Abstract
Decomposition product of hydroxyapatite irradiated by CO2 laser with energy of 300〜24000J/cm2was examined by X-ray powder diffraction method.In the X-ray diffraction patterns a few peaks of α-and β-tricalcium phosphate were observed at 800J/cm2.The products lased with 3200〜24000J/cm2 were composed of 75wt% hydroxyapatite, 21wt% α-, and 4wt% β-tricalcium phosphate.The lased product and hydroxyapatite powder heated at 500〜1300℃ were incubated at 37℃ in pH 7.4 Tris-HCl buffer.Ca concentration of these solutions were measured.The solubility of lased product with 24000J/cm2 was found to be 3 to 5 times as large as that of hydroxyapatite.The product lased with 24000J/cm2 and hydroxyapatite powder heated at 700℃ were injected into tibia of Whister rats.The animals were sacrificed at 1, 2, 3, 4, and 5 weeks and investigated histrogically.New bone tissues were grown around the lased products as well as hydroxyapatite.
