Analysis of the Interface Between Plasma-Sprayed Calcium Phosphate Coating and Ti-6Al-4V

1996 ◽  
Vol 458 ◽  
Author(s):  
Eunsung Park ◽  
David T. Hoelzer ◽  
Robert A. Condrate

ABSTRACTPlasma sprayed calcium phosphate coatings on Ti(alloy) have been considered advantageous over the uncoated Ti as dental implants or orthopedic prostheses due to their abilities to decrease healing time, attach firmer to the bone, and inhibit ion release from the Ti substrate. However, the coating was found not to adhere well to the Ti substrate, presumably because there is no or little chemical bonding between the calcium phosphate coating and the Ti substrate. The interfacial bond strength relies almost entirely on the mechanical locking of calcium phosphate splats onto the roughened Ti surface. In this study, the interfacial area between the calcium phosphate coating and the Ti-6A1–4V substrate was characterized using SEM and TEM. The results revealed the presence of amorphous calcium phosphate layer at the interface, which is believed to be responsible for the low bond strength. Also small particles were observed which were embedded in the amorphous phase near the interface. The presence of the amorphous phases is very important since they are more easily attacked by the physiological solution than crystalline phases are.

2019 ◽  
Vol 17 (1) ◽  
pp. 228080001982651 ◽  
Author(s):  
Thuy-Duong Thi Nguyen ◽  
Yong-Seok Jang ◽  
Min-Ho Lee ◽  
Tae-Sung Bae

Background: Titanium biomedical devices coated with strontium-doped calcium phosphate ceramics can support desirable bone regeneration through anabolic and anti-catabolic effects of strontium and the compositions close to that of natural mineral tissue. Methods: Strontium was doped into the calcium phosphate coating using the cyclic pre-calcification method on the anodized titanium plate. The effects of the different concentration of strontium in treatment solution and cycle numbers of the pre-calcification treatment on the biocompatibility were investigated in terms of the changes in morphology and chemical composition of coating, ion release pattern and cytocompatibility in vitro. Results: At a high substitution ratio of strontium in the calcium phosphate coating, the size of precipitated particles was decreased and the solubility of the coating was increased. ASH55 group, which was coated by pre-calcification treatment of 20 cycles in coating solution with Sr:Ca molar ratio of 5:5, exhibited superior cellular attachment at 1 day and proliferation after 7 days of culturing in comparison with the non-doped surface and other doped surfaces. Conclusion: Sufficient strontium doping concentrations in calcium phosphate coating can enhance cell adhesion and proliferation on the titanium biomedical devices for bone regeneration.


2009 ◽  
Vol 631-632 ◽  
pp. 211-216 ◽  
Author(s):  
Kyosuke Ueda ◽  
Takayuki Narushima ◽  
Takashi Goto ◽  
T. Katsube ◽  
Hironobu Nakagawa ◽  
...  

Calcium phosphate coating films were fabricated on Ti-6Al-4V plates and screw-type implants with a blast-treated surface using radiofrequency (RF) magnetron sputtering and were evaluated in vitro and in vivo. Amorphous calcium phosphate (ACP) and oxyapatite (OAp) films obtained in this study could cover the blast-treated substrate very efficiently, maintaining the surface roughness. For the in vitro evaluations of the calcium phosphate coating films, bonding strength and alkaline phosphatase (ALP) activity were examined. The bonding strength of the coating films to a blast-treated substrate exceeded 60 MPa, independent of film phases except for the film after post-heat-treatment in silica ampoule. When compared with an uncoated substrate, the increase in the ALP activity of osteoblastic SaOS-2 cells on a calcium phosphate coated substrate was confirmed by a cell culture test. The removal torque of screw-type Ti-6Al-4V implants with a blast-treated surface from the femur of Japanese white rabbit increased with the duration of implantation and it was statistically improved by coating an ACP film 2 weeks after implantation. The in vitro and in vivo studies suggested that the application of the sputtered ACP film as a coating on titanium implants was effective in improving their biocompatibility with bones.


2007 ◽  
Vol 361-363 ◽  
pp. 907-910
Author(s):  
Marco A. Lopez-Heredia ◽  
Borhane H. Fellah ◽  
Paul Pilet ◽  
C. Leroux ◽  
M. Dorget ◽  
...  

Porous Titanium Scaffolds were produced by using a rapid prototyping technique. These scaffolds were either coated or not with a calcium phosphate coating via an eletrodeposition method. Rat bone marrow mesenchymal stem cells were cultured on the scaffolds at a density of 106 cells/scaffold for a period of 3 days. Cell proliferation was measured by using the Alamar Blue assay. The scaffolds were observed by SEM and polarized light microscopy. Constructs were then implanted subcutaneously for 4 weeks in syngenic rats. Cells proliferated well after seeding. After subcutaneous implantation, histology and SEM revealed the presence of uniform coatings as well as Ca and P deposits in the non-coated scaffolds suggesting mineralization.


2021 ◽  
Vol 13 (1) ◽  
pp. 10-19
Author(s):  
Chun-Yan Zhang ◽  
Hao-Lan Fang ◽  
Xin-Peng Liu ◽  
Fan-Cheng Meng ◽  
Zhong-Qing Tian ◽  
...  

In order to explore the hydrothermal growth mechanism of hydroxyapatite (HA) coating on fluorinated magnesium alloy, the changes of morphology, composition and crystal phase of the calcium phosphate coating during the hydrothermal treatment were studied. And the change of electrochemical impedance spectroscopy (EIS) of the coating specimen of different hydrothermal treatment time was discussed to further understanding the change of the coating structure. The results demonstrated that calcium phosphate could rapidly nucleate on fluorinated AZ31 magnesium alloy. The crystal phase of calcium phosphate coating was mainly octacalcium phosphate (OCP) at the early stage of hydrothermal treatment. Then the content of OCP decreased and the content of HA increased with hydrothermal time. The coating consisted of only HA after hydrothermal treatment for about 4h. The HA coating composed of rod-like crystals exhibited an obvious double layer structure. The rod-like crystals of inner layer arranged into dense bundles and the rod-like crystals of outer layer arranged into loose chrysanthemum-like clusters. Fluoride conversion layer acted as an intermediate transition layer to connect magnesium alloy and HA coating into a whole. The results of immersion test in simulated body fluid demonstrated that HA crystals dissolved slowly. No peeling occurred of HA coating during the 12 days' immersion. Pitting corrosion was still the mainly corrosion mode of magnesium alloy substrate due to the electrolyte infiltration during the immersion.


2011 ◽  
Vol 410 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Tatsuya Miyazaki ◽  
Satoshi Miyauchi ◽  
Takahisa Anada ◽  
Hideki Imaizumi ◽  
Osamu Suzuki

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