Abstract:

Objective To observe the effect of the size of calcined bone particles on osteoconduction and study its influence in osteogenesis． Methods According to the sizes of calcined bone particles they were divided into four groups: small particle group (group A, 0.1-0.3 mm),medium particle group(group B,0.3-0.6 mm),large particle
 group(group C,0.6-0.9 mm) and mixed particle group(group D,0.1-0.9 mm).Then they were rooted in the defective cranial of rabbit respectively .In the postoperative period of 3,6,8 and 12 weeks the materials wereadoped to carry on improved Gomori special dyeing and general histologic observation,light density (A) values of new bone formation integral were determined. Results The results of the improved Gomori special dyeing showed that amount of capillary grew and new bone formation in different degrees was found.Both group A and group D  diplayed mature callus formation. The A values of each group had an  increasing tendency.The A values in group A and group D were significantly higher thanthose in group B and group C (P< 0.05) at each time points . The A values in group A were significantly higher than those in group D(P< 0.05) in 3 and 6 weeks and lower than those in group D in 9  and 12 weeks (P< 0.05). Conclusion The calcined bone  particles with different sizes  all play distinct roles in new bone formation. The effects on new bone fromation in  group A and  group D are stronger than those in group B and  group D. But the effect in  group D displays a stronger osteogenesis in the later period. It indicates that the size of calcined bone particles could be one of important indexes to screen and construct scaffold material in bone tissue engineering．

Key words: calcined bone, osteogenesis;skull defect