Abstract:

Abstract:Objective
To explore the effect of  aveolar ridge resorption on the stress distribution of abutment and peridontal tissue in attachment denture,and provide evidence for the application of attachment denture in clinic. Methods The stress ditribution of abutment and peridontal tissue of attachment dentures with aveolar ridge resorption  of abutment at different levels  were measured respectively,and  were compared with cantilever fixed bridge by three-dimensional finit element method.Results The stress peach of abutment and peridontal tissue of cantilever fixed bridge was （3.63E+5）Mpa.The stress peach of abutment and peridontal tissue of attachment dentures was (1.27E+5)Mpa with normal aveolar ridge and it was  lower than that of cantilever fixed bridge;the peach of abutment and peridontal tissue was(3.87E+5)Mpa when aveolar ridge was absorbed by 1/3,and it was lihgtly higher  than that of cantilever fixed bridge,;the peach was (1.38E+6)Mpa when aveolar ridge was absorbed by 1/2,and it was significantly higher than that of cantilever fixed bridge.Conclusion The extralcolonal attachment dentures could decrease the stress of abutment and peridontal tissue,the more the aveolar ridge of abutment is absorbed,the greater the stress of abutment is;when the aveolar ridge of abutment was normal,it is suitable to retore mandibular  single distal -extention absence with extralcolonal denture of C4C5 abutment designed singly,when the aveolar ridge of abutment is absorbed by 1/3,the method  should be used carefully,it is necessary to decrease  lateral forces;when the aveolar ridge of abutment is absorbed by 1/2,the method is not suitable and it is necessary to increase the number of abutmenta and use bilateral design.

Key words: three-dimensional finit element;extracoronal attachment denture;abutment peridontal tissue;aveolar ridge;stress