The placement of fixtures (implants) in relation to the geometry of a prosthetic restoration has a great influence on the mechanical loading of the implant. Based on theoretic consideration and clinical experiences with the Brånemark System, this article gives simple guidelines for controlling these loads. The emphasis is on design rules that can be used in clinical practice. With the Class I lever as a reference, various clinical implant prosthesis situations are discussed and evaluated. Schlagwörter: Brånemark implant, cantilever, fixture position, force, load, moment