بررسی و مقایسه توزیع تنش سه بعدی به روش تجزیه اجزای محدود در استخوان ایمپلنت با شکل های مختلف قوس های بی دندانی در فک پایین

The geometric shape of dental arch (square, tapering, ovoid) is an important factor in stress distribution pattern around dental implant. The aim of this study was to evaluate the role of arch form and the amount of bone loss (normal, moderate, high) in stress distribution around dental implant by considering different load direction. Three arch forms square, ovoid, and tapering with three different stages of bone loss were designed. Models were divided into three-dimensional elements, which made 5500 nodes. The 143N load was applied at two angles (straight, oblique) at the last fixture, 8mm, and 16 mm from the center of implant on l!ie cantilever. The Sap90 software was used for analyzing the stress distribution in this study. 54 different conditions were evaluated. Results showed that stress concentration changed from support toward fixture due to distally changing the load in the square and ovoid arch forms with normal bone. In the tapering arch with normal bone stress concentration was around the fixture. The amount of stress in normal tapering arch was more than physiologic extend, therefore, application of cantilever in tapering arches is not recommended.