In Vitro Assessment of Hydroxyapatite and Si-Substituted Hydroxyapatite Coatings under Different VPS Conditions

2008 ◽  
Vol 396-398 ◽  
pp. 345-348 ◽  
Author(s):  
Qian Tang ◽  
Roger Brooks ◽  
Serena Best
Keyword(s):  
Input Power ◽  
Precipitation Method ◽  
Human Osteoblast ◽  
Lower Plasma ◽  
Plasma Gun ◽  
Vacuum Plasma ◽  
Hydroxyapatite Coatings ◽  
Phase Pure ◽  
Plasma Sprayed

Hydroxyapatite and silicon-substituted hydroxyapatite powers were prepared in-house through a wet precipitation method and then vacuum plasma sprayed onto Ti-6Al-4V discs. Two plasma gun input powers were employed, 37 kW and 40 kW. All coatings were nearly phase pure, except small traces of impurities (TTCP, -TCP and CaO). Coatings prepared under the lower plasma gun input power had lower crystallinity. In vitro studies showed that human osteoblast-like cells attached and spread very well on all coated discs. Among the four kinds of discs, SiHAC37 was the most supportive to cell growth.

Analysis of corrosion behaviour and surface properties of plasma-sprayed composite coating of hydroxyapatite–tantalum on biodegradable Mg alloy ZK60

2019 ◽  
Vol 53 (19) ◽  
pp. 2661-2673 ◽  
Author(s):  
Balraj Singh ◽  
Gurpreet Singh ◽  
Buta Singh Sidhu
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
Corrosion Behaviour ◽  
Surface Hardness ◽  
Mg Alloy ◽  
Hydroxyapatite Coating ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed ◽  
Incremental Increase

Magnesium (Mg) and its alloys are promising candidates for biodegradable bio-implants. However, the excessive corrosion in the physiological environment and subsequent decline in the mechanical integrity of Mg and its alloys have limited their utility as biomaterials. In the present study, an attempt has been made to improve the corrosion resistance of Mg alloy ZK60 plasma sprayed with tantalum (Ta)-reinforced hydroxyapatite coating. The experiment was conducted with three varied levels, i.e. 10, 20 and 30 weight percent (wt%) of Ta-content in hydroxyapatite coating. The coatings were characterized and in vitro corrosion behaviour was investigated by electrochemical measurements in Ringer's solution along with the analysis of surface properties. The corrosion resistance of the Mg alloy increased with the incremental increase in Ta reinforcement in hydroxyapatite coating. An increase in the protection efficiency was analysed for the Ta-reinforced hydroxyapatite coatings (∼10%, 18% and 23% for hydroxyapatite-10Ta, hydroxyapatite-20Ta and hydroxyapatite-30Ta, respectively) as compared to the pure hydroxyapatite coating. The hydroxyapatite coating effectively increased the surface hardness of the Mg alloy and Ta reinforcement further enhanced it. Surface roughness decreased with the incremental increase in Ta-content in hydroxyapatite coating. Wettability analysis revealed the hydrophilic nature of pure hydroxyapatite and Ta-reinforced hydroxyapatite coatings. The results of the study suggest that the proposed Ta reinforcement in hydroxyapatite is potentially important for biodegradable Mg bio-implants.

Bioactivity of Plasma-Sprayed Diopside Coating In Vitro

2005 ◽  
Vol 288-289 ◽  
pp. 319-322 ◽  
Author(s):  
Wei Chang Xue ◽  
Chuan Xian Ding ◽  
Cong Cao ◽  
Yuqi Dong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Proliferation ◽  
Cross Section ◽  
Body Fluid ◽  
Human Osteoblast ◽  
Suitable Candidate ◽  
Plasma Sprayed ◽  
Scanning Electron

A new bioceramic coating based on diopside was prepared by plasma spraying. The surface and cross-section microstructure of the coating were examined by scanning electron microscopy. The thermal expansion coefficient of the diopside coating measured by a dilatometer adapted to that of titanium alloy. The bond strength of the coating was about 32.5 MPa, which is higher than that of HA coatings used in orthopedics and dentistry. The bioactivity of diopside coating was evaluated in vitro. After 15 days soaking in simulated body fluid, an apatite layer was formed on the surface of the coating. The cytocompatibility was investigated by studying the behaviour of human osteoblast cultured directly onto the surface of the coating. MTT assay was performed to assess the influence of the coating on cell proliferation. The morphologies of the cell were observed by SEM after incubation for 1 and 7 days. The results obtained indicated that plasma sprayed diopside coating may be a suitable candidate for bone and dental implant.

In vitro andin vivo biological responses of plasma-sprayed hydroxyapatite coatings with posthydrothermal treatment

2007 ◽  
Vol 83A (2) ◽  
pp. 263-271 ◽  
Author(s):  
C. Y. Yang ◽  
T. M. Lee ◽  
C. W. Yang ◽  
L. R. Chen ◽  
M. C. Wu ◽  
...  
Keyword(s):  
Biological Responses ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed

In Vitro Cytocompatibility of Silver-Containing Hydroxyapatite Coatings

2009 ◽  
Vol 620-622 ◽  
pp. 567-570 ◽  
Author(s):  
Yi Kai Chen ◽  
Xue Bin Zheng ◽  
Baoe Li ◽  
You Tao Xie ◽  
Chuan Xian Ding ◽  
...  
Keyword(s):  
Contact Angle ◽  
Antibacterial Property ◽  
Water Drop ◽  
Contact Angles ◽  
Hydroxyapatite Coating ◽  
Vacuum Plasma Spraying ◽  
Vacuum Plasma ◽  
Hydroxyapatite Coatings ◽  
Spraying Method

In this paper, antibacterial silver-containing hydroxyapatite coating was prepared by vacuum plasma spraying method and osteoblasts were seeded onto the surface of the coating to evaluate its cytocompatibility. The results indicated that the cells proliferated well on the samples, and the proliferation rate on the silver-containing hydroxyapatite coating was a little bit higher than that on the silver-free hydroxyapatite coating. The contact angle of water drop on the coating was measured, and it was found that the contact angles of the silver-containing hydroxyapatite coatings were smaller than the hydroxyapatite coating. The improvement of hydrophilicity for the silver-containing hydroxyapatite coating could be beneficial to the cells proliferation on its surface. It can be concluded that the addition of silver in the hydroxyapatite coating endowed the coating with antibacterial property while maintaining its excellent cytocompatibility.

In Situ Characterization of Degradation Behavior of Plasma-Sprayed Coatings on Orthopedic and Dental Implants

2006 ◽  
Vol 49 ◽  
pp. 203-211 ◽  
Author(s):  
Racquel Z. LeGeros ◽  
John P. LeGeros
Keyword(s):  
Calcium Phosphate ◽  
Dental Implants ◽  
Calcium Phosphates ◽  
Interfacial Strength ◽  
Precipitation Method ◽  
Calcium Phosphate Coating ◽  
Implant Surface ◽  
Ha Coating ◽  
Plasma Sprayed

Plasma-sprayed ‘HA’ coatings on commercial orthopedic and dental implants were developed to combine the strength of the metal (Ti or Ti alloy) and the bioactivity of the hydroxyapatite (HA). Several studies have shown that ‘HA’-coated implants provided greater amount of bone attachment, higher bone-implant interfacial strength and accelerated skeletal attachment. However, some reports on implant failures have been attributed to coating delamination and coating early resorption of the plasma sprayed ‘HA’ coating. This paper reviews studies on characterization and degradation of plasma-sprayed ‘HA’ coatings on orthopedic and dental implants and offers alternatives to plasma-spray method of providing calcium phosphate coating. X-ray diffraction analyses showed that plasma-sprayed HA coating consists principally of HA and amorphous calcium phosphate (ACP) with minor amounts of other resorbable calcium phosphates (α- or β-tricalcium phosphates, tetracalcium phosphate), sometimes calcium oxide. The HA/ACP ratios were found to range from 20HA/80ACP to 70HA/30ACP in coated implants from different manufacturers. In vitro initial dissolution rates in acidic buffer (pH 6, 37oC) increased with decreasing HA/ACP ratios in the coating because of the preferential dissolution of the ACP phase. These results suggest that coating with very low HA/ACP ratio may result in the premature resorption of the coating before the bone can attach to the implant thus causing loosening and eventual failure of the implant. Alternatives to plasma-sprayed ‘HA’ are implant surface modifications and low temperature calcium phosphate coatings using electrochemical deposition method or precipitation method.

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