Polymeric and inorganic nanoscopical antimicrobial fillers in dentistry.

This contribution is focused on the influence of build orientation on hardness of materials sintered using direct metal laser sintering (DMLS) technology. It builds on the current research works that has monitored the influence of build orientation on a fatigue life, mechanical properties, roughness after machining, etc. In the mentioned work, a slight influence of build orientation on the above properties was shown. The hardness was measured on a Ti6Al4V alloy which was made of powder by DMLS technology. The individual materials were sintered at different laser powers, then annealed to remove internal stresses. Part of the experiment examined the metallographic analysis of materials in the direction perpendicular to the sintered layers and parallel with the sintered layers. Microhardness was measured on metallographic cross-sections and the results were statistically processed. The influence of laser power on a respective material hardness was assessed by one-way analysis of variance (ANOVA), a comparison of the hardness between sintered and sintered-annealed samples, as well as the comparison of hardness in the two considered directions was performed by t-test and F-test. A statistically significant difference in the hardness of the materials prepared at different laser powers was found. The influence of heat treatment, as well as the direction of material building also showed a statistically significant difference.

https://www.mdpi.com/2075-4701/7/8/318/pdf

Influence of Build Orientation, Heat Treatment, and Laser Power on the Hardness of Ti6Al4V Manufactured Using the DMLS Process

Despite many discussions about Ti versus Zr, Ti remains the golden standard for dental implants. With the extended use of implants, their rejection in peri-implantitis due to material properties is going to be an important part of oral health problems. Extended use of implants leading to a statistical increase in implant rejection associated with peri-implantitis raises concerns in selecting better implant materials. In this context, starting in the last decade, investigation and use of TiZr alloys as alternatives for Ti in oral dentistry became increasingly more viable. Based on existing new results for Ti16Zr (Roxolid) implants and Ti50Zr alloy behaviour in oral environments, this paper presents the trends of research concerning the electrochemical stability, mechanical, and biological properties of this alloy with treated and untreated surfaces. The surface treatments were mostly performed by anodizing the alloy in various conditions as a non-sophisticated and cheap procedure, leading to nanostructures such as nanopores and nanotubes. The drug loading and release from nanostructured Ti50Zr as an important perspective in oral implant applications is discussed and promoted as well.

The Trends of TiZr Alloy Research as a Viable Alternative for Ti and Ti16 Zr Roxolid Dental Implants

Abstract Non-alloy quality case-hardening steels are used for low-load components made on automatic machining centers (automatic lines). Because of the widespread use of these steel in open constructions, they are exposed to atmospheric corrosion. The study attempted to analyze the effect of 20% aqueous NaCl solution on the roughness of the steel as a result of corrosion. The steel roughness and corrosion wear were determined according to corrosion time.

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Roughness of 1.0721 steel after corrosion tests in 20% NaCl

Effect of beetroot (Beta vulgaris L. var conditiva) fiber filler and corona treatment on cassava starch films properties

AISI 316Ti is Cr-Ni-Mo austenitic stainless steel stabilized by Ti, recommended for construction of various industrial and medicine devices. In spite of its high Pitting Equivalent Resistance Number (PREN=23.688) it underlies local corrosion namely pitting in aggressive chloride environment. Appearance and extent of AISI 316Ti corrosion damage in a particular chloride solution depends strongly on temperature and surface treatment. One part of tested specimens is surface untreated the second part is treated by nitric acid passivation. Specimens are immersed for 24 hours at the temperatures of 30, 50 and 80 °C in 0.3M FeCl3 solution to induce pitting. Pitting corrosion morphology (shape and size of corrosion pits) is observed viewed from above and in profile as well, by optical metallographic microscope and scanning electrone microscopy SEM. Shape and size of corrosion pits is compared in dependence on temperature and surface finish of specimens.

/pdf/variability-of-local-corrosion-attack-morphology-of-aisi-4u5d0fufxi.pdf

Variability of Local Corrosion Attack Morphology of AISI 316Ti Stainless Steel in Aggressive Chloride Environment

Abstract Temperature is considered a complicated external factor of the susceptibility of stainless steels to the pitting. This paper deals with the corrosion behaviour of AISI 316Ti stainless steel in temperature range 22 - 80°C in aggressive chloride environments (3 and 5% FeCl3 solutions). The corrosion resistance of tested steel is evaluated on the base of results of exposure immersion tests and cyclic potentiodynamic tests. According to the obtained results the resistance of AISI 316Ti to the pitting is markedly affected by temperature changes in the range 22 – 80°C. Intensity of corrosion attack increases with the rise of Cl− concentration. Gentle changes of temperature and Cl− concentration cause significant differences in character of local damage. The appearance of pitted surfaces changes with the rise of the temperature (a density of pitting increases, a size of pits decreases). The strongest change in appearance is observed between 40 and 50ºC.

Influence of temperature on corrosion resistance of austenitic stainless steel in cl containing solutions

Analysis of Fractured Screw Shaped Ti6Al4V Dental Implant

Composite Materials Based on pa Reinforced Glass Fibers

Austenitic stainless steels are widely used for various biomedical applications because of their biocompatibility, high resistance to uniform corrosion and suitable mechanical properties. However, they are prone to local corrosion in aggressive halides environments. This article focuses on the effect of fluoride added to physiological saline solution (0.05 % NaF resp. 0.5 % NaF + 0.9 % NaCl solution) and on the effect of fluoride containing mouthwash (0.05 % NaF) on corrosion resistance of AISI 316L surgical steel. Evaluation is based on results of 42-days exposition immersion tests performed at the temperature of 37 °C (REM observation of attacked surfaces, mass losses of specimens) and on the results of the electrochemical cyclic potentiodynamic polarisation tests performed in the same solutions at the same temperature.

/pdf/corrosion-resistance-of-cr-ni-mo-stainless-steel-in-chloride-10l6l69465.pdf

Lenka Markovičová

Papers

Variability of Local Corrosion Attack Morphology of AISI 316Ti Stainless Steel in Aggressive Chloride Environment

Influence of temperature on corrosion resistance of austenitic stainless steel in cl containing solutions

Analysis of Fractured Screw Shaped Ti6Al4V Dental Implant

Composite Materials Based on pa Reinforced Glass Fibers

Corrosion resistance of Cr-Ni-Mo Stainless Steel in Chloride and Fluoride Containing Environment