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Galvanic corrosion behavior of implant suprastructure dental alloys

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Abstract

The purpose of this study was to evaluate and compare in vitro, the galvanic corrosion behavior of Co-Cr alloys (R2000, R800), Ni-Cr (RCS), silver-palladium (Jelstar), Gold (Pontallor-4) and Ternary Ti (experimental Ter Ti) when coupled with endosseous Ti implant abutment material. Amalgam alloy and commercially pure Ti cylinders (SSTi) were coupled with endosseous Ti implants as negative and positive controls, respectively. An EG&G Model 263 Scanning Potentiostat was used for this purpose. Specimens were prepared and fresh artificial saliva was used as an electrolyte solution. The experiment run time was 24h for each couple. The common potential, galvanic current and current integration during the last 6h were recorded for each couple. The results showed that the best couples were Ti/Pontallor-4, Ti/Ter Ti, Ti/R800 and Ti/Jelstar. The least acceptable couples were Ti/amalgam, SSTi/SSTi and Ti/R2000, while the Ti/RCS couple showed unstable galvanic corrosion behavior. It is concluded that the following alloys can be used as suprastructure alloys with Ti implants: Pontallor-4, R800, Jelstar and Ter Ti. Although Ter Ti alloy is an experimental alloy, it showed good results, but cannot be used in the clinical field unless extensive investigations are carried out. The SSTi/SSTi couple showed unexpected galvanic corrosion behavior which needs further investigation.
... [1][2][3] The clinical performance of dental alloys is affected by a variety of factors related to the alloy microstructure, increases in grain size, casting defects, recasting, conditions in the oral environment, galvanic interference from other metals, pH value of the environment, contact with tissue, elements in the composition of the dental alloy, and element loss during the casting process. [4][5][6] Elements such as Ni, Co, Cu, and Fe are subjected to loss during the casting process as a result of evaporation and oxidation, and the release of Ni, Cr, Co, and Fe ions increases with the amount of the surplus alloy added to the new alloy. 5 Changes in the electrochemical balance among ions due to factors including dental plaque, pH, and temperature changes related to food and drink also increase the release of metal ions. ...
... Two types of electrochemical techniques are available: AAS, which involves immersion testing with the analytic determination of the quantity of released metal ions, and inductively coupled plasma spectroscopy, which involves potentiodynamic and potentiostatic polarization measurements to evaluate corrosion behavior. 4,24 Natural saliva is a complex system with numerous constituents and variables according to the time of day. Thus, exact duplication is impossible. ...
... Thus, exact duplication is impossible. 4 The current study is limited in that it does not accurately simulate intraoral conditions and only 1 type of dental casting alloy and composition are investigated. Predicting the clinical behavior of an alloy from in vitro studies is difficult because changes in the quantity and quality of saliva, diet, oral hygiene, polishing of the alloy, or brushing with toothpaste can all influence element release. ...
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Statement of problem. The addition of previously cast alloy to new alloy for economic reasons may increase the release of elements. Purpose. The purpose of this study was to analyze the effects of the immersion period, immersion media, and addition of previously cast alloy to new alloy on the release of elements. Material and method. Disk-shaped specimens were prepared from a Ni-Cr alloy (Ni: 61 wt%, Cr: 26 wt%, Mo: 11 wt%, Si: 1.5 wt%, Fe, Ce, Al, and Co <1 wt%) (Remanium CS; Dentaurum) with new alloy (group N) and 50% new/50% recast alloy (group R). After the immersion of the specimens in both NaCl (pH 4) and artificial saliva (pH 6.7) for 3, 7, 14, 30, and 60 days, the release of ions was determined by using atomic absorption spectrometry. Data were analyzed with a 3-way ANOVA (a¼.001).
... Metal elements in the body remain in contact with the bodily fluids, which are electrolytic in character, and so they undergo corrosion. This process causes, on the one hand, their destruction, and on the other hand, release of corrosion products and metal ions into the surrounding tissue, which, in many cases, has a very disadvantageous effect on the body [1][2][3][4][5][6][7]. Metal elements made of non-precious metals are at present quite broadly used in dental prosthetics and orthodontics. ...
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Background: Investigating the general corrosion resistance of Ti(C,N) type coatings on a prosthetic nickel alloy in the aspect of their use as protective coatings on prosthetic and orthodontic elements. Methods: Five groups of Ni-Cr alloy samples covered with Ti(C,N) type coatings differing in their carbon and nitrogen contents were used for the tests. The reference group included alloy samples without coatings. The samples were held for 105 days (2520 h) in salt spray chambers and examined by means of the NSS (neutral salt spray) and SWAAT (sea water acetic acid test) tests. After the periods of 14, 28, 81 and 105 days, the samples were removed and weighed, and their weight losses were determined. Results: In the case of each type of Ti(C,N) coating, the mass loss was lower than the mass loss of a sample without a coating, which makes it possible to state that coatings improve the corrosion resistance. No significant differences in the resistance were observed between the particular coatings. The corrosion rate of the examined coatings is close to parabolic. Conclusions: Ti(C,N) type coatings improve the resistance of a prosthetic Ni-Cr alloy and can be used as protective coatings for prosthetic and orthodontic elements.
... Taher and Jabab [22] report that the chemical composition of the alloy, porosity, and polishing of the sample influence the corrosion resistance and affect the galvanic behavior of the materials. In keeping with these aforementioned results, it is possible to understand why titanium has had two distinct behaviors. ...
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Dental implant systems are composed of an implant, prosthetic components, and a crown. Since the implants are made of commercially pure Ti (cp Ti) and prosthetic components are often made of Ti and CoCrMo alloys, a galvanic couple between these two devices may lead to galvanic corrosion, ions release, and even loss of the implant. This study aimed to investigate the corrosion resistance and measure the galvanic potential between cp Ti alloys (annealed microstructured cp Ti G4 and cold-worked nanostructured cp Ti G4) and a CoCrMo alloy. The corrosion resistance has been characterized by measuring the open circuit potential, the potentiodynamic polarization, the potentiostatic polarization, and the zero-resistance current. The cp Ti has been tested before and after a surface acid treatment. The samples’ surfaces have been examined by scanning electron microscopy, and their surface roughness has been measured by a 3D optical profilometer. The polarization results showed that the CoCrMo alloy showed lower corrosion resistance than cp Ti. The surface acid treatment improves dental implant corrosion resistance. The galvanic analysis showed that the cp Ti without surface treatment behaved as an anode and after the acid treatment has a cathodic behavior in relation to the CrCoMo alloy. The highest value of galvanic current was cp TiG4 acid etched in contact with CoCrMo, in pH 2 solution. The galvanic couple with the lowest current has been the nanostructured cp Ti in contact with CoCrMo alloy.
... This is due to the easy manufacturing procedure, availability, low price and last but certainly not least, corrosion resistance of these metallic biomaterials. Nickel-based alloys containing chromium develop a thin protective oxide layer on their surfaces, although they show unstable galvanic corrosion (Gushcha et al., 2019;Taher and Al Jabab, 2003). Certainly, the body environment is complex and presents difficult challenges regarding corrosion control that may be experienced by metallic biomaterials (Eliaz, 2019). ...
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Purpose-This paper aims to analyze the corrosion behavior in Ringer solution of six commercially used Ni-based alloys that are present and commonly used as metallic biomaterials. Design/methodology/approach-The specimens were received in the form of cylindrical ingots and were cut to get five samples of each brand with a cylindrical shape of 2 mm height to conduct the study. In this scientific research, the following techniques were used: open circuit potential, potentiodynamic polarization studies, and electrochemical impedance spectroscopy. Findings-The study findings revealed the passivation tendency of the different specimens. Additionally, when the materials were compared, it was discovered that the decisive factor for high corrosion resistance was the chromium concentration. However, with similar chromium content, the stronger concentration in molybdenum increased the resistance. According to the results obtained in this investigation, the biological safety of the dental materials studied in Ringer solution was considered very high for specimens 1 and 2, and adequate for the other samples. Originality/value-Metal alloys used as biomaterials in contact with the human body should be deeply investigated to make sure they are biocompatible and do not cause any harm. The corrosion resistance of an alloy is the most important characteristic for its biological safety, as all problems arise because of the corrosion process. There is scarce investigation in these Ni-based dental biomaterials, and none found in these commercially used dental materials in Ringer solution.
... [11] Chewing ability and speech or phonation was graded "good" at all the specified time intervals in all patients. Contrary to the findings of Taher and Jabab, [12,13] who discussed about galvanic corrosion of implant, in our study, patients, whether of single implant or multiple implants with long span prosthesis, did not report metallic taste at any of the time intervals. ...
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Aim: The aim of the present study was to evaluate clinically, radiographically, and functionally the outcomes of immediately loaded basal implants when placed in patients with compromised bone/alveolar ridges. Materials and methods: A total of 18 systemically healthy (9 male and 9 female) subjects with compromised bone with poor quantity or quality were included in the study. A total number of 57 implants was placed, out of which 26 implants were placed in maxilla and 31 implants in mandible. There were 6 patients in which single implants were placed and in rest of the 12 patients, multiple implants were placed, out of which full mouth rehabilitation was done in one patient. In 10 patients, implants were placed immediately in fresh extraction socket and in 7 patients, implants were placed in healed edentulous site. In all the patients, loading was done immediately within 72 h of implant placement. All patients were evaluated for primary and secondary stability, pain, periimplant bone levels using IOPA with grid and CBCT, bleeding, suppuration, sulcular bleeding index, prosthetic complications, and patient satisfaction at specified time intervals. Result: All the values obtained during the study were expressed in the form of mean, standard deviation, and standard error of the mean. The parameters were compared between groups using Paired t-test for intragroup comparison at a similar time, i.e., baseline, 1 month, and 3 months. The data collected was comprehensively analyzed using SPSS software. All implants were successful, with no incidence of infection, nil mobility at the end of the study period of 6 months. Conclusion: Thus, it can be concluded from the present study, that Basal implants can play a vital role in the rehabilitation of patients, where compromised quality and/or quantity of bone is present and additional augmentation procedures would be required for the placement of conventional root form implants.
... To avoid the limitations of the mixed potential theory, specially obtained when studying passive materials, the galvanic effect was directly measured through a zero-resistance-ammeter (ZRA) [1,10,16,17,20,21]. Some other authors also tested the system superstructure/implant [18,22,23] and the measure of the corrosion damage was directly measured by quantifying the metal ion release after immersion tests of superstructures and implants couples by different analytical techniques such as the Inductively Coupled Plasma-Atomic Emission Spectrometry [23]. ...
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The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry) in artificial saliva (AS), with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys.
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Objectives This study aimed to evaluate fatigue resistance of cast-on implant abutment using three alloys. Materials and Methods Forty specimens of implant-supported crowns were prepared; Group 1 (TA) stock titanium abutments, Group 2 (GS) abutment cast with 40% gold alloy, Group 3 (GP) abutment cast with palladium alloy, and Group 4 (CN) abutment cast with nickel–chromium alloy. Specimens were cyclic loaded at 20 Hz, starting from 200 N (5,000 cycles), followed by stepwise loading of 400, 600, 800, 1,000, 1,200, 1,400, 1,600, and 1,800 N (30,000 cycles/step). Specimens were loaded until failure or reached 245,000 cycles. Statistical Analysis The withstand cycles were analyzed using one-way analysis of variance and Weibull survival analysis. Fracture surfaces were examined using scanning electron microscopy. Results The results of withstand cycles were TA (189,883 ± 22,734), GS (195,028 ± 22,371), GP (187,662 ± 22,555), and CN (200,350 ± 30,851). The statistical analysis showed no significant difference between the groups (p = 0.673). Conclusion Although CN has higher Weibull characteristic strength which means greater durability, its lower Weibull modulus demonstrated less structural reliability. Consistent failures at implant fixture level were also found in CN group.
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Purpose This paper aims to analyze the corrosion behavior in Ringer solution of six commercially used Ni-based alloys that are present and commonly used as metallic biomaterials. Design/methodology/approach The specimens were received in the form of cylindrical ingots and were cut to get five samples of each brand with a cylindrical shape of 2 mm height to conduct the study. In this scientific research, the following techniques were used: open circuit potential, potentiodynamic polarization studies, and electrochemical impedance spectroscopy. Findings The study findings revealed the passivation tendency of the different specimens. Additionally, when the materials were compared, it was discovered that the decisive factor for high corrosion resistance was the chromium concentration. However, with similar chromium content, the stronger concentration in molybdenum increased the resistance. According to the results obtained in this investigation, the biological safety of the dental materials studied in Ringer solution was considered very high for specimens 1 and 2, and adequate for the other samples. Originality/value Metal alloys used as biomaterials in contact with the human body should be deeply investigated to make sure they are biocompatible and do not cause any harm. The corrosion resistance of an alloy is the most important characteristic for its biological safety, as all problems arise because of the corrosion process. There is scarce investigation in these Ni-based dental biomaterials, and none found in these commercially used dental materials in Ringer solution.
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Metallic materials utilized for the construction of intra-oral and implant dental restorations include a wide range of relatively pure metals and multicomponent alloys. Basic corrosion and biodegradation properties of these alloys have been studied by both in vitro and in vivo techniques. These property characteristics have been shown to be dependent on composition and metallurgical state, combinations within a construct, surface conditions, mechanical aspects of function, and the local and systemic host environment. The susceptibility of these metallic materials to various forms of biodegradation will be presented, with emphasis on corrosion.
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Sixty-six consecutive patients treated at the Prosthodontic Clinic in Uppsala, Sweden, received implant-supported fixed prostheses of the Brånemark type. The prosthesis frameworks were made of cobalt-chromium alloys. Different techniques for attaching the gold cylinders to the frameworks were used. Mechanical attachment with autopolymerizing polymethyl methacrylate resin (PMMA), partial soldering combined with PMMA attachment, and soldering only were used. No abnormal tissue reactions were seen. Radiographic examination of the implants was performed at the time of prosthesis placement and at the 1- and 3-year follow-up visits. A few cases of minor bone loss were detected but not related to the materials used in the superstructures.
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Sixty-six consecutive patients treated at the Prosthodontic Clinic in Uppsala, Sweden, received implant-supported fixed prostheses of the Brånemark type. The prosthesis frameworks were made of cobalt-chromium alloys. Different techniques for attaching the gold cylinders to the frameworks were used. Mechanical attachment with self-curing polymethyl methacrylate (PMMA), partial soldering combined with PMMA attachment, and soldering only were used. No abnormal tissue reactions were seen. Radiographic examination of the fixtures was performed at the time of prosthesis placement and at the 1- and 3-year follow-ups. A few cases of minor bone loss were detected but not related to the materials used in the superstructures.
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The corrosion of two materials for implant supraconstructions, a carbon fiber/PMMA composite and a silver-palladium alloy, was investigated in vitro, the materials being galvanically coupled to a titanium implant. Corrosion current and pH of the electrolyte were monitored, and corrosion products were identified by powder X-ray diffraction. The carbon composite and the silver-palladium per se did not corrode, whereas a silver-palladium specimen brazed with the recommended brazing alloy corroded unmistakably, yielding copper-containing corrosion products. The action of local corrosion cells around the brazed joint is considered, and it is concluded that the two materials seem well suited for implant supraconstructions, provided that brazing the silver-palladium can be avoided. Considering the clinical relevance of the experimental model used, it is concluded that the model is likely to predict a lower corrosion susceptibility than the one found in vivo.
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Corrosion reactions around titanium, usually considered biologically inert, might be provoked by coupling it galvanically with more corrodible dental alloys. Experiments in vitro simulating the conditions of a titanium dental implant or root canal post coupled to an amalgam filling, demonstrated corrosion current densities up to 31 microA/cm2, anodic pH values around the amalgam down to 2, and cathodic pH values around the titanium up to 10. The amounts of tin released by the enhanced corrosion of amalgam might contribute measurably to the daily intake of this element; the corrosion current generated reached values known to cause taste sensations. If the buffer systems of adjacent tissues in vivo are not able to cope with the high pH generated around the titanium, local tissue damage may ensue; this relationship is liable to be overlooked, as it leaves no evidence in the form of corrosion products.