Ablation of hydroxyapatite by pulsed laser irradiation

Baeri, P.; Torrisi, L.; Marino, Nino; Fóti, G.

doi:10.1016/0169-4332(92)90046-z

Cited by 74 publications

(26 citation statements)

References 10 publications

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“…Although most of the research related to PLD of hydroxyapatite was based on the use of a KrF excimer laser ( ‫ס‬ 248 nm), 1,9-11,13 a ruby laser ( ‫ס‬ 694 nm) has also been used, 2,7,8 and good results have been obtained with an ArF excimer laser ( ‫ס‬ 193 nm). 4,11,12 Moreover, the fundamental wavelength of a Nd:YAG laser and its harmonics (1.064 m, 355 nm, and 266 nm) have been used to ablate tricalcium phosphate with different absorptivities to study the relationship between the absorption of the target and the droplet areal density on the coatings.…”

Section: Introductionmentioning

confidence: 99%

“…It was not until the beginning of the nineties that pulsed laser deposition (PLD) was proposed as a new technique to improve the quality of the HA coatings. [1][2][3][4] The products of the lasertarget interaction are atoms, molecules, small aggregates, and large particulates or droplets, with a high ratio of ions. By varying the laser beam characteristics and the nature of the target, the presence and proportion of these populations can be changed.…”

Section: Introductionmentioning

confidence: 99%

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Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

et al. 1999

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Calcium phosphate coatings, obtained at different deposition rates by pulsed laser deposition with a Nd:YAG laser beam of 355 nm wavelength, were studied. The deposition rate was changed from 0.043 to 1.16 Å/shot by modification of only the ablated area, maintaining the local fluence constant to perform the ablation process in similar local conditions. Characterization of the coatings was performed by scanning electron microscopy, x-ray diffractometry, and infrared, micro-Raman, and x-ray photoelectron spectroscopy. The coatings showed a compact surface morphology formed by glassy grains with some droplets on them. Only hydroxyapatite (HA) and alpha-tricalcium phosphate (␣-TCP) peaks were found in the x-ray diffractograms. The relative content of ␣-TCP diminished with decreasing deposition rates, and only HA peaks were found for the lowest rate. The origin of ␣-TCP is discussed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

et al. 1999

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“…Time and spatial resolved spectra have revealed that under the experiment conditions emission is mostly due to calcium neutral atoms and calcium oxide molecular radicals. Imaging of the plume with the aid of bandpass filters has demonstrated that the emissive species in the larger and faster plasma cloud are calcium neutral atoms whereas in the smaller and slower one are calcium oxide molecular radicals.Pulsed laser deposition (PLD) is a good technique to deposit thin films of complex compounds, and many authors [1][2][3][4][5][6] have used it to obtain hydroxyapatite (HA) coatings for medical prostheses. This motivated us to study the HA laser ablation process through the characterization of the plume by fast intensified CCD imaging.…”

mentioning

confidence: 99%

“…Pulsed laser deposition (PLD) is a good technique to deposit thin films of complex compounds, and many authors [1][2][3][4][5][6] have used it to obtain hydroxyapatite (HA) coatings for medical prostheses. This motivated us to study the HA laser ablation process through the characterization of the plume by fast intensified CCD imaging.…”

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confidence: 99%

Species resolved analysis of the expansion of hydroxyapatite laser ablation plumes

Serra

Morenza

1998

J. Mater. Res.

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The plume generated by ablation of hydroxyapatite targets under ArF excimer laser irradiation has been investigated by means of fast intensified charge coupled device (CCD) imaging and optical emission spectroscopy. Results have shown that the plume splits into two plasma clouds as it expands. Time and spatial resolved spectra have revealed that under the experiment conditions emission is mostly due to calcium neutral atoms and calcium oxide molecular radicals. Imaging of the plume with the aid of bandpass filters has demonstrated that the emissive species in the larger and faster plasma cloud are calcium neutral atoms whereas in the smaller and slower one are calcium oxide molecular radicals.Pulsed laser deposition (PLD) is a good technique to deposit thin films of complex compounds, and many authors [1][2][3][4][5][6] have used it to obtain hydroxyapatite (HA) coatings for medical prostheses. This motivated us to study the HA laser ablation process through the characterization of the plume by fast intensified CCD imaging. 7,8 The resultant pictures of the plasma generated by ArF excimer laser irradiation of HA targets revealed the presence of two different emissive regions. Thus, in this paper we develop a more comprehensive analysis of the HA laser ablation plume by means of time and space resolved optical emission spectroscopy in addition to fast intensified CCD imaging in order to characterize better the ablation process and to identify the nature of both regions.An ArF excimer laser (Lambda Physik LPX 205i) provides pulses at a wavelength of 193 nm, with duration of 23 ns, and energy of 300 mJ. The beam is limited by a 12 3 2 mm 2 mask and impinges at an angle of 45 ± onto a pellet made from HA powder pressed at 6 3 10 8 Pa at room temperature. The fluence on the target is about 1.5 J͞cm 2 . All the experiments are carried out in a high vacuum chamber evacuated to a base pressure of 5 3 10 25 mbar. Images are taken with a gated CCD camera (ANIMATER-VI from ARP France), 288 3 384 pixels, 8 bits dynamic range, intensified by a microchannel plate (MCP) whose aperture is delayed by a pulse generator triggered by a fast photodiode that is activated by the laser pulse. Bandpass filters (MicroCoatings Inc.) centered at 520 and 600 nm with a FWHM of 10 nm are also used in some of the recorded images and, in these cases, accumulations of 20 shots are needed to acquire an image. Otherwise, pictures are taken in a single shot mode.The optical emission spectra are acquired by means of a 0.5 m spectrometer (Chromex 500IS/SM). The laser-generated plume is imaged onto the entrance slit in such a way that the propagation axis of the plume remains parallel to this slit. This allows good spatial resolution (0.03 mm) to be obtained with the CCD camera, with no lens/mirror translation system needed. A 600 g͞mm grating blazed at 400 nm provides a spectral resolution of 0.3 nm. Each spectrum consists of the accumulation of the light emitted by the plume after 20 laser shots. The synchronization system is the same as that descri...

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“…Últimamente, la ablación láser se ha aplicado con éxito para la producción de recubrimientos de fosfato calcico de diferente composición, estructura y cristalinidad (9)(10)(11)(12). A este respecto, la técnica de ablación láser parece ser capaz de resolver los problemas intrínsecos del método de plasma-spray.…”

Section: Introductionunclassified

Producción de recubrimientos de fosfato cálcico mediante ablación láser para aplicaciones biomédicas

et al. 1998

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Resumen Los fosfatos calcicos apatíticos se utilizan como recubrimientos para mejorar la fijación de implantes ortopédicos y dentales. La técnica comercial para la producción de estos recubrimientos (plasmaspray) presenta problemas de adherencia y control de propiedades físico-químicas. En esta comunicación, se presenta la ablación láser como alternativa para solventar estos problemas. El sistema de ablación consiste en una cámara de vacío llena de vapor de agua hasta la presión deseada. El haz de un láser excímero de ArF se focaliza en un blanco de hidroxiapatito, depositándose el recubrimiento en un substrato paralelo al blanco mantenido a una cierta temperatura. Las propiedades físico-quími-cas del material se analizaron por espectroscopia infrarroja por transformada de Fourier (FT-IR), difracción de rayos X (XRD), microscopía electrónica de barrido (SEM) y espectroscopia de rayos X por dispersión de energías (EDX). Basándose en estos resultados, se escogieron dos tipos de recubrimientos para determinar su biocompatibilidad in vitro.Palabras clave: Ablación láser. Recubrimiento. Fosfato calcico. Implante. Production of calcium phosphate coatings by láser ablation for biomedical applications AbstractApatitic calcium phosphates are used as coatings to improve the fixation of orthopaedic and dental implants. The commercial technique to produce these coatings (plasm-spray) shows some problems of adherence and control of their physicochemical properties. In this communication láser ablation is presented as a solution to overeóme these problems. The ablation system consists in a vacuum chamber filled with water vapour up to the desired pressure. The láser beam of an ArF excimer láser is focused on a hydroxyapatite target, and the coating is deposited on a substrate parallel to the target maintained at certain temperature. The physicochemical properties of the material were analysed by Fourier transformed infrared spectroscopy (FT-IR) X ray diffraction (XRD), scanning electrón microscopy (SEM), and energy dispersive X ray spectroscopy (EDX). Taking into account these results, two types of coatings were choosen to asses their biocompatibility in vitro.

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Ablation of hydroxyapatite by pulsed laser irradiation

Cited by 74 publications

References 10 publications

Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

Species resolved analysis of the expansion of hydroxyapatite laser ablation plumes

Producción de recubrimientos de fosfato cálcico mediante ablación láser para aplicaciones biomédicas

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