In vivo study of novel biodegradable and osteoconductive CaO-SiO2-B2O3 glass-ceramics

To evaluate the possibility of novel CaO-SiO2-B2O3 glass-ceramics (CS10B) as a new bone replacement material, we compared the biodegradation and osteoconduction properties of CS10B, hydroxyapatite (HA), and tricalcium phosphate (TCP). Porous CS10B implants were prepared by the polymer sponge method. L5-6 single-level posterolateral spinal fusions were performed on 30 New Zealand white male rabbits. The animals were divided into three groups by implant material: CS10B, HA, and TCP. Radiographs were performed every 2 weeks. All animals were euthanized 12 weeks after surgery. The ratio of the area occupied by the ceramics by final and initial radiographs was calculated using radiomorphometric analysis. Uniaxial tensile strength was determined from seven cases in each group. The ratio of the area occupied by HA (88.7% +/- 16.1%) was significantly higher than the others (p < 0.005), and the ratio of the area occupied by CS10B (28.2% +/- 9.3%) was significantly lower than those of HA and TCP (37% +/- 9.6%, p < 0.05). The mean values of the tensile strengths of the CS10B (182.7 +/- 19.9 N) and HA (191.4 +/- 33.5 N) were significantly higher (p < 0.05) than that of TCP (141.1 +/- 28.2 N). CS10B had a fusion mass tensile strength similar to that of HA. Histological analysis confirmed that CS10B was well incorporated into the fusion mass. These findings suggest that CS10B is a possible bone replacement material. (c) 2006 Wiley Periodicals, Inc.