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Electrochemical behavior of three CP titanium dental implants in artificial saliva
Kadowaki, Norma Terumi;Martinez, Gustavo Aristides Santana;Robin, Alain;
Materials Research , 2009, DOI: 10.1590/S1516-14392009000300018
Abstract: the electrochemical behavior of three titanium dental implants purchased on the brazilian market was evaluated in artificial saliva using open-circuit potential measurements, electrochemical impedance spectroscopy and potentiodynamic polarization. the three implants are passive in this medium but their corrosion resistance and the stability of their passive oxide films are quite different. although the three implants were made of commercially pure grade titanium, their corrosion current densities and passive current densities were shown to differ from one to two orders of magnitude.
The electrochemical properties of four dental casting suprastructure alloys coupled with titanium implants
Tuna, Suleyman Hakan;Pekmez, Nuran Ozcicek;Keyf, Filiz;Canli, Fulya;
Journal of Applied Oral Science , 2009, DOI: 10.1590/S1678-77572009000500022
Abstract: objectives: as the choice of suprastructure alloy to be combined with titanium for the oral cavity is still a much debated issue, the aim of this study was to investigate the electrochemical interaction of the suprastructure/implant couples under the determined experiment conditions. material and methods: the potentiodynamic polarization curves and open-circuit potentials (ocp) of four ucla type suprastructures coupled with straight swiss plus implant fixtures were taken in afnor type artificial saliva solution at 37°c. the concentration of ions leached into artificial saliva solutions was estimated with icp-ms. sem images of the margins of suprastructure/implant couples were obtained before and after the electrochemical tests. results: the ocp value of titanium became passive at the most negative potential. the lowest difference between the initial and constant ocp value was exhibited by the au based suprastructure. suprastructures made greater contributions to the potentiodynamic polarization curves of the implant/suprastructure couples. according to the icp-ms results, pd based and au based couples dissolved less than co-ni based and co-cr based couples. conclusions: within the conditions this study, it may be concluded that the titanium implant forms a stable passive oxide layer in artificial saliva exposed to open air and does not affect the corrosion properties of the suprastructures. pd based and au based couples have been found to be more corrosion-resistant than base alloy couples.
Electrochemical Evaluation of Wrought Titanium -15 Molybdenum Alloy for Dental Implant Applications in Phosphate Buffer Saline
Bhola,Rahul; Bhola,Shaily M.; Mishra,Brajendra; Olson,David L.;
Portugaliae Electrochimica Acta , 2010,
Abstract: ti-15mo alloy has been evaluated for its electrochemical behavior in phosphate buffer saline solution at the physiological temperature of 37 oc. a two time constant model of a duplex oxide layer has been used to assess the corrosion behavior of the ti-15mo alloy-solution interface using electrochemical impedance spectroscopy (eis). interfacial characteristics of the inner barrier layer and the outer porous layer have been studied to understand the role of the alloy as an implant. ti-15mo alloy shows a very high barrier layer resistance and a tendency to resist localized corrosion.
Electrochemical Evaluation of Wrought Titanium -15 Molybdenum Alloy for Dental Implant Applications in Phosphate Buffer Saline  [cached]
Rahul Bhola,Shaily M. Bhola,Brajendra Mishra,David L. Olson
Portugaliae Electrochimica Acta , 2010,
Abstract: Ti-15Mo alloy has been evaluated for its electrochemical behavior in phosphate buffer saline solution at the physiological temperature of 37 oC. A two time constant model of a duplex oxide layer has been used to assess the corrosion behavior of the Ti-15Mo alloy-solution interface using electrochemical impedance spectroscopy (EIS). Interfacial characteristics of the inner barrier layer and the outer porous layer have been studied to understand the role of the alloy as an implant. Ti-15Mo alloy shows a very high barrier layer resistance and a tendency to resist localized corrosion.
Electrochemical Tests to Evaluate the Stability of the Anodic Films on Dental Implants  [PDF]
C. E. B. Marino,L. H. Mascaro
International Journal of Electrochemistry , 2011, DOI: 10.4061/2011/574502
Abstract: The stability of anodic films potentiodynamically grown on titanium, titanium-grade 2, and Ti6Al4V alloy was studied in a simulated physiological electrolyte, up to 8.0?V, and at room temperature to determine the corrosion resistance levels of dental implants. In PBS (phosphate buffer saline) solution, thin titanium oxide films protect the surface of the Ti6%Al4%V alloy up to 6.0?V, pure Ti up to 8.0?V, and Ti-grade 2 up to 1.5?V. At more positive potentials, localized corrosion starts to occur possibly due to the alloy elements (Ti6Al4V-V and Al) and variable levels of interstitials (Ti-grade 2:?C, N, and Fe, mainly). When the biomaterials were submitted to open-circuit conditions, in artificial saliva, the worst corrosion resistance was observed in dental implant (Ti-grade 2), according to the open-circuit potential values and reconstruction rate analysis of these oxide films. The XPS spectra revealed TiO2 oxide as the main phase in the barrier oxide film coating the dental implant. 1. Introduction The use of titanium as a material for surgical purposes began around the 1960s. For this purpose, this material must not cause any adverse biological reaction in the body, and it must also be stable and retain its functional properties. Due to its attractive mechanical and chemical characteristics and its property of “biofixation” with the periprosthetic tissue, titanium is established as one of the major materials used for manufacturing orthopedic implants [1]. The excellent corrosion resistance of titanium and its alloys results from the formation of very stable, continuous, highly adherent, and protective oxide films on metal surfaces. Because titanium itself is highly reactive and has extremely high affinity for oxygen, these beneficial surface oxide films form spontaneously and instantly when fresh metal surfaces are exposed to air. The nature, composition, and thickness of the protective surface oxides on titanium alloys depend on environment conditions. Titanium is normally covered with a thin oxide film, which largely determines the surface properties of an implant [1]. The high corrosion resistance of titanium is due to the formation of these protective oxide films (thickness 1 to 4?nm) [2], but body fluids contain chloride ions that can induce a breakdown of passive films on prostheses [3, 4]. Corrosion and surface film dissolution are two mechanisms for introducing additional ions in the human body. Extensive release of metal ions from prosthesis can result in adverse biological reactions and can lead to mechanical failure of the device [5]. The
Fatigue behaviour of titanium dental endosseous implants  [PDF]
Ferdinando Felli,Daniela Pilone,Alessandro Scicutelli
Frattura ed Integrità Strutturale , 2011,
Abstract: In this work two different titanium dental implants are analyzed in order to evaluate their mechanical strength. An ad-hoc designed experimental apparatus is prepared to test against fatigue these implants in a way that approximates as much as possible the actual stresses occurring during mastication motion. The results of these endurance tests are summarized in the form of Wohler-type diagrams showing the duration of a specific implant for different applied loads. These plots show a fatigue limit below which the implants could resist indefinitely. Other aspects of this research concern the influence of a potentially corrosive medium and the analysis of the deformation and failure of the specimens. During fatigue cycling, the titanium implants do not seem to be affected by a more aggressive environment, such as a saline solution. The analysis of the broken specimen allowed the crack initiation sites and the type of fracture propagation to be investigated in depth. In all the considered implants fatigue cracks were seen to initiate preferentially from sites in which the tensile stress concentration is the highest. The results of a finite element analysis performed on one of the specimens is in good agreement with the failure mode observed after the tests. The SEM fracture surface analysis shows a clear similarity between the fracture mode of the tested implants and of the actual implants broken after a certain operating period.
Structure and properties of Titanium for dental implants  [PDF]
M. Greger,M. ?erny,L. Kander,J. Kliber
Metalurgija , 2009,
Abstract: This paper describes manufacture of nano-structural titanium, its structure and properties. Nano-titanium has higher specific strength properties than ordinary (coarse-grained) titanium. Nano-titanium was produced by the equal-channel angular pressing (ETAP) process. The research it self was focused on physical base of strengthening and softening processes and developments occurring at the grain boundaries during the ECAP process at half-hot temperature. Strength of nano-titanium varies around 960 MPa, grain size around 300 nm.
A Review of Titanium Zirconium (TiZr) Alloys for Use in Endosseous Dental Implants  [PDF]
H. Michelle Grandin,Simon Berner,Michel Dard
Materials , 2012, DOI: 10.3390/ma5081348
Abstract: Dental implants made from binary titanium-zirconium (TiZr) alloys have shown promise as a high strength, yet biocompatible alternative to pure titanium, particularly for applications requiring small diameter implants. The aim of this review is to summarize existing literature reporting on the use of binary TiZr alloys for endosseous dental implant applications as tested in vitro, in animals and clinically. And furthermore to show that TiZr is “at least as good as” pure titanium in terms of biocompatibility and osseointergration. From the twelve papers that met the inclusion criteria, the current literature confirms that TiZr alloys produce small diameter implants with a strength up to 40% higher than conventional, cold-worked, grade IV titanium implants, and with a corrosion resistance and biocompatibility that is at least as good as pure titanium. The surface structure of TiZr is compatible with established surface treatments proven to aid in the osseointegration of titanium implants. Furthermore, binary TiZr alloys have been shown to achieve good osseointegration and high success rates both in animal and in clinical studies.
An overview of the corrosion aspect of dental implants (titanium and its alloys)  [cached]
Chaturvedi T
Indian Journal of Dental Research , 2009,
Abstract: Titanium and its alloys are used in dentistry for implants because of its unique combination of chemical, physical, and biological properties. They are used in dentistry in cast and wrought form. The long term presence of corrosion reaction products and ongoing corrosion lead to fractures of the alloy-abutment interface, abutment, or implant body. The combination of stress, corrosion, and bacteria contribute to implant failure. This article highlights a review of the various aspects of corrosion and biocompatibility of dental titanium implants as well as suprastructures. This knowledge will also be helpful in exploring possible research strategies for probing the biological properties of materials.
Electrochemical Disinfection of Dental Implants – a Proof of Concept  [PDF]
Dirk Mohn,Matthias Zehnder,Wendelin J. Stark,Thomas Imfeld
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0016157
Abstract: Peri-implantitis has gained significant clinical attention in recent years. This disease is an inflammatory reaction to microorganisms around dental implants. Due to the limited accessibility, non-invasive antimicrobial strategies are of high interest. An unexpected approach to implant disinfection may evolve from electrolysis. Given the electrical conductivity of titanium implants, alkalinity or active oxidants can be generated in body fluids. We investigated the use of dental titanium implants as electrodes for the local generation of disinfectants. Our hypothesis was that electrolysis can reduce viable counts of adhering bacteria, and that this reduction should be greater if active oxidative species are generated.
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