Oral Tissues as Source for Bone Regeneration in Dental Implantology

One of the most common problems in Regenerative Medicine is the regeneration of damaged bone with the aim of repairing or replacing lost or damaged bone tissue by stimulating the natural regenerative process. Particularly in the fields of orthopedic, plastic, reconstructive, maxillofacial and craniofacial surgery there is need for successful methods to restore bone. From a regenerative point of view two different bone replacement problems can be distinguished: large bone defects and small bone defects. Currently, no perfect system exists for the treatment of large bone defects. Autologous bone material from the hip or the split calvarial graft is the gold standard to repair bone defects, as it has osteoinductive and osteoconductive properties (Tessier, 1982; Tessier et al., 2005a; Laurencin et al., 2006). Unfortunately this method is associated with an additional invasive intervention that leads to an increase risk of infection, pain during recovery, morbidity and frequent long periods of convalescence due to surgical trauma. Besides, only a limited amount of tissue can be obtained and harvested (Younger & Chapman, 1989; Tessier et al., 2005b). Also, the outcome is not always satisfactory after surgical treatment using bone splits (Baltzer et al., 2000; Lietman et al., 2000; Sorger et al., 2001). Heterologous transplants on the other hand, bear the risk of infection and rejection of the donor material. If the required amount of implant material cannot be obtained, another source is bovine-derived xenografts. There is, however, a potential risk for prion infection that cannot be totally avoided. Last not least large bone defect replacement needs nutrient and oxygen supply via blood vessels, so angiogenesis must be considered. This is very different in small bone defects: here angiogenesis is not an issue, but most of the other problems addressed above do play a role here too. This chapter will focus on small bone defects, especially those linked to dental implants.