The development of dental implantology is based on the detailed study of the interaction of implants with the surrounding tissues and methods of osteogenesis stimulation around implants, which has been confirmed by the increasing number of scientific publications presenting the results of studies related to both the influence of the chemical composition of dental implant material as well as the method of its surface modification on the key operational characteristics of implants. The main materials for dental implant manufacturing are Ti and its alloys, stainless steels, Zr alloys (including ceramics based on ZrO₂), and Ta and its alloys, as well as other materials (ceramics based on Al₂O₃, Si₃N₄, etc.). The review presents alloy systems recommended for use in clinical practice and describes their physical–mechanical and biochemical properties. However, when getting into the body, the implants are subjected to various kinds of mechanical influences, which are aggravated by the action of an aggressive biological environment (electrolyte with a lot of Cl⁻ and H⁺); it can lead to the loss of osteointegration and to the appearance of the symptoms of the general intoxication of the organism because of the metal ions released from the implant surface into the biological tissues of the organism. Since the osteointegration and biocompatibility of implants depend primarily on the properties of their surface layer (it is the implant surface that makes contact with the tissues of the body), the surface modification of dental implants plays an important role, and all methods of surface modification can be divided into mechanical, physical, chemical, and biochemical methods (according to the main effect on the surface). This review discusses several techniques for modifying dental implant surfaces and provides evidence for their usefulness.

The functional role of nano-dispersed multi-layered composite coatings (NMCC) deposited on the working surfaces of cutting inserts (CI) made of the layered high-strength ceramic (LHC) to equip the cutting tools when cutting hardened (high-strength) steels was investigated. It is shown that the variation in the composition, structure and properties of coatings allows controlling the contact processes at cutting, increasing the length of contact, reducing normal contact stresses and probability of micro- and macro-brittle failure of tool cutting edge. The mathematical models of cutting which establish dependences of flank wear land of the tool, the tangential component of cutting force, power of cutting and roughness of the machined surface from conditions of cutting of high-strengthen steels are developed. It is found out that the application of nano-dispersed ceramic multi-layered coatings on ceramic tool significantly increases its wear resistance and improves the quality of machining.

The paper studies the influence of properties of a tool made of mixed ceramic by applying modifying with nanoscale multi-layered coatings on machinability of hardened tool steel XVG. The paper also examines the influence of cutting speed on wear resistance of mixed ceramic with nanoscale multilayered coatings. The mathematical models that found out the dependence of tool life of a ceramic tool with coating from cutting speed were developed.

This review considered various methods for depositing special modifying coatings on medical implants made of titanium alloys including techniques such as electrochemical deposition, sol–gel process, atmospheric plasma deposition, and PVD methods (magnetron sputtering and vacuum arc deposition). The rationale is provided for the use of modifying coatings to improve the performance efficiency of implants. The concept of a functional multilayer coating designed for products operating in the human body environment is proposed. The advantages and disadvantages of various methods for depositing coatings are considered based on the possibility of their use for obtaining modifying coatings for medical purposes deposited on a titanium alloy base.

In this work, the mechanical properties and corrosion resistance of Cr-CrN, Ti-TiN, Zr-ZrN, and Mo-MoN coatings deposited by the physical vapor deposition (PVD) method on Ti-6Al-4V alloy were compared. The phase composition of the coatings, their hardness and fracture resistance in scratch tests were determined, and their structural characteristics were also studied using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The diffraction spectra were made using an automatic X-ray diffractometer. The value of the adhesive component of the friction coefficient f_adh of the pair “coated and uncoated Ti-6Al-4V alloy” was investigated in the temperature range of 20–900 °C. The lowest value of f_adh was detected for the Zr-ZrN coating at temperatures below 400 °C, while for the Mo-MoN coating it was observed at temperatures above 700 °C. The polarization curves of the coated and uncoated samples were performed in a 3% aqueous NaCl solution. The level of corrosion of the Ti-6Al-4V alloy samples with Cr-CrN, Ti-TiN, Zr-ZrN, and Mo-MoN coatings was evaluated using the Tafel extrapolation method, the iteration method, and the polarization resistance method. The results obtained with these methods indicate that the Zr-ZrN coated sample has the best corrosion resistance in the 3 wt.% NaCl solution, with a corrosion current density of 0.123 μA/cm².

The article discusses the influence of the thickness of the wear-resistant layer of the Zr-ZrN-(Zr,Al,Si)N nanolayer composite coating on the values of residual stress and the nature of coating wear. The study focused on coatings with wear-resistant layer thicknesses of 2.0, 4.3, 5.9, and 8.5 µm, deposited using filtered cathodic vacuum arc deposition (FCVAD) technology. The X-ray diffraction (XRD) method based on the anisotropy of the elasticity modulus was used to find the values of the residual stress. The nature of the formation of interlayer delamination under the influence of residual compressive stress was studied using a scanning electron microscope (SEM). When the wear-resistant layers had a thickness of 2.0–5.9 μm, tensile stress formed, which decreased with an increase in the thickness of the coating. When the thickness of a wear-resistant layer was 8.5 μm, compressive stress formed. Under the action of compressive stress, periodic interlayer delamination formed, with a pitch of about 10 binary nanolayers. A mathematical model is proposed to describe the nature of the formation of interlayer delamination under the influence of compressive residual stress, including in the presence of a microdroplet embedded in the coating structure.