[Resorbable bone substitution materials: An overview of commercially available materials and new approaches in the field of composites].

When acquired or inborn bony defects cannot heal by the natural regeneration process due to being above the critical size or to particular diseases, e.g. osteoporosis, it becomes necessary to use bone substitute materials. These are materials which replace the missing bone tissue in host tissue and stimulate the bone healing process by mechanical and structural support either alone or in combination with other substances. This supporting effect can be attended by natural as well as artificial bone substitute materials and in a variety of ways. The biological efficiency of a bone substitute material is often classified with respect to the terms osteogenic, osteoconductive and osteoinductive stimulation. In reality however there is an overlap of several effective principles. Due to the limited availability of autologous bone and the disadvantages for the patient associated with the removal, intensive research is being carried out into artificial alternatives. The present article aims to offer some orientation in this confusing field by a systematic description of the various bone substitute materials.