| Objective:The aim of implants surface treatment is to improve the bone implant interface bonding strength and initial osteoinduction. The methods of implant surface reshaping are physical modification and biochemical approaches. The physical modification can make the implant-bone combined with area increases, bone integration fast, allowing bone conformity way to subprime smaller interface growth. But it has offered only suitable for cell growth of surface design, improve the ability and the lock force of the cells and not chemically bonded. Biological activation modified through the coating technology which put biological activation materials such as hydroxyapatite on the implant surface can effectively improve the bonding strength of implant-bone, realize the chemically bonded of the implant materials and body, so as to improve the adhesion strength of the implant materials and the body. The experiment will combine the two methods, preparation the implants of surface design and load Ca/P salt.,and through the animal experiments to test this implants of early osteogenesis and implant-bone bonding strength.Methods:1Through the control of the incident laser energy, pulse width and pulse quantity, the wavelength and the polarization characteristics in the center of the laser parameters and solution of the degree of saturation conditions. The femtosecond laser process cylindrical pure Ti implants surface which submerged in HA liquid, in its surface processing gives a variety of design structure and get the Ca/P active layer, unprocessed smooth cylindrical pure Ti plant body as control group.2Using scanning electron microscopy (SEM) and energy spectrum analysis implants surface morphology and the elements of surface and the attachments.3The two groups were implanted in New Zealand white rabbits tibial in vivo. The animals were to put to death after2、4、8weeks.The animals were taked X-ray1day and fluorescently labeled by muscle injection1week (30mg/Kg) before the animals were to sacrifice. The specimens were taken down with implant.Universal Mechanical Testing Machine test bone bonding strength, the other samples were prepared histologic sections to investigation early osteoarthritis and initial osteoinductive.Results:1Femtosecond laser can prepared the implants surface when wavelength800nm, pulse width50fs, scanning speed of0.2～0.8mm/s, scan line spacing for100μm.2The sample pictured structure was composed of groove and the coral shape under SEM. The load objects was revealed on surface. Energy spectrum analysis showed that the surface mainly by the elements of titanium, calcium and phosphorus,the load objects was calcium and phosphorus.The control group surface was smooth and a little mechanical processing scratched3In vivo results:The two groups of2weeks no difference, are all fibrous tissue and protein organization attachment surface. The fibrous tissue of4、8weeks was less than2weeks, sedimentary of calcium and phosphorus corresponding increase. Histological section results indicated that the osteoblasts, trabecular bone, osteoid and deposition of Calcium phosphorus salt surrounding the group implants are appeared earlier、reactions、quantity compared to the control group. The implant-bone binding force and the adhesion strength increases with the extension of time, are better than the control group in the same period.Conclutions:1The implants bathed in the HA which were processed by femtosecond laser can be synchronous get physics modification and biological chemical modification.2Choose the right laser parameters, the implant immersed in the HA saturated solution formed multilayer topological structure, including holes, grooves and coral shape structure, and Ca/P element close load on its surface.3The pure titanium implants prepared by femtosecond laser has the bone inductive,can promote the early osteogenesis and increase the bone bonding strength. |
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