Objective      To compare the structure and osteogenic activity between polymethyl methacrylate (PMMA) bone cement-induced membrane and calcium phosphate bone cement-induced membrane.       Methods      Totally

32 healthy adult New Zealand white rabbits were randomly divided into a PMMA bone cement group and a calcium phosphate bone cement group

16 rabbits in each group. B

one defects (15 mm) were formed on the bilateral radius of the rabbits

and then PMMA or calcium phosphate bone cement was implanted. In the 4th and 6th weeks

the induced membranes were taken out from 2 rabbits in each group to observe the film thickness and blood vessel density. The bone cement was removed in the 4th week and autogenous cancellous bone was implanted. In the 8th and 12th weeks

new bone formation was evaluated by radiological and histological observation.       Results      The thickness of the induced membranes in the PMMA bone cement group was 1 108±26 μm and 945±42 μm in the 4th and 6th weeks

respectively

while that was 945±34 μm and 778±22 μm in the calcium phosphate bone cement group (P0.05). In the 4th and 6th weeks

the blood vessel density was 6/cm

2

and 3/cm

2

in the PMMA bone cement group

and 2/cm

2

and 2/cm

2

in the calcium phosphate bone cement group

respectively. The radiological observation showed that Lane-Sandhu X-ray scores (2.84±0.36

4.22±0.54) of the PMMA bone cement group in the 8th and 12th weeks were better than those (1.98±0.15

1.98±0.23) of the calcium phosphate bone cement group (P0.05). The histological observation showed that the Nilsson histological scores (3.14±0.29

4.63±0.37) of the PMMA bone cement group in the 8th and 12th weeks were better than those (2.10±0.18

3.59±0.21) of the calcium phosphate bone cement group (P0.05).       Conclusion      The PMMA bone cement-induced membrane shows better vascularization capability and osteogenic activity than the calcium phosphate bone cement-induced membrane.