Microstructure and crystallinity in hydroxyapatite coatings

Chen, Jiyong; Wolke, J.G.C.; Groot, K. de

doi:10.1016/0142-9612(94)90253-4

Cited by 75 publications

(36 citation statements)

References 6 publications

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“…However, hydroxyapatite coatings may degrade when in contact with body fluids, resulting in poor long-term stability. An alternative technique for applying the coating is sputtering [7][8][9][10][11][12][13][14][15][16], which involves the dense and uniform deposition of nanoscale films. Sputtered HA shows high adhesive strength to the substrate [12].…”

Section: Introductionmentioning

confidence: 99%

Characteristics of RF-Sputtered Thin Films of Calcium Phosphate on Titanium Dental Implants

2017

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Hydroxyapatite (HA) coatings on titanium have been investigated for many years, and have demonstrated advantageous biocompatibility in dental implants. Animal experiments have demonstrated that the biological response to plasma-sprayed HA-coated implants shows disadvantages in terms of adherence, thickness uniformity, and long-term osseointegration effects. Determining how to resolve the degradation problem of HA in the body by improving osseointegration and stability in alveolar bones has become an increasingly researched topic. The present study investigated the film characteristics and dissolution properties of calcium phosphate (CaP) coatings obtained by radio-frequency (RF) sputtering of a self-developed atmospheric plasma spray (APS) HA target. The experimental parameters varied, including RF power (60-250 W), sputtering time (15-120 min), and substrate roughness (0.4-4 µm). Analyses were conducted using synchrotron X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), white light interferometry, and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (EDS). EDS analysis showed that the Ca/P ratio increased as the discharge power was increased. The analysis results also showed that a lower surface roughness resulted in higher crystallinity, because a larger surface-free energy was attained during sputtering. In-plane texturing has been proven when HA films are sputtered onto substrates of varying roughness, within appropriate deposition parameters. FTIR analysis revealed the presence of the principal PO 4 3− bonds in the deposited calcium phosphate films. The CaP films induced calcium phosphate precipitation when immersed in simulated body fluid (SBF), suggesting that, based on in vitro bioactive behavior, the proposed combined surface modification can be used in dental implants.

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Section: Introductionmentioning

confidence: 99%

Characteristics of RF-Sputtered Thin Films of Calcium Phosphate on Titanium Dental Implants

2017

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“…However the method proved its usefulness, its shortcoming is low cohesion of coating, especially at applying of calcium phosphate layers of large thickness. In addition at applying of CaP by method of plasma spraying the substrate temperature increases considerably that makes this method practically unsuitable for applying of CaP ceramic coating on polymer materials, on consequence of their melting and thermal destruction (Chen et al, 1994).…”

Section: Plasma Sprayingmentioning

confidence: 99%

Scaffold Materials Based on Fluorocarbon Composites Modified with RF Magnetron Sputtering

Tverdokhlebov¹,

Bolbasov²,

Shesterikov³

2012

Osteogenesis

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“…The dissolution rate of crystalline HA has been observed to be very low, while that of the amorphous phase HA is considerably high [1]. Various techniques have been used to deposit calcium phosphate on metal substrates such as sputtering, electron beam deposition, laser deposition, and plasma spraying [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. So far, plasma spraying is the only technique being commercialized and most widely used because of its simplicity and cost effectiveness.…”

Section: Introductionmentioning

confidence: 99%

“…However, the heat treatment increases the processing time and cost and can even cause residual stresses in the HA coating due to a thermal expansion mismatch between the coated layer and the metal substrate. This residual stresses may even lead to the cracking of the coating and eventual reduction in its bond strength [16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Processing and Development of Nano-Scale HA coatings for Biomedical Application

Rabiei

Thomas

2004

MRS Proc.

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Functionally graded Hydroxyapatite coating with graded Crystallinity across the thickness of the film has been processed and tested as a more effective orthopedic/ dental implant coating. The present study aims to increase the service-life of an orthopedic/ dental implant by creating materials that form a strong, long lasting, bond with the Ti substrate as well as juxtaposed bone. The health relatedness of the new material is to increase bonding between an implant and juxtaposed bone so that a patient who has received joint or dental replacement surgery may quickly return to a normal active lifestyle. Cross-sectional transmission electron microscopy analysis displayed that the films have a graded crystal structure with the crystalline layer near the substrate and the amorphous layer at the top surface. Compositional analysis was performed using SEM-EDX at the top surface as well as STEM-EDX at the cross section of the film. The average calcium to phosphorous ratio at the surface is 1.46, obtained by SEM-EDX, The Ca/P ratios in the crystalline and amorphous layers of the film are 1.6 to 1.7, close to the ratio of 1.67 for HA. INTRODUCTIONIn order to improve the bioactivity of metal implants, Hydroxyapatite (HA: CaJ0(P0 4 )

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Microstructure and crystallinity in hydroxyapatite coatings

Cited by 75 publications

References 6 publications

Characteristics of RF-Sputtered Thin Films of Calcium Phosphate on Titanium Dental Implants

Characteristics of RF-Sputtered Thin Films of Calcium Phosphate on Titanium Dental Implants

Scaffold Materials Based on Fluorocarbon Composites Modified with RF Magnetron Sputtering

Processing and Development of Nano-Scale HA coatings for Biomedical Application

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