scholarly journals Fretting and Fretting Corrosion Processes of Ti6Al4V Implant Alloy in Simulated Oral Cavity Environment

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1561
Author(s):  
Marcin Klekotka ◽  
Jan Ryszard Dąbrowski ◽  
Katarzyna Rećko
Keyword(s):  
Artificial Saliva ◽  
Open Circuit ◽  
Fretting Wear ◽  
Dissipated Energy ◽  
Titanium Oxides ◽  
X Ray Diffraction ◽  
Fretting Corrosion ◽  
Pin On Disc

The paper presents the results of in vitro studies of fretting and fretting corrosion processes of Ti6Al4V implant alloy in the environment of natural saliva and self-made mucin-based artificial saliva solutions. The study was performed on a specially designed fretting pin-on-disc tester, which was combined with a set used for electrochemical research. The open circuit potential measurements and potentiodynamic method were used for corrosion tests. The worn surfaces were subjected to microscopic observations and an evaluation of wear. Results were interpreted using the dissipated energy and third-body approaches. The X-ray diffraction analysis showed that titanium oxides constitute over 80% of the friction products. Special attention was paid to the role of saliva and its substitutes, which in certain cases can lead to the intensification of fretting wear. On the basis of the received results, a new phenomenological model of fretting corrosion processes was proposed. This model involves the formation of an abrasive paste that is a combination of metal oxides and the organic components of saliva.

Effects of dietary alteration of bicarbonate and magnesium on rat bone

1986 ◽  
Vol 250 (2) ◽  
pp. F302-F307 ◽  
Author(s):  
J. M. Burnell ◽  
C. Liu ◽  
A. G. Miller ◽  
E. Teubner
Keyword(s):  
Crystal Structure ◽  
Bone Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growing Rats ◽  
Final Composition ◽  
Rat Bone

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.

scholarly journals In vitro corrosion studies of stainless-steel dental substrates during Porphyromonas gingivalis biofilm growth in artificial saliva solutions: providing insights into the role of resident oral bacterium

RSC Advances ◽  
2020 ◽  
Vol 10 (52) ◽  
pp. 31280-31294
Author(s):  
Ubong Eduok ◽  
Jerzy Szpunar
Keyword(s):  
Stainless Steel ◽  
Porphyromonas Gingivalis ◽  
Artificial Saliva ◽  
Biofilm Growth ◽  
Corrosion Studies ◽  
Oral Bacterium ◽  
Culture Suspension

A stainless-steel 321 dental substrate significantly corroded within Porphyromonas gingivalis growth culture in artificial saliva culture suspension, with and without NaF additive.

Electrochemical Determination of the Corrosion Resistance of Ag-Pd Dental Alloys

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Daniel Mareci ◽  
Igor Cretescu ◽  
Neculai Aelenei ◽  
Julia Claudia Mirza Rosca
Keyword(s):  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Artificial Saliva ◽  
Surface Film ◽  
Electrochemical Determination ◽  
Open Circuit ◽  
Electrochemical Characteristics

The electrochemical behavior of a three Ag-Pd alloys used in dental prosthetics construction for crowns and bridges was studied in artificial saliva using the polarization curves and electrochemical impedance spectroscopy (EIS). The corrosion resistance was evaluated by means of the corrosion currents value and by coulometric analysis. The open circuit potential of Ag-Pd are attributed to dealloying followed by surface enrichment with Ag and the possible formation of an insoluble AgCl surface film on the respective alloy surfaces. Our results have shown that these alloys have a somewhat good corrosion resistance in artificial saliva. When increasing the content of Cu, corrosion resistance decreases. The passivation of all samples occurred spontaneously at the open circuit potential. The electrochemical properties of the spontaneously passivated electrodes at the open circuit potential were studied by EIS. The polarization resistance (Rp) and the electrode capacitance (Cdl) were determined. The polarisation resistance of all the samples increases with the immersion time. The polarization resistances are largest and decrease when increasing the content of Cu. Cu reduces the Ag-Pd alloy corrosion resistance. The present study, thought limited, has shown that electrochemical characteristics can be use to identify such alloys. Knowledge of the in vitro corrosion behaviour of these alloys may lead to better understanding of any biologically adverse effects in vitro.

scholarly journals The effect of Streptococcus mutans on the Corrosion Behavior of Nickel-Titanium Dental Alloys - In Vitro Study

2019 ◽  
Vol 8 (6) ◽  
pp. 435-440
Author(s):  
Asmaa Marda ◽  
Khadija Mouflih ◽  
Abdelkebir Bellaouchou ◽  
Abdallah Guenbour ◽  
Asmae Elmansari ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Oral Bacteria ◽  
Open Circuit ◽  
Nickel Titanium ◽  
Dental Alloys ◽  
Enrichment Medium

This study aimed to compare the resistance of dental alloys to corrosion in a solution containing oral bacteria named Streptococcus mutans (S.mutans). The electrochemical behavior of Nickel-Titanium (NiTi) was investigated in sterile Fusayama artificial saliva (AS) with the enrichment medium tryptic soy broth (TSB) in solution 1 and (AS) with (TSB) and bacteria in solution 2. The electrochemical procedures selected for this work were open circuit potentials (OCP), Potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The NiTi surface was examined using optical microscopy.      After 24 hours of immersion in artificial saliva, the results have shown that NiTi revealed high corrosion reactivity in the presence of S. mutans and present pitting corrosion on the surface.

Apatite Growth on Bioactive Glass in Artificial Saliva

2000 ◽  
Vol 662 ◽  
Author(s):  
Sarah E. Efflandt ◽  
Robert F. Cook ◽  
Lorraine F. Francis
Keyword(s):  
Bioactive Glass ◽  
Artificial Saliva ◽  
Apatite Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Time Period ◽  
Surface Morphologies ◽  
Surface Changes

AbstractBioactive glass disks from the MgO-CaO-P2O5-SiO2 system were placed in artificial saliva for time periods varying from 1 to 42 days. Surfaces were then analyzed using scanning electron microscopy (SEM) and x-ray diffraction to investigate surface morphologies and crystallinity. SEM examination exhibited dramatic surface changes as early as 2 d. X-ray results showed crystallinity in the form of apatite at 10 d, which became more developed though 42 d. The bioactive glass in water and non-bioactive glass in artificial saliva were used as controls; both exhibited no evidence of apatite formation on their surfaces through the 42 d time period. This study shows that bioactive glass reacts in artificial saliva to form apatite and that the apatite layer becomes better crystallized over an extended time period. These results give a better understanding of the surface changes and mineralization that occur over time and can be used to interpret results from in vitro and in vivo studies done on bioactive glass in the oral environment.

Role of active potassium transport by integumentary epithelium in secretion of larval-pupal moulting fluid during silkmoth development

1975 ◽  
Vol 62 (2) ◽  
pp. 357-366
Author(s):  
A. M. Jungreis ◽  
W. R. Harvey
Keyword(s):  
Short Circuit ◽  
Flux Ratio ◽  
Short Circuit Current ◽  
Potassium Transport ◽  
Open Circuit ◽  
Ratio Test ◽  
Potassium Flux

1. The exuvial side of the pharate pupal integument is usually positive to the haemolymph-side, both in vivo and in vitro, during the period when the moulting fluid is being secreted. 2. The ratio of potassium flux toward the exuvial space is higher than that toward the haemolymph, under both open-circuit conditions and short-circuit conditions, demonstrating by the Flux Ratio test that potassium is actively transported across the isolated integument during this secretion period. 3. Just prior to ecdysis, while moulting fluid is being reabsorbed, the potassium flux ratios become unity, suggesting that active potassium transport has ceased, but the short-circuit current that remains suggests that some other ion is actively transported at this time. 4. We argue that the potassium salt solution, formed in the exuvial space (as water presumably follows the actively transported potassium), has three functions (1) to accomplish the gel--sol transformation, (2) to activate the gel enzymes and (3) to buffer the enzyme solution at a pH favourable to the activity of the gel enzymes.

The Role of Crystallographic Texture of Ti-6Al-4V Alloy on Cell Attachment and Proliferation

2005 ◽  
Vol 495-497 ◽  
pp. 705-710 ◽  
Author(s):  
S. Faghihi ◽  
M.R. Bateni ◽  
Fereshteh Azari ◽  
Jerzy A. Szpunar ◽  
H. Vali ◽  
...  
Keyword(s):  
Crystallographic Texture ◽  
Cell Attachment ◽  
Proliferation Rate ◽  
Osteoblastic Cell ◽  
X Ray Diffraction ◽  
Joint Replacements ◽  
In Vitro Systems ◽  
Cell Adhesion And Proliferation

Owing to their lower modulus, great corrosion resistance and superior biocompatibility, titanium alloys are increasingly used as artificial joint replacements. However bone bonding capability of these materials needs to be improved. Many studies are currently conducted to improve the osseo-integration of titanium based implants. In the present study, the role of crystallographic texture of titanium alloy Ti-6Al-4V on bone bonding capability was investigated in vitro systems. X-ray diffraction analysis was used to determine preferred orientation in each substrate. These substrates were seeded with preosteoblast cells to examine cell attachment and proliferation. Attachment of cells was assessed by counting the number of adhered cells within 30-240 min. The proliferation rate of cells was measured between the 3rd-11th days of incubation. The results suggest that the substrate with (100) orientation shows better osteoblastic cell adhesion and proliferation rate than the (110).

Study on the Effects of Type I Collagen Combined with Noncollagenous Proteins on Hydroxyapatite Formation in vitro using SPM and GIXD

2009 ◽  
Vol 1238 ◽  
Author(s):  
Xiaolan Ba ◽  
Elaine DiMasi ◽  
Miriam H Rafailovich
Keyword(s):  
Type I Collagen ◽  
Early Stage ◽  
Cooperative Interaction ◽  
Type I ◽  
X Ray Diffraction ◽  
Noncollagenous Proteins ◽  
Force Microscopy ◽  
Kinetics Of

AbstractThe effects of the components of extracellular matrix on the bone formation and the kinetics of crystal growth of calcium phosphate have remained unknown. In this paper, we reported a method to investigate the role of Type I collagen and the interactions with other ECM proteins such as fibronectin and elastin during biomimic mineralization process in vitro. The early stage of mineralization was characterized by scanning probe microscopy (SPM) and shear modulation force microscopy (SMFM). The late stage of mineralization was investigated by synchrotron grazing incident x-ray diffraction (GIXD). The results demonstrate the cooperative interaction between type I collagen and noncollagenous proteins such as fibronectin or elastin could be essential for the biomineralization.

scholarly journals Acidic monosaccharides become incorporated into calcite single crystals

2020 ◽  
Author(s):  
Arad Lang ◽  
Sylwia Mijowska ◽  
Iryna Polishchuk ◽  
Simona Fermani ◽  
Giuseppe Falini ◽  
...  
Keyword(s):  
Crystalline Lattice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Deposition ◽  
Anisotropic Lattice ◽  
Lattice Distortions ◽  
Shed Light ◽  
Proteins And Peptides

ABSTRACTCarbohydrates, along with proteins and peptides, are known to represent a major class of biomacromolecules involved in calcium carbonate biomineralization. However, in spite of multiple physical or biochemical characterizations, the explicit role of saccharide macromolecules (long chains of carbohydrate molecules) is not yet understood in mineral deposition. In the present study we investigated the influence of two common acidic monosaccharides (MSs), which are the simplest form of carbohydrates and are represented here by glucuronic and galacturonic acids, on the formation of calcite crystals in vitro. We show that the size, morphology and microstructure of calcite crystals are altered when they are grown in the presence of these MSs. More importantly, MSs were found to become incorporated into the calcite crystalline lattice and induce anisotropic lattice distortions, a widely studied phenomenon in other biomolecules related to CaCO3 biomineralization but never before reported in the case of single MSs. Changes in the calcite lattice induced by MS incorporation were precisely determined by the technique of high-resolution synchrotron powder X-ray diffraction. We believe that the results of this research may deepen our understanding of the interaction of saccharide polymers with an inorganic host and shed light on the implications of carbohydrates for biomineralization processes.

scholarly journals In Vitro Corrosion and Tribocorrosion Performance of Biocompatible Carbide Coatings

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 654
Author(s):  
Iulian Pana ◽  
Alina Vladescu ◽  
Lidia R. Constantin ◽  
Ioan G. Sandu ◽  
Mihaela Dinu ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Substrate Roughness ◽  
Carbide Coatings ◽  
Hall Plot ◽  
Pin On Disc ◽  
Steel Substrates

The present study aims to explain the corrosion and the tribocorrosion performance in simulated conditions of the human body by the level of stress, adhesion of coating to substrate, roughness, and hardness. The coatings were synthesized by the cathodic arc evaporation method on 316L stainless steel substrates to be used for load bearing implants. Structure, elemental, and phase compositions were studied by means of energy dispersive spectrometry and X-ray diffraction, respectively. The grain size and strain of the coatings were determined by the Williamson–Hall plot method. Tests on hardness, adhesion, roughness, and electrochemical behavior in 0.9% NaCl solution at 37 ± 0.5 °C were carried out. Tribocorrosion performances, evaluated by measuring the friction coefficient and wear rate, were conducted in 0.9% NaCl solution using the pin on disc method at 37 ± 0.5 °C. TiC and ZrC exhibited a (111) preferred orientation, while TiNbC had a (200) orientation and the smallest crystallite size (8.1 nm). TiC was rougher than ZrC and TiNbC; the lowest roughness was found for TiNbC coatings. The highest hardness and adhesion values were found for TiNbC, followed by TiC and the ZrC. All coatings improved the corrosion resistance of 316L steels, but TiNbC showed the best corrosion behavior. TiNbC had the lowest friction coefficient (1.6) and wear rate (0.99 × 10−5 mm3·N−1∙m−1) values, indicating the best tribocorrosive performance in 0.9% NaCl at 37 ± 0.5 °C.

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