Deproteinized cancellous bovine bone (Bio-Oss) as bone substitute for sinus floor elevation. A retrospective,histomorphometrical study of five cases

OBJECTIVES: To study in detail the performance of deproteinized cancellous bovine bone (DPBB, Bio-Osso) granules as a bone substitute, a histomorphometric was performed on five patients treated with DPBB for reconstruction of the severely atrophic maxilla. MATERIAL AND METHODS: DPBB was used as mixture with autogenous bone particles, in concentrations that increased from 20% to 100% DPBB, with the time of healing increasing accordingly from 5 to 8 months. A total of 20 vertical biopsies was taken at the time of fixture installation and used for histomorphometry as undecalcified Goldner stained sections. RESULTS: The results show that in all cases, the DPBB granules had been interconnected by bridges of vital newly formed bone. The volume of bone in the grafted area correlated inversely with the concentration of DPBB grafted, and varied between 37% and 23%. However, the total volume of mineralized material (bone plus DPI3B granules) remained within the same range in all five patients (between 53% and 59%). The high values for osteoid and resorption surface, and the presence of tartrate-resistant acid phosphatase-positive multinucleated osteoclasts in resorption lacunae, indicated that bone remodeling was very active in all grafts. Osteoclasts were also observed in shallow resorption pits on DPBB surfaces. The percentage DPBB surface in contact with bone remained stable at about 35% and could not be related to the proportion of DPBB grafted. CONCLUSION: Although the number of patients examined was limited, the data suggest that deproteinized cancellous bovine bone, preferably combined with autogenous bone particles, is a suitable material for sinus floor elevation in the severely atrophic human maxilla.