The expression and activity of alkaline phosphatase in human periodontal ligament cells with nanometer hydroxyapatite / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of nanometer hydroxyapatite on the proliferation and the osteogenetic differentiation of periodontal ligament cells (PDLC).</p><p><b>METHODS</b>Nano-hydroxyapatite powders were fabricated with sol-gel method. The fourth passage periodontal ligament cells were cultured with nanometer hydroxyapatite powder (nano-HA), dense hydroxyapatite powder (dense-HA) and only medium as control respectively. On the 5th, 8th day of culture, the osteogenetic differentiation of human periodontal ligament cells was evaluated though alkaline phosphatase (ALP) activity, ALP immunohistochemical stain and ALP positive flow cytometry.</p><p><b>RESULTS</b>There were significant differences among nano-HA group, dense-HA group and control group on the 5th and 8th day of culture. A majority of nano-HA group and dense-HA group cells sample showed positive ALP stain. But the ALP positive stain of nano-HA group cells sample was denser than that of dense-HA group. In FCM, the distribution of ALP positive cells cultured with nanoparticles were significantly more than that of other groups.</p><p><b>CONCLUSIONS</b>The nano-HA, as a calcium phosphate biomaterial, has ability to promote the activity of osteogenetic differentiation for periodontal ligament cells compared with dense-HA.</p>

Scanning electron microscopic study of titanium-hydroxyapatite, the functionally graded-material implanted in rabbits / 中华整形外科杂志

<p><b>OBJECTIVE</b>The purpose of this study was to observe the tissue tolerance of Ti-HA functionally graded-material (FGM) and the form of the material-bone interface.</p><p><b>METHODS</b>The sintered Ti -HA FGM, pure HA and pure Ti were respectively implanted into the parietal bone of rabbits. The specimens were observed by SEM at 2, 4, 8 postoperative weeks.</p><p><b>RESULTS</b>In the early stage, the new bone surrounding the Ti -HA FGM formed earlier with larger amount and better maturity than the pure Ti. The condition was similar to the pure HA. Two months after the operation, direct bonding of material-bone interface was formed between the Ti -HA FGM and the new bone as an integral body. However, there was a little space left between the new bone and the pure Ti.</p><p><b>CONCLUSIONS</b>The Ti -HA FGM has good tissue tolerance. Its early integration with bone is similar to pure HA and better than pure Ti.</p>