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.

Histological observations on biopsies harvested following sinus floor elevation using a bioactive glass material of narrow size range.

We evaluated the bone augmenting capacity of bioactive glass particles, size range 300-355 microns (BG-particles), in human sinus floor elevations using histomorphometrical methods. A total of 10 patients underwent bilateral grafting, using a 1:1 mixture of autogenous bone particles (from iliac crest) and BG-particles at one side (experimental side), and bone particles only at the other side (control side, split mouth design). A total of 72 bone biopsies were taken at the time of fixture installation; that is, 3 patients at 4 months, 3 at 5 months and 3 at 6 months after grafting and 1 patient at 16 months (when she presented again). In each case 6 biopsies were taken, 3 left and 3 right. Histomorphometry showed that in grafts at control sides, trabecular bone was present after 4 months, comprising almost 41% of the tissue volume. This bone contained viable osteocytes and was of mature lamellar type and showed a mature histological appearance. Bone volume continued to increase slightly, to 42% at 5 months, 44% at 6 months and 45% at 16 months. The graft volume at experimental sides consisted at 4 months for 28% of woven and some lamellar bone, and increased to 35% at 5 months and 38% at 6 months, when mainly lamellar bone was found. At 16 months a lamellar bone volume of 45% was found. The BG-particles transformed and became excavated with time, starting at 4 months, and their centers gradually filled with bone tissue. All BG-particles had disappeared by resorption at 16 months after grafting and had been replaced by bone tissue. Parameters of bone turnover (% osteoid surface, % resorption surface, mineral apposition rate as measured by tetracycline labeling) indicated that bone remodeling was very active at both sides, during more than 6 months, despite the mature histological appearance of the bone tissue. From these histological observations, we conclude that a 1:1 mixture of autogenous bone/BG-particles seems a promising alternative to autogenous bone only, when low amounts of bone tissue are available for sinus augmentation.

[Bone quality after sinus floor augmentation]. / Botkwaliteit na sinusbodemverhoging.

The problem of insufficient alveolar bone in the edentulous maxilla caused by resorption and pneumatization can be overcome by augmentation of the sinus floor to increase bone volume for the placement of dental implants. The quality of bone which is achieved after sinus floor augmentation is hardly known. This study describes the histologic results obtained three till six months after sinus floor augmentation with autogenous bone from the iliac crest in patients with severe maxillary bone resorption. The bone biopsies taken from the implant sites showed a substantial bone volume with a mature trabecular pattern and active bone growth. It was concluded that with the obtained bone quality, the sinus floor augmentation procedure can be a good treatment modality for the rehabilitation with implants in patients with severe maxillary bone atrophy.