-
Dental Materials Journal Mar 2020The aim of this paper is to study changes in the Ag-Pd-Cu-Au alloy surfaces by alumina air-abrasion process and effect of those changes on the adhesive bonding...
The aim of this paper is to study changes in the Ag-Pd-Cu-Au alloy surfaces by alumina air-abrasion process and effect of those changes on the adhesive bonding characteristic. Surface roughness, surface composition and chemical state of the alumina air-abraded alloys were analyzed by a confocal laser scanning microscope, an energy dispersive X-ray spectroscopy and an X-ray photoelectron spectroscopy. The results showed that the alumina air-abrasion changed the alloy surface by mechanical roughening, alumina remain and copper oxidation. Effect of the changes in the alloy surface on the adhesive bonding characteristic was examined by using a methyl methacrylate/tri-n-butylborane derivative (MMA/TBB) resin cement with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) contained primer. The shear bond strength test results indicated that the surface oxidation by the abrasion is the main contributor that improved the adhesive bonding rather than other effects such as mechanical roughening or alumina remain.
Topics: Aluminum Oxide; Dental Alloys; Dental Bonding; Dental Cements; Materials Testing; Methacrylates; Resin Cements; Shear Strength; Surface Properties
PubMed: 31723095
DOI: 10.4012/dmj.2019-027 -
Scientific Reports Nov 2016In the present study, the microstructure, mechanical property, castability, corrosion behavior and in vitro cytocompatibility of binary Ti-2X alloys with various...
In the present study, the microstructure, mechanical property, castability, corrosion behavior and in vitro cytocompatibility of binary Ti-2X alloys with various alloying elements, including Ag, Bi, Ga, Ge, Hf, In, Mo, Nb, Sn and Zr, were systematically investigated, in order to assess their potential applications in dental field. The experimental results showed that all binary Ti‒2X alloys consisted entirely α-Ti phase. The tensile strength and microhardness of Ti were improved by adding alloying elements. The castability of Ti was significantly improved by separately adding 2 wt.% Bi, Ga, Hf, Mo, Nb, Sn and Zr. The corrosion resistance of Ti in both normal artificial saliva solution (AS) and extreme artificial saliva solution (ASFL, AS with 0.2 wt.% NaF and 0.3 wt.% lactic acid) has been improved by separately adding alloying elements. In addition, the extracts of studied Ti‒2X alloys produced no significant deleterious effect to both fibroblasts L929 cells and osteoblast-like MG63 cells, indicating a good in vitro cytocompatibility, at the same level as pure Ti. The combination of enhanced mechanical properties, castability, corrosion behavior, and in vitro cytocompatibility make the developed Ti‒2X alloys have great potential for future stomatological applications.
Topics: Alkaline Phosphatase; Animals; Cell Line; Cell Survival; Corrosion; Dental Alloys; Dental Casting Technique; Dental Prosthesis; Electrochemistry; Hardness; Humans; Materials Testing; Mechanical Phenomena; Mice; Tensile Strength; Titanium; X-Ray Diffraction
PubMed: 27874034
DOI: 10.1038/srep37428 -
The Angle Orthodontist Jul 2006The purpose of this study was to provide a quantitative assessment of galvanic corrosion behavior of orthodontic archwire alloys coupled to orthodontic bracket alloys in...
The purpose of this study was to provide a quantitative assessment of galvanic corrosion behavior of orthodontic archwire alloys coupled to orthodontic bracket alloys in 0.9% NaCl solution and to study the effect of surface area ratios. Two common bracket alloys, stainless steels and titanium, and four common wire alloys, nickel-titanium (NiTi) alloy, beta-titanium (beta-Ti) alloy, stainless steel, and cobalt-chromium-nickel alloy, were used. Three different area ratios, 1:1, 1:2.35, and 1:3.64, were used; two of them assumed that the multibracket appliances consists of 14 brackets and 0.016 inch of round archwire or 0.016 x 0.022 inch of rectangular archwire. The galvanic current was measured for 3 successive days using zero-impedance ammeter. When the NiTi alloy was coupled with Ti (1:1, 1:2.35, and 1:3.64 of the surface area ratio) or beta-Ti alloy was coupled with Ti (1:2.35 and 1:3.64 of the surface area ratio), Ti initially was the anode and corroded. However, the polarity reversed in 1 hour, resulting in corrosion of the NiTi or beta-Ti. The NiTi alloy coupled with SUS 304 or Ti exhibited a relatively large galvanic current density even after 72 hours. It is suggested that coupling SUS 304-NiTi and Ti-NiTi may remarkably accelerate the corrosion of NiTi alloy, which serves as the anode. The different anode-cathode area ratios used in this study had little effect on galvanic corrosion behavior.
Topics: Chromium Alloys; Corrosion; Dental Alloys; Dental Materials; Electric Impedance; Electrochemistry; Humans; Materials Testing; Nickel; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Sodium Chloride; Stainless Steel; Surface Properties; Time Factors; Titanium
PubMed: 16808581
DOI: 10.1043/0003-3219(2006)076[0705:GCBOOA]2.0.CO;2 -
Federal Register Jun 2010The Food and Drug Administration (FDA) published a final rule in the Federal Register of August 4, 2009 (74 FR 38686) which classified dental amalgam as a class II...
Dental devices: classification of dental amalgam, reclassification of dental mercury, designation of special controls for dental amalgam, mercury, and amalgam alloy; technical amendment. Final rule; technical amendment.
The Food and Drug Administration (FDA) published a final rule in the Federal Register of August 4, 2009 (74 FR 38686) which classified dental amalgam as a class II device, reclassified dental mercury from class I to class II, and designated special controls for dental amalgam, mercury, and amalgam alloy. The effective date of the rule was November 2, 2009. The final rule was published with an inadvertent error in the codified section. This document corrects that error. This action is being taken to ensure the accuracy of the agency's regulations.
Topics: Dental Alloys; Dental Amalgam; Device Approval; Humans; Mercury; Mercury Compounds; United States
PubMed: 20540224
DOI: No ID Found -
The Angle Orthodontist Nov 2021To evaluate the ability of different esthetic archwires to retain oral biofilms in vitro.
OBJECTIVES
To evaluate the ability of different esthetic archwires to retain oral biofilms in vitro.
MATERIALS AND METHODS
Seven different brands of coated orthodontic archwires were tested: two epoxy coated, two polytetrafluoroethylene coated, two rhodium coated, and one silver plus polymer coated. Conventional uncoated metallic archwires were used as controls. Streptococus mutans adherence to archwires was quantified by colony count following 24 hours of biolfilm growth, and total wire-associated biofilm was measured using a crystal violet staining assay. For both tests, two conditions were used: 0% sucrose and 3% sucrose. For statistical analysis, P < .05 was considered as statistically significant.
RESULTS
For S. mutans colony forming units per biofilm, there were no statistically significant differences among the various archwires (P = .795 for 0% sucrose; P = .905 for 3% sucrose). Regarding total biofilm formed on archwires in the 3% sucrose condition, there were statistically significant differences in crystal violet staining only for the comparison between Niti Micro Dental White and Copper Ni-Ti wires (P < .05).
CONCLUSIONS
The clinical use of esthetic-coated orthodontic wires may be considered to have similar risks as uncoated archwires for biofilm retention.
Topics: Biofilms; Dental Alloys; Esthetics, Dental; Materials Testing; Orthodontic Wires; Streptococcus mutans; Surface Properties
PubMed: 34111239
DOI: 10.2319/121220-998.1 -
International Journal of Molecular... Oct 2020Compositions of stainless steel, nickel-titanium, cobalt-chromium and β-titanium orthodontic alloys were simulated with mixtures of Fe, Ni, Cr, Co, Ti and Mo metal ions...
Compositions of stainless steel, nickel-titanium, cobalt-chromium and β-titanium orthodontic alloys were simulated with mixtures of Fe, Ni, Cr, Co, Ti and Mo metal ions as potential oxidative stress-triggering agents. Wild-type yeast and two mutants ΔSod1 and ΔCtt1 were used as model organisms to assess the cytotoxicity and oxidative stress occurrence. Metal mixtures at concentrations of 1, 10, 100 and 1000 µM were prepared out of metal chlorides and used to treat yeast cells for 24 h. Every simulated orthodontic alloy at 1000 µM was cytotoxic, and, in the case of cobalt-chromium alloy, even 100 µM was cytotoxic. Reactive oxygen species and oxidative damage were detected for stainless steel and both cobalt-chromium alloys at 1000 µM in wild-type yeast and 100 µM in the ΔSod1 and ΔCtt1 mutants. Simulated nickel-titanium and β-titanium alloy did not induce oxidative stress in any of the tested strains.
Topics: Chromium Alloys; Dental Alloys; Materials Testing; Mutation; Nickel; Oxidative Stress; Reactive Oxygen Species; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Stainless Steel; Titanium
PubMed: 33121155
DOI: 10.3390/ijms21217993 -
The Angle Orthodontist 1997The materials used by orthodontists have changed rapidly in recent years and will continue to do so in the future. As esthetic composite archwires are introduced,... (Review)
Review
The materials used by orthodontists have changed rapidly in recent years and will continue to do so in the future. As esthetic composite archwires are introduced, metallic archwires will likely be replaced for most orthodontic applications in the same way that metals have been replaced by composites in the aerospace industry. Archwires are reviewed in the order of their development, with emphasis on specific properties and characteristics, such as strength, stiffness, range, formability, and weldability. Because an ideal material has not yet been found, archwires should be selected within the context of their intended use during treatment.
Topics: Chemical Phenomena; Chemistry, Physical; Composite Resins; Dental Alloys; Dental Soldering; Esthetics, Dental; Forecasting; Humans; Orthodontic Appliance Design; Orthodontic Wires; Pliability; Stress, Mechanical
PubMed: 9188964
DOI: 10.1043/0003-3219(1997)067<0197:AROCAT>2.3.CO;2 -
Dental Materials Journal May 2010Artifacts in MR(Magnetic Resonance) images of oral cavity produced from non-magnetic metal restorations was verified by measuring the image of index finger and a...
Artifacts in MR(Magnetic Resonance) images of oral cavity produced from non-magnetic metal restorations was verified by measuring the image of index finger and a cylinder of fat test piece with a type 4 gold alloy ring using a compact MRI equipment. In the images of finger, portion around the ring disappeared. However, it was nearly restored with a cut ring. In the cylinder of fat test piece, obvious artifacts appeared when circumferential surface of the ring was placed perpendicular to RF(Radio Frequency) field of MRI equipment's excitation/detection coil. However, in other directions or with a cut ring, artifact disappeared. The cause was simulated with FEM(Finite Element Method) electromagnetic field analysis, and alternating magnetic field was shown to induce surface current on the continuous gold ring. Magnetic field produced by that current interfered with the field from excitation coil. This demonstrated the characteristics and cause of artifacts by non-magnetic dental metals.
Topics: Adipose Tissue; Artifacts; Dental Alloys; Electromagnetic Fields; Finite Element Analysis; Gold Alloys; Humans; Magnetic Resonance Imaging; Radio Waves
PubMed: 20448408
DOI: 10.4012/dmj.2009-116 -
Dental Materials Journal Sep 2023The aim of this study was to investigate the effect of repeated casting and heat treatment on the corrosion resistance of a commercial Ag-Pd-Cu-Au alloy as evaluated by...
The aim of this study was to investigate the effect of repeated casting and heat treatment on the corrosion resistance of a commercial Ag-Pd-Cu-Au alloy as evaluated by electrochemical techniques. After repeated casting, the fifth cast of the Ag-Pd-Cu-Au alloy exhibited dramatic degradation of properties, although upon heat treatment, this corrosion resistance did improve. Despite the improvement by heat treatment, after five castings, this alloy may not have satisfactory hardness for clinical use. These results of this study demonstrate that, up to the fourth cast and heat treatment, the Ag-Pd-Cu-Au alloy has acceptable corrosion resistance and hardness.
Topics: Alloys; Copper; Corrosion; Dental Alloys; Gold Alloys; Hot Temperature; Materials Testing; Palladium; Silver; Dental Casting Technique
PubMed: 37612059
DOI: 10.4012/dmj.2023-032 -
Dental Materials Journal 2011This study evaluated the shear bond strength, failure modes, and confocal microscopy of two different amalgam alloy restorations lined with five adhesive systems. Two... (Comparative Study)
Comparative Study Randomized Controlled Trial
This study evaluated the shear bond strength, failure modes, and confocal microscopy of two different amalgam alloy restorations lined with five adhesive systems. Two regular-set high-copper dental amalgam alloys, Amalcap Plus and Valiant Ph.D, and five commercially available adhesive systems were selected. One hundred and twenty freshly-extracted human third molars were used for the study. The results were statistically evaluated using two-factor analysis of variance (ANOVA). The shear bond strength (SBS) of amalgam to dentin was significantly affected by both the adhesive (p<0.0001) and amalgam alloy (p<0.0002). Regarding mode of failure (MF), among samples restored with Valiant Ph.D, 31 of 50 exhibited adhesive failure, and 19 displayed mixed failure. Laser optical microscopy (OM) of the bonded interface revealed the presence of a good hybrid layer was evident in all experimental groups. Higher bond strengths were measured for four of the five adhesives when used in combination with the spherical alloy.
Topics: Acid Etching, Dental; Adhesiveness; Coloring Agents; Dental Alloys; Dental Amalgam; Dental Cavity Lining; Dental Restoration, Permanent; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Humans; Methacrylates; Microscopy, Confocal; Polymethacrylic Acids; Resin Cements; Self-Curing of Dental Resins; Shear Strength; Stress, Mechanical
PubMed: 21383518
DOI: 10.4012/dmj.2010-118