1
|
Shankar K, Agarwal S, Mishra S, Bhatnagar P, Siddiqui S, Abrar I. A review on antimicrobial mechanism and applications of graphene-based materials. BIOMATERIALS ADVANCES 2023; 150:213440. [PMID: 37119697 DOI: 10.1016/j.bioadv.2023.213440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/01/2023]
Abstract
In recent years, graphene and its derivatives, owing to their phenomenal surface, and mechanical, electrical, and chemical properties, have emerged as advantageous materials, especially in terms of their potential for antimicrobial applications. Particularly important among graphene's derivatives is graphene oxide (GO) due to the ease with which its surface can be modified, as well as the oxidative and membrane stress that it exerts on microbes. This review encapsulates all aspects regarding the functionalization of graphene-based materials (GBMs) into composites that are highly potent against bacterial, viral, and fungal activities. Governing factors, such as lateral size (LS), number of graphene layers, solvent and GBMs' concentration, microbial shape and size, aggregation ability of GBMs, and especially the mechanisms of interaction between composites and microbes are discussed in detail. The current and potential applications of these antimicrobial materials, especially in dentistry, osseointegration, and food packaging, have been described. This knowledge can further drive research that aims to look for the most suitable components for antimicrobial composites. The need for antimicrobial materials has seldom been more felt than during the COVID-19 pandemic, which has also been highlighted here. Possible future research areas include the exploration of GBMs' ability against algae.
Collapse
Affiliation(s)
- Krishna Shankar
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Shameerpet, Hyderabad, Telangana 500078, India
| | - Satakshi Agarwal
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Shameerpet, Hyderabad, Telangana 500078, India
| | - Subham Mishra
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Shameerpet, Hyderabad, Telangana 500078, India
| | - Pranshul Bhatnagar
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Shameerpet, Hyderabad, Telangana 500078, India
| | - Sufiyan Siddiqui
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Shameerpet, Hyderabad, Telangana 500078, India
| | - Iyman Abrar
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani - Hyderabad Campus, Shameerpet, Hyderabad, Telangana 500078, India.
| |
Collapse
|
2
|
Ijaz MF, Alharbi HF, Bahri YA, Sherif ESM. Alloy Design and Fabrication of Duplex Titanium-Based Alloys by Spark Plasma Sintering for Biomedical Implant Applications. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8562. [PMID: 36500058 PMCID: PMC9740822 DOI: 10.3390/ma15238562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Very often, pure Ti and (α + β) Ti-6Al-4V alloys have been used commercially for implant applications, but ensuring their chemical, mechanical, and biological biocompatibility is always a serious concern for sustaining the long-term efficacy of implants. Therefore, there has always been a great quest to explore new biomedical alloying systems that can offer substantial beneficial effects in tailoring a balance between the mechanical properties and biocompatibility of implantable medical devices. With a view to the mechanical performance, this study focused on designing a Ti-15Zr-2Ta-xSn (where x = 4, 6, 8) alloying system with high strength and low Young's modulus prepared by a powder metallurgy method. The experimental results showed that mechanical alloying, followed by spark plasma sintering, produced a fully consolidated (α + β) Ti-Zr-Ta-Sn-based alloy with a fine grain size and a relative density greater than 99%. Nevertheless, the shape, size, and distribution of α-phase precipitations were found to be sensitive to Sn contents. The addition of Sn also increased the α/β transus temperature of the alloy. For example, as the Sn content was increased from 4 wt.% to 8 wt.%, the β grains transformed into diverse morphological characteristics, namely, a thin-grain-boundary α phase (αGB), lamellar α colonies, and acicular αs precipitates and very low residual porosity during subsequent cooling after the spark plasma sintering procedure, which is consistent with the relative density results. Among the prepared alloys, Ti-15Zr-2Ta-8Sn exhibited the highest hardness (s340 HV), compressive yield strength (~1056 MPa), and maximum compressive strength (~1470). The formation of intriguing precipitate-matrix interfaces (α/β) acting as dislocation barriers is proposed to be the main reason for the high strength of the Ti-15Zr-2Ta-8Sn alloy. Finally, based on mechanical and structural properties, it is envisaged that our developed alloys will be promising for indwelling implant applications.
Collapse
Affiliation(s)
- Muhammad Farzik Ijaz
- Mechanical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - Hamad F. Alharbi
- Mechanical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - Yassir A. Bahri
- Mechanical Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - El-Sayed M. Sherif
- Centre of Excellence for Research in Engineering Materials (CEREM), King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| |
Collapse
|
3
|
Paşahan A, Sevimli R, Kıvılcım N, Karaca Açarı İ, Erenler AŞ, Sezer S, Durmaz HT, Hüz M, Ünver T, Seçkin T, Akpolat N, Köytepe S, Gültek A, Ateş B, Yılmaz İ. Preparation, characterization, and biocompatibility of chondroitin sulfate-based sol-gel coatings and investigation of their effects on osseointegration improvement. INT J POLYM MATER PO 2022. [DOI: 10.1080/00914037.2022.2105332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- Aziz Paşahan
- Medical Services and Techniques Department, Vocational School of Health Service, Inonu University, Malatya, Turkey
| | - Reşit Sevimli
- Department of Orthopedics and Traumatology, Turgut Ozal Medical Center, Inonu University, Malatya, Turkey
| | - Nilüfer Kıvılcım
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - İdil Karaca Açarı
- Department of Bioengineering, Faculty of Engineering and Natural Sciences, Turgut Ozal University, Malatya, Turkey
| | - A. Şebnem Erenler
- Department of Medical Biology, School of Medicine, Turgut Ozal University, Malatya, Turkey
| | - Selda Sezer
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - H. Turgut Durmaz
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - Mustafa Hüz
- Department of Pathology, Turgut Ozal Medical Center, Inonu University, Malatya, Turkey
| | - Tuba Ünver
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Inonu University, Malatya, Turkey
| | - Turgay Seçkin
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - Nusret Akpolat
- Department of Pathology, Turgut Ozal Medical Center, Inonu University, Malatya, Turkey
| | - Süleyman Köytepe
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - Ahmet Gültek
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - Burhan Ateş
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| | - İsmet Yılmaz
- Department of Chemistry, Faculty of Arts and Science, Inonu University, Malatya, Turkey
| |
Collapse
|
4
|
Muñoz S, Castillo SM, Torres Y. Different models for simulation of mechanical behaviour of porous materials. J Mech Behav Biomed Mater 2018; 80:88-96. [PMID: 29414480 DOI: 10.1016/j.jmbbm.2018.01.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 12/12/2017] [Accepted: 01/26/2018] [Indexed: 12/20/2022]
Abstract
Commercially pure Titanium (cpTi) and its alloys are the most successful metallic biomaterials for bone replacement, due to its excellent biomechanical and biofunctional balance. However, these materials have higher elastic modulus when compared with bone, leading to the stress-shielding phenomenon and promoting bone resorption. Development of porous implants with low elastic modulus, providing a good mechanical and functional balance (suitable mechanical strength and optimum osseointegration), is the focus of emergent research in advanced Ti-based alloy biomaterials. With the aim of understanding the mechanical behaviour of porous materials with relation to the porosity level and the porous morphology, a new improved model with three different versions have been developed in this work. The proposed FE model combines the simplicity of a 2D periodic geometry with the complex information of the pore morphology extracted from experimentation. The methodology to generate the 2D simulated microstructure is based on a series of nxn pores distributed in a square matrix. The different versions of the model differ in the way of building the porous geometry. In the first version of the model ("Basic-Pattern Model"), the pores are supposed to be circular and periodically distributed in the matrix, following a perfect pattern. The second version of the model ("Pattern Model") is similar to the previous one, but with elliptic pores with a morphology randomly generated, following statistical information from experiments. In the third version ("Semi-random Model"), a controlled random distribution of the pores is obtained by including a randomness factors in both directions. By making use of the proposed FE model with its different versions, five different porous titanium obtained by the space-holders technique (with porosities θ = 28%, 37%, 47%, 57% and 66%) have been modeled based on experimental information of the pore morphology, and its macroscopic mechanical behaviour has been simulated, showing relatively good agreement with experimental results.
Collapse
Affiliation(s)
- S Muñoz
- Department of Engineering and Materials Science and Transportation, University of Seville, Av. Camino de los Descubrimientos s/n, 41092 Seville, Spain.
| | - S M Castillo
- Department of Engineering and Materials Science and Transportation, University of Seville, Av. Camino de los Descubrimientos s/n, 41092 Seville, Spain
| | - Y Torres
- Department of Engineering and Materials Science and Transportation, University of Seville, Av. Camino de los Descubrimientos s/n, 41092 Seville, Spain
| |
Collapse
|
5
|
Chen T, Liu D, Wu F, Wang H. Effect of CeO₂ on Microstructure and Wear Resistance of TiC Bioinert Coatings on Ti6Al4V Alloy by Laser Cladding. MATERIALS 2017; 11:ma11010058. [PMID: 29301218 PMCID: PMC5793556 DOI: 10.3390/ma11010058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/23/2017] [Accepted: 12/29/2017] [Indexed: 11/16/2022]
Abstract
To solve the lack of wear resistance of titanium alloys for use in biological applications, various prepared coatings on titanium alloys are often used as wear-resistant materials. In this paper, TiC bioinert coatings were fabricated on Ti6Al4V by laser cladding using mixed TiC and ZrO2 powders as the basic pre-placed materials. A certain amount of CeO2 powder was also added to the pre-placed powders to further improve the properties of the TiC coatings. The effects of CeO2 additive on the phase constituents, microstructures and wear resistance of the TiC coatings were researched in detail. Although the effect of CeO2 on the phase constituents of the coatings was slight, it had a significant effect on the microstructure and wear resistance of the coatings. The crystalline grains in the TiC coatings, observed by a scanning electron microscope (SEM), were refined due to the effect of the CeO2. With the increase of CeO2 additive content in the pre-placed powders, finer and more compact dendrites led to improvement of the micro-hardness and wear resistance of the TiC coatings. Also, 5 wt % content of CeO2 additive in the pre-placed powders was the best choice for improving the wear properties of the TiC coatings.
Collapse
Affiliation(s)
- Tao Chen
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
- State Key Laboratory of High Performance Complex Manufacturing, Changsha 410083, China.
| | - Defu Liu
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
- State Key Laboratory of High Performance Complex Manufacturing, Changsha 410083, China.
| | - Fan Wu
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
| | - Haojun Wang
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
| |
Collapse
|
6
|
Duarte MAT, Motta AC, Duek EADR. Caracterização de pinos da blenda poli(L-co-D,L ácido láctico)/poli(caprolactona triol) (PLDLA/PCL-T) e análise das propriedade mecânicas dos pinos durante degradação in vitro. POLIMEROS 2016. [DOI: 10.1590/0104-1428.1905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Resumo Os dispositivos de fixação óssea, metálicos convencionais, usados em cirurgia crâniomaxilofacial têm apresentado alguns problemas, tais como, corrosão, inflamação e infecção, além de neoformação de estrutura óssea mecanicamente inferior devido à atrofia gerada pela diferença de módulo elástico entre metal e osso, razões que têm levado ao aumento do interesse por dispositivos poliméricos bioarreabsorvíveis. Os polímeros biorreabsorvíveis mais utilizados nesta aplicação pertencem à família dos poli (α-hidroxi ácidos), que têm como característica degradarem por hidrólise de suas ligações ésteres, tal como copolímero poli (L-ácido láctico-co-D, L ácido láctico), PLDLA. Neste trabalho foram investigados alguns efeitos da adição de poli (caprolactona triol), PCL-T sobre PLDLA. Foram preparados pinos por fusão de blendas nas seguintes composições 100/0, 90/10, 70/30 and 50/50 (m/m), PLDLA/PCL-T. Os pinos foram caracterizados por diferentes técnicas (DSC, MEV e ensaio mecânico). A degradação in vitro dos pinos foi investigada, sendo observado que a adição de PCL-T no PLDLA modificou suas propriedades mecânicas e morfológicas. Tais mudanças podem apresentar potencial para outras aplicações do material, onde a questão da flexibilidade se faça necessária.
Collapse
|
7
|
An Investigation on the Wear Resistance and Fatigue Behaviour of Ti-6Al-4V Notched Members Coated with Hydroxyapatite Coatings. MATERIALS 2016; 9:ma9020111. [PMID: 28787911 PMCID: PMC5456493 DOI: 10.3390/ma9020111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/27/2016] [Accepted: 02/02/2016] [Indexed: 11/17/2022]
Abstract
In this study, surface properties of Ti-6Al-4V alloy coated with hydroxyapatite coatings were investigated. Wear resistance and fatigue behaviour of samples with coating thicknesses of 10 and 50 µm as well as uncoated samples were examined. Wear experiments demonstrated that the friction factor of the uncoated titanium decreased from 0.31 to 0.06, through a fluctuating trend, after 50 cycles of wear tests. However, the friction factor of both the coated samples (10 and 50 µm) gradually decreased from 0.20 to 0.12 after 50 cycles. At the end of the 50th cycle, the penetration depth of the 10 and 50 µm coated samples were 7.69 and 6.06 µm, respectively. Fatigue tests showed that hydroxyapatite coatings could improve fatigue life of a notched Ti-6Al-4V member in both low and high cycle fatigue zones. It was understood, from fractography of the fracture surfaces, that the fatigue zone of the uncoated specimens was generally smaller in comparison with that of the coated specimens. No significant difference was observed between the fatigue life of coated specimens with 10 and 50 µm thicknesses.
Collapse
|
8
|
Sun Y, Song Y, Zuo J, Wang S, Gao Z. Biocompatibility evaluation of novel β-type titanium alloy (Ti–35Nb–7Zr–5Ta)98Si2in vitro. RSC Adv 2015. [DOI: 10.1039/c5ra19767h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cell proliferation, osteoblast adhesion, morphology, differentiation, inflammatory response, apoptosis and biomineralization were investigated to evaluate the biocompatibility of (Ti–35Nb–7Zr–5Ta)98Si2 alloy.
Collapse
Affiliation(s)
- Yu Sun
- Department of Orthopaedics
- China-Japan Union Hospital of Jilin University
- Changchun 130033
- P. R. China
| | - Yang Song
- Department of Orthopaedics
- China-Japan Union Hospital of Jilin University
- Changchun 130033
- P. R. China
| | - Jianlin Zuo
- Department of Orthopaedics
- China-Japan Union Hospital of Jilin University
- Changchun 130033
- P. R. China
| | - Shengqun Wang
- Department of Orthopaedics
- China-Japan Union Hospital of Jilin University
- Changchun 130033
- P. R. China
| | - Zhongli Gao
- Department of Orthopaedics
- China-Japan Union Hospital of Jilin University
- Changchun 130033
- P. R. China
| |
Collapse
|
9
|
Li Y, Yang C, Zhao H, Qu S, Li X, Li Y. New Developments of Ti-Based Alloys for Biomedical Applications. MATERIALS (BASEL, SWITZERLAND) 2014; 7:1709-1800. [PMID: 28788539 PMCID: PMC5453259 DOI: 10.3390/ma7031709] [Citation(s) in RCA: 252] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 12/24/2013] [Accepted: 01/24/2014] [Indexed: 02/05/2023]
Abstract
Ti-based alloys are finding ever-increasing applications in biomaterials due to their excellent mechanical, physical and biological performance. Nowdays, low modulus β-type Ti-based alloys are still being developed. Meanwhile, porous Ti-based alloys are being developed as an alternative orthopedic implant material, as they can provide good biological fixation through bone tissue ingrowth into the porous network. This paper focuses on recent developments of biomedical Ti-based alloys. It can be divided into four main sections. The first section focuses on the fundamental requirements titanium biomaterial should fulfill and its market and application prospects. This section is followed by discussing basic phases, alloying elements and mechanical properties of low modulus β-type Ti-based alloys. Thermal treatment, grain size, texture and properties in Ti-based alloys and their limitations are dicussed in the third section. Finally, the fourth section reviews the influence of microstructural configurations on mechanical properties of porous Ti-based alloys and all known methods for fabricating porous Ti-based alloys. This section also reviews prospects and challenges of porous Ti-based alloys, emphasizing their current status, future opportunities and obstacles for expanded applications. Overall, efforts have been made to reveal the latest scenario of bulk and porous Ti-based materials for biomedical applications.
Collapse
Affiliation(s)
- Yuhua Li
- National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, Guangdong, China.
| | - Chao Yang
- National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, Guangdong, China.
| | - Haidong Zhao
- National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, Guangdong, China.
| | - Shengguan Qu
- National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, Guangdong, China.
| | - Xiaoqiang Li
- National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, Guangdong, China.
| | - Yuanyuan Li
- National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, Guangdong, China.
| |
Collapse
|
10
|
Rosalbino F, Delsante S, Borzone G, Scavino G. Influence of noble metals alloying additions on the corrosion behaviour of titanium in a fluoride-containing environment. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1129-1137. [PMID: 22382735 DOI: 10.1007/s10856-012-4591-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 02/13/2012] [Indexed: 05/31/2023]
Abstract
Titanium alloys exhibit excellent corrosion resistance in most aqueous media due to the formation of a stable oxide film, and some of these alloys (particularly Ti-6Al-7Nb) have been chosen for surgical and odontological implants for their resistance and biocompatibility. Treatment with fluorides (F(-)) is known to be the main method for preventing plaque formation and dental caries. Toothpastes, mouthwashes, and prophylactic gels can contain from 200 to 20,000 ppm F(-) and can affect the corrosion behaviour of titanium alloy devices present in the oral cavity. In this work, the electrochemical corrosion behaviour of Ti-1M alloys (M = Ag, Au, Pd, Pt) was assessed in artificial saliva of pH = 3.0 containing 910 ppm F(-) (0.05 M NaF) through open circuit potential, E(OC), and electrochemical impedance spectroscopy (EIS) measurements. The corrosion behaviour of the Ti-6Al-7Nb commercial alloy was also evaluated for comparison. E (OC) measurements show an active behaviour for all the titanium alloys in fluoridated acidified saliva due to the presence of significant concentrations of HF and HF(2) (-) species that dissolve the spontaneous air-formed oxide film giving rise to surface activation. However, an increase in stability of the passive oxide layer and consequently a decrease in surface activation is observed for the Ti-1M alloys. This behaviour is confirmed by EIS measurements. In fact, the Ti-6Al-7Nb alloy exhibits lower impedance values as compared with Ti-1M alloys, the highest values being measured for the Ti-1Au alloy. The experimental results show that the corrosion resistance of the studied Ti-1M alloys is similar to or better than that of Ti-6Al-7Nb alloy currently used as biomaterial, suggesting their potential for dental applications.
Collapse
Affiliation(s)
- F Rosalbino
- Dipartimento di Scienza dei Materiali e Ingegneria Chimica (DICHI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
| | | | | | | |
Collapse
|
11
|
Comparative corrosion study of Ti-Ta alloys for dental applications. Acta Biomater 2009; 5:3625-39. [PMID: 19508903 DOI: 10.1016/j.actbio.2009.05.037] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 04/27/2009] [Accepted: 05/14/2009] [Indexed: 11/24/2022]
Abstract
Besides other important material features, the corrosion parameters and corrosion products are responsible for limiting the biocompatibility of metallic materials, and can produce undesirable reactions in implant-adjacent and/or more distant tissues. Titanium and some of its alloys are known as being the most biocompatible metallic materials due to their high strength, low modulus, high corrosion resistance in biological media, etc. More recently, Ti-Ta alloys have been developed, and these are expected to become more promising candidates for biomedical and dental applications than commercially pure Ti, Ti-6Al-4V or Ti-6Al-7Nb alloy. The corrosion behavior of the studied Ti-Ta alloys with Ta contents of 30, 40, 50 and 60 wt.% together with the currently used Ti-6Al-7Nb alloy were investigated for dental applications. All alloys were tested by open-circuit potential measurement, linear polarization, potentiodynamic polarization, coulometric zone analysis and electrochemical impedance spectroscopy performed in artificial saliva with different pH, acid lactic and fluoride contents. The passive behavior for all the titanium alloys is observed for artificial saliva, acidified saliva (9.8 gl(-1) lactic acid, pH 2.5) and for fluoridated saliva (1.0 gl(-1) F(-), pH 8). A decrease in corrosion resistance and less protective passive oxide films are observed for all titanium alloys in fluoridated acidified saliva (9.8 gl(-1) lactic acid, 1.0 gl(-1) F(-), pH 2.5) in regard to other electrochemical media used within this work. It is worthy of note that the most important decrease was found for Ti-6Al-7Nb alloy. These conclusions are confirmed by all the electrochemical tests undertaken. However, the results confirm that the corrosion resistance of the studied Ti-Ta alloys in all saliva is better or similar to that of Ti-6Al-7Nb alloy, suggesting that the Ti-Ta alloys have potential for dental applications.
Collapse
|