Fiber Reinforced Composite versus Metallic Frameworks for Implant Supported Mandibular Overdentures. (Stress Analysis)

Abstract

This study was undertaken to analyze and compare the induced stresses at the osseointegrated implants, superstructures, prosthesis and the implant-bone interface area when utilizing two patterns of denture base reinforcement for the implant supported mandibular overdentures; the glass fiber reinforced composite and metallic frameworks. Two dimensional finite element method was implemented to built up the mesh model with element number= 7411 and total nodal number= 22791. 1 Newton load was exerted to the assembly in the axial direction to the long axes of the supporting implants and in the lateral (oblique) distomesially direction of 45 degree to the long axes of the supporting implants. It was found that the oblique load induced higher stresses, while the axial load resulted in better distributed stress and the glass fiber reinforced denture base induced highest stresses at the implant-prosthesis complex as well as at the implant-bone interface area with strain values near the borderline of the pathologic overload zone of the bone more than the metallic reinforced denture base. It was concluded that, this is may be attributed to the differences in the elastic moduli of the different patterns of denture base reinforcement and the high rigid prostheses are recommended because the use of low rigid predicts largest stresses at the implant-bone interface. The elastic moduli are 25.57 GPa for the glass fiber reinforced and 45. 76 GPa for the metallic reinforced denture base.