بررسي توزيع تنش در استخوان آلويول اطراف ايمپلنت تحت تاثير عرضهاي مختلف كانتليورينگ با كولينگوالي سوپراستراكچر درمانهاي ايملنت ITI به روش اجزا محدود

Evaluation of Stress Distribution Around Bone of Implant Due to Influence of the Cantilever Buccolingually Variable Widths of Superstructure in Implant Therapies (III)Using the Finite Element Method

The purpose of this study, is the evaluation of stress distribution around bone of implant due to influence of the cantilever buccolingually variable widths of superstructure in implant therapies (ITI) using the Finite Element Method. For this research, three different conditions : with cantilever 3.5 , 5 , 7mm associated with one 12mm fixture on the anterior of the maxilla, designed by ANSYS 5.4 Software. Then, the differences between principal normal and VonMises stresses due to three oblique, axial and lateral forces each 50 and 70 Ne"l on were analyzed by two and three dimensional finite element analysis. The results indicated that stress concentration in three conditions due to the three forces, were mainly. at the crest of cortical bone The maximum vonmises stress in bone-implant interface in the first. Second and third condition due to oblique force (50 Newl on) were . 1 8.1 Mpa. 2] Mpa. 24.6 Mpa respectively. wl l ereas the maximum vonmises stress in first, second and third condition due to oblique force (7() Newton) were 25.3 Mpa , 27.7 Mpa, 34.5 Mpa respectively. The amount of the stress obtained due to axial forces were much less than the stress related to oblique forces. Whereas the stress obtained due to lateral forces was more than the stress related to oblique forces. Since the stress more than 29 Mpa in bone-implant intcrtʹace produce fatigue fracture and destruction of osseointegration , the thiru condition (7mm cantilevered) due to oblique force (70 Newton) and also the second and third condition due to lateral force (70 Newton) cause rrohlcms and it will lead to the failure of treatment.