Mohamed Mostafa Radwan , Omaima Elmahalawi And Gihan Elngar,

ABSTRACT


Purpose: Implant-borne Fixed Partial Dentures (FPDs) Should Fit Passively In Order To Avoid Complications Ranging From Cement Degradation To Loss Of Osseointegration. The Aim Of The Study Was To To Investigate The Effect Of Different Abutment Materials (Titanium & Zirconia) On The Stress Distributions And Fracture Resistance Of Fixed-fixed Implant Supported Restoration Replacing Missing Lower Posterior Teeth Mimicking Different Bone Density (D2 & D3).

Materials and Methods: Two Implants Were Anchored In A Measurement Model Based On A Real-life Patient Situation Simulating D2 & D3 Bone Density, Strain Gauges (SGs) Were Fixed Mesially ,distally, Lingual And Buccaly Adjacent Each Implant .20 FPDs (5 Samples From Each Group): Five FPDs For Titanium Abutment In D2 Bone Density , Five FPDs For Zirconia Abutment In D2 Bone Density, Five FPDs For Titanium Abutment In D3 Bone Density & Five FPDs For Zirconia Abutment In D3 Bone Density), Strain Development Was Recorded. For Statistical Analysis, Multivariate Sample Tests Were Performed With The Level Of Significance Set At P = 0.1. Fracture Resistance Were Recorded For Each FPDs .

Results: The Mean Strain Values For The Four Groups At The Different SG Sites Ranged From 26.0 To 1033.6 ?m/m. When Comparing The Four Groups, Significant Differences In Strain Magnitude Could Be Detected, Whereas The Zirconia Abutment Showed Highest Significant Differences In The Strain Magnitude In Either Different Bone Density.

Conclusions: Abutment Materials And Bone Density Appear To Have An Influence On Strain Development In Implant FPDs. As Implant-supported Fixed Partial Denture Have Proven To Be Successful Over Time, The Question Arises As To Whether An ?absolute? Passive Fit Is A Prerequisite For Successful Implant Restorations.