Radio Frequency Magnetron Sputter Deposition as a Tool for Surface Modification of Medical Implants

Abstract

The resent advances in radio frequency (RF)-magnetron sputtering of hydroxyapatite films are reviewed and challenges posed. The principles underlying RF-magnetron sputtering used to prepare calcium phosphate-based, mainly hydroxyapatite coatings, are discussed in this chapter. The fundamental characteristic of the RF-magnetron sputtering is an energy input into the growing film. In order to tailor the film properties, one has to adjust the energy input into the substrate depending on the desired film properties. The effect of different deposition control parameters, such as deposition time, substrate temperature, and substrate biasing on the hydroxyapatite (HA) film properties is discussed.

Calcium Phosphate Layers Deposited on Thermal Sensitive Polymer Substrates in Radio Frequency Magnetron Plasma Discharge

“…Moreover, the cytotoxic activity of the obtained material surfaces, due to toxic compound formation, was also identified [5]. Nevertheless, the osteogenic potential of amorphous and crystalline CaP coatings was demonstrated in several publications [1,4].In this paper, the results obtained from the deposited calcium phosphate layers on polyprophylene thermal sensitive polymeric substrates (with melting temperature of about 160 • C) by magnetron sputtering discharge in different experimental conditions are reported. The steady-state of the discharge and the proper parameters for the deposition of such coatings on polypropylene samples were identified by monitoring the deposition rate signal fluctuations with time.…”

“…Calcium phosphate ceramic coatings represent a class of biomaterials widely used in biomedical applications, such as bone substitution and bone regeneration, due to the biocompatible, non-toxic, bioresorbable properties, as well as the similarities of their chemical composition with the inorganic component of bone structures [1]. A great biocompatible material requires a good implant-bone cell connection after the insertion of the implant in the human body to sustain new bone formation, adherence to tissues and to induce the growth of peripheral tissues [1][2][3][4][5]. In recent studies it was demonstrated that the osteointegration of the orthopedic prosthesis could be increased by covering the implant surfaces with calcium phosphate (CaP) bioactive coatings, which prove to accelerate the bone-bonding rate [1,3].…”

“…A great biocompatible material requires a good implant-bone cell connection after the insertion of the implant in the human body to sustain new bone formation, adherence to tissues and to induce the growth of peripheral tissues [1][2][3][4][5]. In recent studies it was demonstrated that the osteointegration of the orthopedic prosthesis could be increased by covering the implant surfaces with calcium phosphate (CaP) bioactive coatings, which prove to accelerate the bone-bonding rate [1,3].…”

“…Moreover, the cytotoxic activity of the obtained material surfaces, due to toxic compound formation, was also identified [5]. Nevertheless, the osteogenic potential of amorphous and crystalline CaP coatings was demonstrated in several publications [1,4].…”

“…The layers generated in the 10 min plasma on/10 min plasma off deposition conditions were not cracked or exfoliated. The Fourier Transform Infrared spectra of the polyprophylene substrates presented similar molecular bands before and after the depositions of calcium phosphate layers.A large number of methods, including magnetron sputtering, thermal plasma spraying, biomimetic crystallization methods, pulsed laser deposition, sol-gel coatings or electrospinning, are currently used for the deposition of multicomponent materials, such as CaP [1,[4][5][6][7][8]. In rf magnetron sputtering discharges, such layers have been generated on different kind of substrates (metallic or polymeric) with planar or complex shapes, by maintaining the temperature at the substrate during the depositions between 50-70 • C [5,9].…”