ارزيابي توزيع فشار پيرامون ايمپلنت هاي دنداني در دو روش بار اتچمنت به وسيله المان محدود

A Finite-element Analysis of Stress Distribution around Dental Implant in Different Bar-attachment Systems

Sta tement of Problems: When implants are used to support an over denture, the optimal stress distribution is desirable to minimize the forces on the implants. Purpose: The purpose of this study was to compare stress patterns generated around implant supported over denture with two different bar attachment systems ITl (Dolder) and OT with finite element method. Materi als and Method : In this descr iptive study, the stress distr ibution around dental implants in an edentulous mand ible with two different bar attachment systems lOT without spacer and IT! (Do lder) with spacer) was calculated by means of three-dimensional, finite-element model of an entire lower jaw. This model was provided with two endosseo us implants in the canine region. The implants were connected to a 2 mm bar height and a vertical force was app lied to the first left molar and gradually increase d from a to SON. Then, resultant stress distribution was eva luated. Result: In OT and IʹTl (Dolder) bar attachments, the maximum von Mises stress values were observed in the cortical bone adj acent to the implant neck and this value was higher for OT bar (6.1l4M pa) than ITI (Do lder) bar attachment (3.896 Mpa). Conclusion: This 3-D FE study suggested that the use of ITI (Do lder) bar attachment with spacer is more adva ntageo us than OT bar attachment for implant-supported overdenture with regard to optimizing stress distribution.