[Biomechanical principles of endosseous screw implants]

The present paper uses the finite element (FE) method to examine the influence exerted by the cortex layer thickness, the implant material, the implant dimensions and the thread form on the tensions developing within the bone around the implant. In the construction of an appropriate screw special attention must be paid to high rigidity of the implant, rather than to thread design, so that any kind of pointed ends are avoided. Firm incorporation of the screw by way of osseointegration should exist only in the spongiosa area and continuously decrease towards the bone surface.