Development of the principle of guided tissue regeneration.

Guided tissue regeneration (GTR) is a new treatment principle in surgical therapy, developed from the result of studies in experimental animals. It implies that only those types of cells with the capacity of producing regeneration are allowed to invade the surgically treated lesion during healing. This is accomplished by the placement of a physical barrier with excludes undesirable types of tissue. Healing of periodontal bony lesions can be obtained predictably by treatment according to the principle of guided tissue regeneration but several studies have suggested that the same principle can also be applied successfully in other fields of dentistry. In implantology, the method has been used for immediate placement of implants into extraction sockets, for healing of peri-implant bony defects and for augmentation of atrophic alveolar ridges.