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Oral Surgery, Oral Medicine, Oral... Feb 2012
Topics: Cobalt; Crowns; Dental Alloys; Dermatitis, Allergic Contact; Humans; Male; Psoriasis
PubMed: 22669109
DOI: 10.1016/j.tripleo.2011.05.048 -
Dental Materials : Official Publication... May 2019Dental restorations made from alloys corrode during their service time. In cases of suspected toxic or allergic reactions to the corrosion products, the composition of...
UNLABELLED
Dental restorations made from alloys corrode during their service time. In cases of suspected toxic or allergic reactions to the corrosion products, the composition of the intraoral dental restorations has to be determined. The sample materials can be obtained intra-orally in a non-destructive manner using the chipping test. Metallic shavings are extracted with the aid of a dental stone and graphite carrier platelet, which is then transferred to an electron microscope for electro dispersive X-ray (EDX) analysis. The chipping test suffers from a rather complicated and error-prone procedure of obtaining and transferring the samples.
OBJECTIVE
The objective of the present study was the validation of a simplified method for non-destructive in-situ extraction of dental alloy samples, using a newly developed dental bur made from carbon fiber reinforced polyether ether ketone (PEEK), which at the same time serves as an electrically conductive sample carrier for EDX analysis.
METHODS
Fifteen burs for dental hand pieces were manufactured from carbon fiber reinforced PEEK, using two formulations. The burs were passed over precious and non-precious dental alloys with different rotation speeds. The alloy samples embedded in the burs were analyzed using EDX and compared to a control.
RESULTS
The burs manufactured from PEEK containing 30% short carbon fibers proved sufficiently robust for sample extraction even from the harder non-precious metals. The results of EDX analysis were in accordance with the control,no statistical significant differences, free of contamination, and were not affected by rotation speed,higher as 20%.
SIGNIFICANCE
The proposed method is valid, practical and constitutes an improvement over the traditional chipping test.
Topics: Corrosion; Dental Alloys; Dental High-Speed Equipment; Dental Materials; Ketones
PubMed: 30846373
DOI: 10.1016/j.dental.2019.02.009 -
Chemosphere Mar 2020To determine whether the potential effects on liver and kidney caused by dental alloys could be reduced or terminated by the removal of nickel-chromium (Ni-Cr) alloy,...
To determine whether the potential effects on liver and kidney caused by dental alloys could be reduced or terminated by the removal of nickel-chromium (Ni-Cr) alloy, cobalt-chromium (Co-Cr) alloy, and commercially pure titanium (CP-Ti), they were placed in the cheek pouches of Syrian hamsters according to ISO 10993-10. Then, the peak/plateau and end times of trace metals in the blood were determined with or without the removal of the dental alloys. Based on these time points, the trace metals and their effects on liver and kidney were examined. We found that trace metals released from these dental alloys and titanium were accumulated transiently in the blood, liver, and kidney but had no effect on the histopathology of the liver or kidney. Although the functions of the liver and kidney were compromised, the function of these tissues seemed to be clinically acceptable compared to those in control Syrian hamsters. In addition, the apoptotic effect on renal cells was terminated by removing the Ni-Cr and Co-Cr alloys, and that on hepatocytes was also eliminated by removing the Ni-Cr alloy. In contrast, the effect of the Co-Cr alloy on hepatocytes was temporary and recovered by itself. Taken together, Ni- and Co-based dental alloys and titanium have no effect on the histopathology or function of liver and kidney. Moreover, Ni-Cr and Co-Cr alloys induce transient trace metal accumulation and apoptotic effects in liver and kidney, which can be reduced or terminated by the removal of the alloys, while CP-Ti shows favorable biocompatibility.
Topics: Alloys; Chromium Alloys; Dental Alloys; Kidney; Liver; Materials Testing; Titanium
PubMed: 31726262
DOI: 10.1016/j.chemosphere.2019.125205 -
Dental Materials : Official Publication... Jul 2007The aim of the study is to investigate the stress-strain response of different dental materials, especially dental brittle materials, and compare them with enamel. (Comparative Study)
Comparative Study
OBJECTIVES
The aim of the study is to investigate the stress-strain response of different dental materials, especially dental brittle materials, and compare them with enamel.
METHODS
A nano-based indentation system (Ultra Micro-Indentation System, UMIS-2000, CSIRO, Australia) was used to determine the indentation stress-strain response of two kinds of dental ceramics (Cerec 2 Mark II and Vita VM9), one kind of dental alloy (Wiron 99) and healthy enamel. A spherical indenter was used to test the materials with nanometer and micro-Newton displacement and force resolution. Assuming the elastic modulus remained constant, a plot of contact pressure versus contact strain, H-a/R, of each material was obtained.
RESULTS
By comparing the H-a/R curve of the different materials with enamel, it can be concluded that only the metallic alloy, has similar stress-strain response as enamel. Dental ceramics showed much higher yield stress response than enamel. VM9, a porcelain veneer component of crown/bridge structure, is slightly softer than its core, Mark II. The yield point for Mark II and VM9 are nearly 10 and 7GPa, respectively, and approximately 2GPa for Wiron alloy and enamel.
SIGNIFICANCE
H-a/R curves provide a new method to compare the mechanical properties of different dental materials. From the standpoint of structural reliability, strong and tough materials with primarily elastic response, such as toughened ceramics are required to enable dental crown/bridges to have long term reliability. On the other hand, materials with too high hardness or yield response may damage opposing teeth during occlusal contact. Future studies may establish a relationship between stress and strain property and abrasive wear of dental material.
Topics: Dental Alloys; Dental Enamel; Dental Porcelain; Dental Stress Analysis; Elasticity; Hardness; Materials Testing; Surface Properties
PubMed: 16890985
DOI: 10.1016/j.dental.2006.06.017 -
Collegium Antropologicum 2003The purpose of this study was to examine how Co-Cr-Mo dental alloy behaves in the solutions of different pH value and different composition over a relatively long period...
The purpose of this study was to examine how Co-Cr-Mo dental alloy behaves in the solutions of different pH value and different composition over a relatively long period of time. Co-Cr-Mo dental alloy was exposed in vitro to either simulated saliva (phosphate buffer pH 6.0), a highly acidic medium resembling the extreme conditions in the oral cavity (phosphate buffer pH 3.5), and in lactic acid at pH which occurs under the dental plaque (lactic acid pH 3.5). The alloy samples were immersed in these three solution for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. Solutions were analysed with the ICP-AES. The analysis showed that during one month cobalt (Co), chromium (Cr), iron (Fe), zinc (Zn) and nickel (Ni) ions had been released from tested samples in all three solutions. The results of this study indicate that the leaching of the Co, Cr, Fe, Zn and Ni ions in the solution was dependent both upon the nature of the solution in which the alloy was immersed and the duration of the immersion (p < 0.001).
Topics: Chromium; Cobalt; Corrosion; Dental Alloys; Hydrogen-Ion Concentration; Ions; Molybdenum; Saliva; Time Factors
PubMed: 12971177
DOI: No ID Found -
Journal of Materials Science. Materials... Apr 2006The release of metal ions (Al, Ag, Au, Ca, Cd, Co, Cr, Cu, Mg, Mo, Ni, Pd, Pt, Ti, and Zn) from the commercial gold/platinum (Au/Pt) dental alloy of declared composition... (Comparative Study)
Comparative Study
OBJECTIVES
The release of metal ions (Al, Ag, Au, Ca, Cd, Co, Cr, Cu, Mg, Mo, Ni, Pd, Pt, Ti, and Zn) from the commercial gold/platinum (Au/Pt) dental alloy of declared composition was studied.
METHODS
Au/Pt was soaked in pH 6.0 phosphate buffer, 3.5 pH phosphate buffer and pH 3.5 mixture of lactic, formic and acetic acid, and incubated at 37 degrees C for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. Six samples (n = 6) of every solution were prepared for any time period. Inductively coupled plasma atomic emission spectroscopy was used for analysis of the released elements.
RESULTS
Results demonstrated release of only Cr, Cu, Fe, and Zn from the tested Au/Pt dental alloy (ANOVA, p < 0.001 for buffer, time, and interaction, respectively); however, only Cu and Zn were declared.
CONCLUSIONS
The undeclared chromium from Au/Pt dental alloy, or some other element might be responsible for the contact allergy thus far attributed to the gold.
Topics: Dental Alloys; Dermatitis, Contact; Gold; Humans; Ions; Materials Testing; Metals; Platinum; Risk Assessment; Risk Factors; Saliva
PubMed: 16617407
DOI: 10.1007/s10856-006-8225-y -
Dental Materials : Official Publication... Feb 2015Dental alloys containing indium (In) have been used in dental restoration for two decades; however, no study has investigated the biological effects of In ions, which...
OBJECTIVE
Dental alloys containing indium (In) have been used in dental restoration for two decades; however, no study has investigated the biological effects of In ions, which may be released in the oral cavity, on human oral keratinocytes. The objective of the present study was to investigate the biological effects of In ions on human oral keratinocyte after confirming their release from a silver-palladium-gold-indium (Ag-Pd-Au-In) dental alloy.
METHODS
As a corrosion assay, a static immersion tests were performed by detecting the released ions in the corrosion solution from the Ag-Pd-Au-In dental alloy using inductively coupled plasma atomic emission spectroscopy. The cytotoxicity and biological effects of In ions were then studied with In compounds in three human oral keratinocyte cell lines: immortalized human oral keratinocyte (IHOK), HSC-2, and SCC-15.
RESULTS
Higher concentrations of In and Cu ions were detected in Ag-Pd-Au-In (P<0.05) than in Ag-Pd-Au, and AgCl deposition occurred on the surface of Ag-Pd-Au-In after a 7-day corrosion test due to its low corrosion resistance. At high concentrations, In ions induced cytotoxicity; however, at low concentrations (∼0.8In(3+)mM), terminal differentiation was observed in human oral keratinocytes. Intracellular ROS was revealed to be a key component of In-induced terminal differentiation.
SIGNIFICANCE
In ions were released from dental alloys containing In, and high concentrations of In ions resulted in cytotoxicity, whereas low concentrations induced the terminal differentiation of human oral keratinocytes via increased intracellular ROS. Therefore, dental alloys containing In must be biologically evaluated for their safe use.
Topics: Blotting, Western; Cell Differentiation; Corrosion; Dental Alloys; Electrochemical Techniques; Enzyme-Linked Immunosorbent Assay; ErbB Receptors; Fibronectins; Gold Alloys; Humans; Indium; Ions; Keratinocytes; Keratins; Materials Testing; Palladium; Protein Precursors; Reactive Oxygen Species; Silver; Spectrophotometry, Atomic; X-Ray Diffraction
PubMed: 25498522
DOI: 10.1016/j.dental.2014.11.006 -
The Journal of Prosthetic Dentistry Dec 2012The effect of different proportions of recast dental alloys on the color of overlying opaque porcelain (OP) is unknown. (Comparative Study)
Comparative Study
STATEMENT OF PROBLEM
The effect of different proportions of recast dental alloys on the color of overlying opaque porcelain (OP) is unknown.
PURPOSE
The purpose of this study was to compare the color of OP applied on 2 different proportions (50% and 100%) of recast alloys with the color of commercially available shade tabs of OP.
MATERIAL AND METHODS
Six different metal alloy systems (2 base: Metalloy CC, Cr-Co [B-MCC]; Heraenium NA, Ni-Cr [B-HNA]; 3 noble: Cerapall 2, Pd-Au [N-CP2]; Triumph, Pd-Ag [N-T]; V-Deltaloy, Au-Pd [N-VD]; and 1 high-noble: V-Gnathos Plus, Au-Pt [HN-GP]) were selected for the fabrication of disk-shaped specimens (10 mm in diameter, 1 mm in thickness). Each alloy was divided into 2 subgroups: 50% new alloy with 50% recast alloy (n=3) and 100% recast alloy (n=3). OP (B1) was applied (0.1 mm) to all specimens. The color coordinates (L*, a*, b*) of each specimen and the corresponding commercially available OP shade tab (control) were measured with a spectroradiometer, and color differences between specimens and control group were calculated. Data were statistically analyzed (2-way ANOVA, Ryan-Einot-Gabriel-Welsch multiple range test, α=.05).
RESULTS
For each alloy, ΔL*(L(control)(-)L(recastalloy)) values for the 2 subgroups were not statistically different from each other. The Δa* and Δb* of different proportions of N-CP2, B-HNA, N-VD, and HN-GP were not statistically different within the alloys. However, the a* values of 100% recast N-T and B-MCC were significantly closer to the a* values of the control group, and the b* values of 50% recast B-MCC were significantly closer to the b* values of the control group (P<.05). Delta E(control-recast) alloy values for different proportions of alloys were not statistically different. However, color differences did not meet the criterion of clinical acceptability (ΔE=3.46).
CONCLUSIONS
According to the results of this study, the different proportions (50% and 100%) of recast alloys used have similar effects on the color of OP. Differences between the final color of OP on the recast alloys used and the color of OP shade guide tabs did not meet the criterion of clinical acceptability considered in this study.
Topics: Aluminum Oxide; Chromium Alloys; Color; Dental Alloys; Dental Casting Technique; Dental Etching; Dental Porcelain; Gold Alloys; Hot Temperature; Humans; Materials Testing; Palladium; Platinum; Prosthesis Coloring; Silver; Surface Properties; Vacuum
PubMed: 23217468
DOI: 10.1016/S0022-3913(12)60193-0 -
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi =... Jun 2000Although titanium and titanium alloy have been used in dental field for several years because of their excellent biocompatibility, corrosion resistance and mechanical... (Review)
Review
Although titanium and titanium alloy have been used in dental field for several years because of their excellent biocompatibility, corrosion resistance and mechanical properties, many practical problems remain to be solved. This review focuses on the practical problems and the prospects of the researches on titanium, including the development of new titanium alloy, the surface treating, the corrosion in oral, and the processability.
Topics: Corrosion; Dental Alloys; Dental Soldering; Dentistry; Titanium
PubMed: 12557781
DOI: No ID Found -
Dental Materials Journal Jul 2019The goal of this study was to investigate the chemical alteration of a dental alloy surface by alumina air-abrasion and its effect on bonding to resin cement. Alumina...
The goal of this study was to investigate the chemical alteration of a dental alloy surface by alumina air-abrasion and its effect on bonding to resin cement. Alumina air-abrasion was carried out on an Ag-Pd-Cu-Au alloy. The surface morphology and chemical state of the abraded alloy were characterized. The effect of the air-abrasion on the shear bond strength between the alloy and a methyl methacrylate/tri-n-butyl borane (MMA/TBB) resin cement with some primers was evaluated. The surface characterization revealed that the alumina air-abrasion mechanically roughened and chemically altered the surface. The chemical alterations had two effects: (1) abraded alumina particles remained on the alloy surface and (2) copper ions were oxidized in the alloy surface. As the result, the shear bond strength test indicated that 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer worked with the abraded alloy surface, whereas it did not work with the non-abraded alloy surface.
Topics: Aluminum Oxide; Dental Alloys; Dental Bonding; Dental Stress Analysis; Materials Testing; Resin Cements; Shear Strength; Surface Properties
PubMed: 30971652
DOI: 10.4012/dmj.2018-276