Mostafa Abd-elrahim Said, Manal Rafie Hassan And Mohammed Tarek ALwakad,

ABSTRACT
Background. The Placement Of Dental Implants Is In Some Cases Restricted By Various Anatomic Limitations Such As An Insufficient Residual Bone Height. Cantilever Extensions In Implant-supported Prosthetic Partial Dentures May Result In Unfavorable Loading On The Abutment Fixtures. Adjunct Support Of The Distal Cantilever Partial Denture By A Short Implant At Distal Extension Area May Reduce The Overloading On The Dental Abutment Implants. Purpose. To Determine Effect Of Additional Supplementary Support Of A Short Implant For A Cantilever Bridge On Stress Distribution Around Implant Supported Fixed Partial Denture Components Material And Methods. An Acrylic Resin Model Was Fabricated To Be Morphologically Identical To The Maxillary Arch Into Which Two Internal Hexagon Standard-sized Implants (3.75 Mm Diameter-13mm Length To Support A Porcelain Fused To Metal ?pfm? Cantilever Bridge Extending From The Upper 1st Premolar To The Upper 2nd Molar, And A Supplementary Short Implant Beneath The Contact Of The 1st And 2nd Molar), To Which Load Was Applied At Two Points( The 1st Molar Representing The Fixed-fixed Bridge, And The 2nd Molar Representing The Cantilever Extension) And Readings Were Collected From The Strain Gauges(SG) Bonded To The Acrylic Model( One Is Bonded Mesial To The Standard Implant Supporting The 1st Premolar?SG0?, Two Other Bonded Mesial And Distal To The Standard Implant Supporting The 2nd Premolar?SG1, And SG2?, And Another Bonded Mesial To The Short Implant Beneath The Contact Of The 1st And 2nd Molars?SG3?, Respectively), To Determine The Effect Of Stress Application On These Points Throw Strain Determination . Results. Strain(N/m2) Readings From Strain Gauges(SG0, SG1, SG2, SG3) Generated By Applying Force On The Cantilever Extension ? With The Strain Decreasing Slightly From The 4mm Short Implant To The 6mm Short Implant? ( Range From 4mm To The 6mm Short Implant; SG0:22-20.6, SG1:72-69.8, SG2:87-83.8, SG3:174-171), Are Higher Than Those Generated By Applying The Same Magnitude And Direction Of Load On The Fixed-fixed Bridge (range From 4mm To The 6mm Short Implant; SG0: 9-7, SG1: 45-40.4, SG2: 62-56.6, SG3: 153-149) To Show Statistical Significance( P Value >0.05), Yet The Length Of The Short Implant Didn`t Show Statistical Significance Regarding Which Can Decrease Strain More Than The Other (p Value <0.05) Conclusion. The Extra-support Of A Short Implant At Distal Extension Area Had A More Favorable Effect On The Cantilever Prosthesis Than Using A Free Non-supported Cantilever Extension