The clinical use of deproteinized bovine bone mineral on bone regenerationin conjunction with immediate implant installation

Twenty-one c.p. titanium screw-shaped implants were immediately installed a fter extraction and thorough curettage of the alveoli in 15 patients. Granu les of deproteinized bovine bone of 0.25-1.0 mm diameter were used to fill the remaining defect when the distance of the defect wall to the implant su rface was >3 mm. Dimensional measurements of the defect height and width we re made with a pocket probe. Fourteen sites in the upper jaw and 7 sites in the lower jaw were thus treated. The mean defect depth varied between 7 mm vestibularly and 10 mm mesially. The mucoperiosteal flaps were hermeticall y closed. At re-entry, the particles were packed and firmly attached but st ill distinguishable from the surrounding bone. Of the 21 sites treated, 5 s ites had an exposure of the implant cover screw during the healing period. An exposure of the granular material occurred in 4 sites, but loss of granu les in only 3. Even in these sites no signs of infection or inflammation of the soft tissues were observed. At re-entry after 6 months, 10 sites were completely and 9 partially filled. For the partial fills, the mean remainin g defect height was 1.6 mm (range: 0.6-3.0 mm). Two sites showed an increas ed defect of respectively 2.4 and 4.8 mm. No fixtures were lost. The presen t results indicate that deproteinized bovine bone is a safe filling materia l to fill remaining defects around implants installed in fresh extraction s ockets.