Meurman J H, Voegel J C, Rauhamaa-Mäkinen R, Gasser P, Thomann J M, Hemmerle J, Luomanen M, Paunio I, Frank R M
Department of Cariology, University of Helsinki, Finland.
Caries Res. 1992;26(2):77-83. doi: 10.1159/000261433.
The aim of this study was to determine the crystalline structure and chemical alterations of synthetic hydroxyapatite after irradiation with either CO2, Nd:YAG or CO2-Nd:YAG combination lasers at high energy densities of 500-3,230 J.cm2. Further, dissolution kinetics of the lased material were analysed and compared with those of unlased apatite. Electron microscopy showed that the lased material consisted of two kinds of crystals. From the micrographs their diameters varied from 600 to 1,200 A and from 3,000 to 6,000 A, respectively. The larger crystals showed 6.9-Angström periodic lattice fringes in the transmission electron microscope. alpha-Tricalcium phosphate (TCP) was identified by X-ray diffraction. Selective-area electron diffraction identified the large crystals to consist of tricalcium phosphate while the smaller crystals were probably hydroxyapatite. Assays of dissolution kinetics showed that at these high energy densities lased material dissolved more rapidly than unlased synthetic hydroxyapatite due to the higher solubility of TCP.
本研究的目的是确定在500-3230 J.cm²的高能量密度下，用CO2、Nd:YAG或CO2-Nd:YAG组合激光辐照后合成羟基磷灰石的晶体结构和化学变化。此外，分析了激光处理材料的溶解动力学，并与未激光处理的磷灰石进行了比较。电子显微镜显示，激光处理材料由两种晶体组成。从显微照片来看，它们的直径分别在600至1200埃和3000至6000埃之间变化。在透射电子显微镜中，较大的晶体显示出6.9埃的周期性晶格条纹。通过X射线衍射鉴定出α-磷酸三钙（TCP）。选区电子衍射确定大晶体由磷酸三钙组成，而较小的晶体可能是羟基磷灰石。溶解动力学分析表明，在这些高能量密度下，由于TCP的溶解度较高，激光处理材料的溶解速度比未激光处理的合成羟基磷灰石更快。
