ABSTRACT
BACKGROUND: Hedgehog signaling pathway is shown to contribute to the osteogenesis of bone marrow mesenchymal stem cells, and to play an important role in regulating the expression of RANKL in osteoblasts. Nowadays, the definite signal transduction pathway has been revealed gradually.OBJECTIVE: To review the research progress of RANKL in osteoblasts that regulated by hedgehog signaling pathway.METHODS: A computer-based online search in CNKI, Google Scholar and PubMed databases was performed with the key words of Hedgehog, osteoblast, BMSCs, PTHrP, CREB, NFAT, RANKL in English and Chinese, respectively.Literatures related to the expression of RANKL in osteoblasts that regulated by the Hedgehog signaling pathway were included initially and 37 eligible articles were extensively summarized for review.RESULTS AND CONCLUSION: The Hedgehog signaling pathway plays an advanced role in the osteogenic differentiation of bone marrow mesenchymal stem cells, and also upregulates intracellular parathyroid hormone related protein, which activates its downstream signaling molecules cAMP response element binding protein and nuclear factor of activated T cells ulteriorly, to promote the expression of RANKL in osteoblasts and increase the differentiation and formation from osteoclast precursor cells to mature osteoclasts.
ABSTRACT
BACKGROUND: Recently, zirconia ceramic implants have been reported to be used in clinic. Increasing studies on surface treatment of ziconia implants have been done, in order to promote bone-implant osseointegration and increase the success rate of implantation. There are no recognized surface treatment techniques of zirconia implants as yet.OBJECTIVE: To summarize the research progress in surface treatment techniques of zirconia implants.METHODS: The first author searched the CNKI, PubMed and Web of Science databases for relevant articles published from January 2000 to October 2016. The keywords were zirconia or zirconium, implant, surface treatment in Chinese and English, respectively. The search condition was((zirconia or zirconium) AND implant) AND surface treatment. Here,we reviewed the surface treatment techniques of zirconia implants, and introduced the properties, the surface treatment techniques and commercialization of zirconia implants.RESULTS AND CONCLUSION: Totally 23 papers were included in result analysis. Commonly used surface treatment technologies of zirconia implants include sand blasting, acid etching, sandblast and acid-etching, selective filtration etching, laser, ultraviolet and coating. These technologies all contribute to improving the surface activity of the implant,increasing the roughness, and promoting bone bonding to a certain extent.Because of the very limited experiments,further investigations are required to explore the optimum technique for the surface treatment of zirconia implants.