Synthesis And Evaluation Of Bioactive Compound Titanium Implant Surface For Dental Applicationon

Dental implant has become a routine treatment method in dental application nowadays. However, the traditional Branemark implant, i.e. smooth surface titanium implant shows some drawbacks in practice due to its inert surface. The bonding power may not strong enough under occlusion force. Furthermore, it needs at lest a 3-month stress-free healing period. Many researchers tried to optimize the titanium implant surface so that it is given much better biocompatibilities. A new rough and bioactive compound titanium-based implant surface was synthesized and evaluated in this study by the way of apatite inducing ability test, biocompatibility assessment in vitro and in vivo implantation assessment.1. Assessments on topography and apatite forming ability in simulated body fluid of compound implant surfaceOBJECTIVE: To produce rough and alkali-heated compound titanium implant surface and evaluate its ability of inducing apatite formation in simulated body fluid. METHODS: Pure titanium discs were got and four kinds of surface treatments were applied: 1 smooth surface (S), polished with sandpaper to 600 grind. 2 rough surface (R), smooth titanium discs were sandblasted and etched with oxalic acid. 3 smooth alkali-heated surface (SA). 4 compound surface (rough alkali-heated surface) (RA). The topography, roughness and wettability of the four kinds of surfaces were analyzed and then they were socked in simulated body fluid (DMEM+10% PCS). In the 6th, 12th, 18th and 24th day, one disc from each group was got and analyzed with SEM and EDX. Furthermore, the substance on SA and RA discs in the 24th day was analyzed with XRD and XPS. RESULTS: In smooth surface only regular polished grooves could be seen. While holes in different dimension formed in rough surface. Porous framework on the surface of the SA and nanoscale needle-like crystals on RA were found. EDX showed thatthe smooth and rough surface were consisted of 100% Ti, while there was lots of oxygen and sodium in alkali-heated surfaces. No apatite formed on the S and R group in all time period. But apatite core appeared in the 6th day on SA and RA group. The core of RA group was nanoscale needle like crystal. The cores became many tiny spheres with time and finally became larger spheres and then they fused to rough plane with cracks. While in SA group, the core was little grind at first; they fused into a block at last. The apatite deposition speed on RA group was more faster that that of SA group. It was mainly consisted of HA with XRD and XPS analysis. The surface roughness was not changed significantly by alkali-heated treatment, while surface energy was increased in the process. CONCLUSION: Sandblast and acid etching change surface topography so that holes in different diameters form. A bioactive TiOa hydrogel layer exists by alkali and heated procedure. The layer can induce HA formation in the simulated body fluid. The HA deposited on RA is nanophase needle like crystal and the deposition speed is faster than that of SA. The surface roughness is not changed significantly by alkali-heat treatment, while surface energy is increased in the process.2. Study on the biocompatibility of compound titanium surfaceOBJECTIVE: To assess the biocompatibility of compound titanium implant surface. METHODS: Compound titanium surface was synthesized and smooth titanium was used as control in all experiments. Three biological tests were done. First, hemolysis test: the hemolysis rate of the diluted rabbit blood in compound surface steep was measured to evaluate the blood compatibility of the surface according to the standard YY/T 0127. Second, cytotoxicity test, L929 cell line was cultured in different cell culture medium steeps: compound surface, smooth titanium surface as negative control and pure lead as positive control. MTT assay was used to evaluate the living cell number in the 2nd, 4th, and 6th day. The OD value in different steeps was statistically compared. Third, test of local effects after implantation: the SA and S surface titanium discs were implanted...