抄録
Alpha-tricalcium phosphate (α-TCP) has been investigated extensively as an artificial bone graft; however, the relationship between size of α-TCP particles and its bone-formation capability is not clear. In the present study, we compared the bone-formation capability of two different sized porous α-TCP particles (α-TCP200 [under 200 μm], and α-TCP600 [500–600 μm]) in critical-sized bone defects in mouse calvaria up to 12 wk after implantation. Scanning electron microscopy revealed that both particles possessed similar smooth surface with porous structure. Before implantation, inter-particle size and specific surface area of α-TCP200 were 27 μm and 0.40 m2/g and of α-TCP600 were 209 μm and 0.24 m2/g, respectively. Histomorphometric analysis after implantation of the particles revealed that both particles promoted osteoconduction. At 12 wk, α-TCP200 induced superior bone formation than α-TCP600. At 4 wk, α-TCP200 showed more hydrolysis than α-TCP600. These results indicate that the size of α-TCP particles may influence their bone-formation capability in critical-sized bone defects of mouse calvaria. This effect might be partially due to the difference in the hydrolysis speed of different-sized particles.
