Comparison of deproteinized bovine bone, bioglass and, synthetic hydroxyapatite in the bone healing of a critical sized bone defect. Preliminary study in rats.

Abstract

Bone grafts are important for alveolar bone height and volume preservation necessary for dental implant placement. The development of biomaterials for bone grafting with comparable characteristics and biological effects than those renowned internationally is necessary. Deproteinized bovine bone putty (BB), bioglass (BG) and, synthetic hydroxyapatite (SH) are frequently indicated as bone grafting materials due to their osteoconductive properties. We compared the bone healing response of BB, BG and SH (Odontit Implant Systems, Argentina) in a critical sized bone defect. We created a bone defect of 4 mm diameter in rat tibiae for implantation with each biomaterial (N=30 rats). Samples were collected at 2 and 4 weeks for histological and histomorphometrical analysis of new bone formation (NBF) and remaining particles of each device (RP). Radiographic analysis was done at T=0 and at 2 and 4 weeks. Results: % of NBF (mean ± SD): 2 weeks: Control group: 6.60±3.71; BB group: 23.23±3.89*; BG group: 18.35±5.23*; SH group: 26.27±9.30*; 4 weeks: Control group: 6.69±2.38; BB group: 24.37±3.66*; BG group: 17.45±6.64*; SH group: 32.25±3.80*. % of RP: 2 weeks: Control group: 0±0; BB group: 5.04±1.39*; BG group: 3.03±2.31*; SH group: 4.46±2.87*; 4 weeks: Control group: 0±0; BB group: 4.45±2.35*; BG group: 2.87±1.14*; SH group: 3.78±1.68* (*p<0.05 versus control group; p= NS between BB, BG and SH groups). Although SH exhibited a trend towards increased NBF we did not find statistical significance among the three biomaterials. Bone healing at the implanted sites, was accompanied by a progressive inflammatory response consistent with the expected histological stages of bone repairing. The 3 biomaterials exhibited an increased in radiopacity at 2 and at 4 weeks vs. control group indicating NBF. All biomaterials were associated with trabecular bone formation. Although further studies need to be done, our results indicate that BB, BG and SH exhibit similar osteoconductive properties. Keywords: Bone healing; biomaterials; critical sized bone defect; bovine bone; bioglass; synthetic hydroxyapatite.