Factors influencing the preservation of the periimplant marginal bone.

Esthetic outcomes cannot be attributed to a single parameter. Rather, as this article shows, they are the result of a number of important factors, especially in the esthetic zone. An understanding of the meaning of biologic width, of the integration of the platform-switching concept into implant treatment facilitates the preservation of a stable marginal bone level around the implant neck. This stable bone then serves to support the soft tissue, determining the long-term esthetic and functional treatment outcomes stability. The following points should be noted: (1) A prefabricated post that can be used both as a temporary post and as the definitive abutment helps to avoid a frequent replacement of secondary components, provided that the 3-dimensional position of the implant is correct. It prevents a repeated destruction of the connective-tissue attachment on the biologic width, which would carry with it the risk of bone resorption. (2) A special implant and abutment design (a ledge and integration of the biologic width/tapered shape of the post) facilitates nonsurgical lengthening and thickening of the periimplant soft tissue. This leads to the establishment of a wider and more resistant zone of connective tissue. (3) A microrough and nanorough titanium surface extending to the implant shoulder in conjunction with the platform-switching concept provides osseous integration along the entire length of the implant. A fine thread optimally distributes the masticatory forces in the region of the implant neck, avoiding further bone loss in this region.