Evaluation of effect of galvanic corrosion between nickel-chromium metal and titanium on ion release and cell toxicity

PURPOSE: The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS: It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens (10 x 10 x 1.5 mm) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3, Tilite, Bella bond plus) commonly used for metal ceramic restorations. The specimens were divided into 6 groups according to the composition of Ni-Cr alloy and contact with titanium. The experimental groups were in direct contact with titanium and the control groups were not. After the samples were immersed in the culture medium - Dulbecco's modified Eagle's medium[DMEM] for 48 hours, the released metal ions were detected using inductively coupled plasma mass spectrometer (ICP-MS) and analyzed by the Kruskal-Wallis and Mann-Whitney test (P<.05). Mouse L-929 fibroblast cells were used for cell toxicity evaluation. The cell toxicity of specimens was measured by the 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyltetrazolium bromide (MTT) test. Results of MTT assay were statistically analyzed by the two-way ANOVA test (P<.05). Post-hoc multiple comparisons were conducted using Tukey's tests. RESULTS: The amount of metal ions released by galvanic corrosion due to contact between the base metal alloy and titanium was increased in all of the specimens. In the cytotoxicity test, the two-way ANOVA showed a significant effect of the alloy type and galvanic corrosion for cytotoxicity (P<.001). The relative cell growth rate (RGR) was decreased further on the groups in contact with titanium (P<.05). CONCLUSION: The release of metal ions was increased by galvanic corrosion due to contact between base metal and titanium, and it can cause adverse effects on the tissue around the implant by inducing cytotoxicity.

Evaluation of effect of galvanic corrosion between nickel-chromium metal and titanium on ion release and cell toxicity

PURPOSE: The purpose of this study was to evaluate cell toxicity due to ion release caused by galvanic corrosion as a result of contact between base metal and titanium. MATERIALS AND METHODS: It was hypothesized that Nickel (Ni)-Chromium (Cr) alloys with different compositions possess different corrosion resistances when contacted with titanium abutment, and therefore in this study, specimens (10 x 10 x 1.5 mm) were fabricated using commercial pure titanium and 3 different types of Ni-Cr alloys (T3, Tilite, Bella bond plus) commonly used for metal ceramic restorations. The specimens were divided into 6 groups according to the composition of Ni-Cr alloy and contact with titanium. The experimental groups were in direct contact with titanium and the control groups were not. After the samples were immersed in the culture medium - Dulbecco's modified Eagle's medium[DMEM] for 48 hours, the released metal ions were detected using inductively coupled plasma mass spectrometer (ICP-MS) and analyzed by the Kruskal-Wallis and Mann-Whitney test (P<.05). Mouse L-929 fibroblast cells were used for cell toxicity evaluation. The cell toxicity of specimens was measured by the 3-{4,5-dimethylthiazol-2yl}-2,5-diphenyltetrazolium bromide (MTT) test. Results of MTT assay were statistically analyzed by the two-way ANOVA test (P<.05). Post-hoc multiple comparisons were conducted using Tukey's tests. RESULTS: The amount of metal ions released by galvanic corrosion due to contact between the base metal alloy and titanium was increased in all of the specimens. In the cytotoxicity test, the two-way ANOVA showed a significant effect of the alloy type and galvanic corrosion for cytotoxicity (P<.001). The relative cell growth rate (RGR) was decreased further on the groups in contact with titanium (P<.05). CONCLUSION: The release of metal ions was increased by galvanic corrosion due to contact between base metal and titanium, and it can cause adverse effects on the tissue around the implant by inducing cytotoxicity.

Retrieval analysis of different orthodontic brackets: the applicability of electron microprobe techniques for determining material heterogeneities and corrosive potential

OBJECTIVE: The objective of this study was to investigate the applicability of micro-analytical methods with high spatial resolution to the characterization of the composition and corrosion behavior of two bracket systems. MATERIAL AND METHODS: The surfaces of six nickel-free brackets and six nickel-containing brackets were examined for signs of corrosion and qualitative surface analysis using an electron probe microanalyzer (EPMA), prior to bonding to patient's tooth surfaces and four months after clinical use. The surfaces were characterized qualitatively by secondary electron (SE) images and back scattered electron (BSE) images in both compositional and topographical mode. Qualitative and quantitative wavelength-dispersive analyses were performed for different elements, and by utilizing qualitative analysis the relative concentration of selected elements was mapped two-dimensionally. The absolute concentration of the elements was determined in specially prepared brackets by quantitative analysis using pure element standards for calibration and calculating correction-factors (ZAF). RESULTS: Clear differences were observed between the different bracket types. The nickel-containing stainless steel brackets consist of two separate pieces joined by a brazing alloy. Compositional analysis revealed two different alloy compositions, and reaction zones on both sides of the brazing alloy. The nickel-free bracket was a single piece with only slight variation in element concentration, but had a significantly rougher surface. After clinical use, no corrosive phenomena were detectable with the methods applied. Traces of intraoral wear at the contact areas between the bracket slot and the arch wire were verified. CONCLUSION: Electron probe microanalysis is a valuable tool for the characterization of element distribution and quantitative analysis for corrosion studies.

Surface roughness changes caused by the galvanic corrosion between a titanium abutment and base metal alloy / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the level of electro-chemical corrosion and surface roughness change for the cases of Ti abutment connected to restoration made of base metal alloys. MATERIALS AND METHODS: It was hypothesized that Ni-Cr alloys in different compositions possess different corrosion resistances, and thus the specimens (13x13x1.5 mm) in this study were fabricated with 3 different types of metal alloys, commonly used for metal ceramic restorations. The electrochemical characteristics were evaluated with potentiostat (Parstat 2273A) and the level of surface roughness change was observed with surface roughness tester. Paired t-test was used to compare mean average surface roughness (Ra) changes of each specimen group. RESULTS: All specimens made of nickel-chromium based alloys, average surface roughness was increased significantly (P < .05). Among them, the Ni-Cr-Be alloy (0.016 +/- 0.007 microm) had the largest change of roughness followed by Ni-Cr (0.012 +/- 0.003 microm) and Ni-Cr-Ti (0.012 +/- 0.002 microm) alloy. There was no significant changes in surface roughness between each metal alloys after corrosion. CONCLUSION: In the case of galvanic couples of Ti in contact with all specimens made of nickel-chromium based alloys, average surface roughness was increased.

The electrochemical properties of four dental casting suprastructure alloys coupled with titanium implants

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.

Measurement of galvanic current of dental common restorative alloys and clinical significance / 吉林大学学报(医学版)

Objective To measure the magnitude of galvanic currents produced by different occluding metallic contact.Methods The circuits of instantly different metallic contact were simulated in artificial saliva,and electrical potential of every couple and 15 currents of instant contact were measured.To simulate night sleep,after 8 h soaking,15 currents were obtained in addition.Results During early soaking,gold/Co-Cr alloy produced the highest current(6.17 ?A),while there were significant differences in currents between gold/zinc-free amalgam,gold /zinc-containing amalgam and other couples(P0.05),and the current value was low all the time.Potential of zinc-containing amalgam was more negative than other alloys,and it was always under anodic behavior during the experiment and was corrupted acceleratedly.Conclusion Couples of gold/titatium,gold/zinc-containing amalgam,zinc-free/zinc-containing amalgam appearing in oral will do harm to the patients′health,while Co-Cr/zinc-free amalgam can coexist in oral.Corrosion behavior of amalgam is affected by different contents of zinc.

The study of galvanic corrosion between soft magnetic alloy and 4 types of dental alloys in common dental application / 实用口腔医学杂志

0.05).Conclusion: Feasibility of galvanic corrosion between Fe-16Cr-2Mo soft magnetic alloy and dental alloys used in clinic application can be omitted.

Effect of pH on intermittent galvanic current of commonly used dental restorative alloys / 实用口腔医学杂志

Objective:To study the effect of pH on intermittent galvanic current of commonly used dental restorative alloys.Methods:The circuits of instantly different metallic contact were simulated in artificial saliva with 3 different pH values(5.6,6.8 and 7.6),and electrical potential of every couple and 15 currents of instant contact were measured.Results:The current of gold/pure titanium was higher than that of the other couples(P

Galvanic corrosion of soft magnetic alloy and 4 types of dental alloys in common use / 实用口腔医学杂志

Objective: To study the property of galvanic corrosion of soft magnetic alloy and 4 kinds of dental alloys in simulated oral environment. Methods: 6 samples of Ni Cr, TA 2, Ti75 and 30 of Fe 16Cr 2Mo in the size of d 15 mm?3 mm were prepared and put into artificial saliva. An electrochemical method was used in the measurement of electric potential of corrosion (Ecorr), potential dynamic polarization and galvanic current density of different galvanic couple, the anticorrosive property of four galvanic couples was analyzed statistically. Results: The ecorr value(mV) of Ti75, TA 2, Co Cr,Fe 16Cr 2Mo and Ni Cr was -138.31?2.89, -150.35?1.04, -186.21?3.79, -218.35?0.84 and -240.49?1.73 respectively ( P

Galvanic corrosion behavior of dental amalgam coupled to three types of dental alloys in common use / 重庆医科大学学报

Objective: The galvanic corrosion behavior of dental amalgam coupled to three types of dental alloys in common use(pure Ti?Ni-Cr alloy and Co-Cr alloy),was investigated in artificial saliva.Methods: An electrochemical method was used in the measurement of corrosion potential(Ecorr)?polarization resistance(Rp) and corrosion current density(Icorr) of four types of alloys,and current density of three galvanic couples.These electrochemical parameters were analyzed statistically.Results: The corrosion potential,polarization resistance and corrosion current density,respectively,were statistically different among the different alloys(P