A FEASIBILITY STUDY EVALUATING RHBMP-2 ABSORBABLE COLLAGEN SPONGE DEVICE FOR LOCAL ALVEOLAR RIDGE PRESERVATION OR AUGMENTATION

This two-center human clinical trial evaluated recombinant human bone morphogenetic protein-2 delivered in an absorbable collagen sponge (rh BMP-2/ACS) for either alveolar ridge preservation after tooth extracti on or augmentation of localized osseous defects. This 24-month study c omprised two parts: a 4-month acute safety and bone induction period ( Part I) followed by a 20-month, osseointegration, functional restorati on and long-term safety evaluation (Part II). The primary objective of Part I, discussed in this article, was to evaluate the short-term saf ety and technical feasibility of the rhBMP-2 device implantation. Twel ve patients (six preservation and six augmentation) were enrolled in t he investigation. Patient safety was monitored by oral examinations, r adiographs, and the collection of blood samples to measure serum chemi stries, hematology, and potential antibody formation. Technical feasib ility was evaluated by collecting information relating to the handing properties of the rhBMP-2/ACS device. The ability of various evaluativ e tools to measure the bone-inducing activity of the rhBMP-2/ACS devic e was also assessed. The clinical results suggested that rhBMP-2/ACS w as well tolerated locally and systemically with no serious adverse eve nts. The device was found to be easily handed and adapted to the ridge and extraction socket. Using direct measurements, ail sites demonstra ted firmness and fullness to palpation at 4 weeks: however a loss of v olume was noted in some treatment areas between 4 and 8 weeks. Augment ation of the alveolar ridge was not observed in the patients as assess ed by the evaluation techniques. This trial indicated that the use of rhBMP-2/ACS to preserve alveolar ridge after tooth extraction or augme ntation of localized defects is safe and feasible. Bone fill was obser ved in ail alveolar sockets filled with the rhBMP-2 device.