consisted Of Two Epoxy Resin Blocks Resembling The Mandibular Arch And Overdenture Base. Two Parallel Implant Fixtures 22 Mm Apart Were Embedded In One Of The Blocks With The Male Part Of The Attachments, While In The Other Block The Female Part For Each Attachment System Was Assembled. A Universal Testing Machine Was Used To Measure The Seating And Retentive Forces Of The Attachments Over The Cycles Applied.

Results: The Seating Force Of The Ball & Socket Recorded (16.03055 N) While The Bar & Clip Recorded (2.46741 N) At 10,000 Cycles, Also There Was Gradual Decrease In The Seating Forces Of Both Attachment Systems. The Ball & Socket Attachments Registered The Highest Initial Retention Value (72.53403 N) Followed By The Bar & Clip Attachments (3.940074 N). There Was Gradual Decrease In The Retentive Forces In The Ball & Socket (24.89841 N) And Bar & Clip Attachments (1.267216 N) After 5500 Cycles. Conclusion: The Retentive Properties Of Ball & Socket Attachments Exceeded The Bar & Clip Attachments, The Seating And Retentive Forces Gradually Decreased Over Time For Both The Evaluated Attachment Systems.