Substituted Hydroxyapatite, Glass, and Glass-Ceramic Thin Films Deposited by Nanosecond Pulsed Laser Deposition (PLD) for Biomedical Applications: A Systematic Review

Abstract

The deposition of thin films of bioactive materials is the most common approach to improve the bone bonding ability of an implant surface. With this purpose, several wet and plasma assisted deposition methods were proposed in the scientific literature. In this review, we considered films obtained by nanosecond Pulsed Laser Deposition (PLD). Since hydroxyapatite (HA) has composition and structure similar to that of the mineral component of the bone, the initial studies focused on the selection of experimental conditions that would allow the deposition of films that retain HA stoichiometry and crystallinity. However, biological apatite was found to be a poorly crystalline and multi-substituted mineral; consequently, the attention of researchers was oriented towards the deposition of substituted HA, glass (BG), and glass-ceramic (BGC) bioactive materials to exploit the biological relevance of foreign ions and crystallinity. In this work, after a description of the nanosecond ablation and film growth of ceramic materials, we reported studies on the mechanism of HA ablation and deposition, evidencing the peculiarities of PLD. The literature concerning the PLD of ion substituted HA, BG, and BGC was then reviewed and the performances of the coatings were discussed. We concluded by describing the advantages, limitations, and perspectives of PLD for biomedical applications.

Surface Properties and In Vitro Corrosion Studies of Blasted and Thermally Treated Ti6Al4V Alloy for Bioimplant Applications

“…The high surface roughness of thermally treated samples is a result of strong internal stress in the oxide film, mismatching lattices, and a significant difference in thermal expansion coefficients between the rutile phase and titanium [ 17 ]. It is hypothesized that rough-textured biomaterial surfaces promote osteoblast cell adhesion and development [ 51 , 52 ]. Increased surface roughness increases the number of grain boundaries per unit area and enhances cell adhesion [ 53 ].…”

Bioactive Glass—An Extensive Study of the Preparation and Coating Methods

“…Therefore, a balance must be maintained. When the implant is used under load conditions, a high adhesion degree of coating on the substrate, high hardness, and toughness are the main mechanical properties that must be accomplished by the coatings performed [67].…”

RF Magnetron Sputtering of Substituted Hydroxyapatite for Deposition of Biocoatings

“…There are a number of methods of CaP coating deposition. These methods include plasma spraying [ 19 ], micro-arc oxidation or plasma electrolytic oxidation (PEO) [ 20 , 21 ], laser ablation [ 22 ], and RF magnetron sputtering [ 23 , 24 ]. All of the above methods have their advantages and disadvantages, but it is worth noting that today, more and more research is focused on the formation of coatings by physical vapor deposition (PVD) methods.…”