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International Journal of Molecular... Apr 2023The purpose of this study is to evaluate the mechanical properties and clinical fitness of 3D-printed bioglass porcelain fused to metal (PFM) dental crowns. To evaluate...
The purpose of this study is to evaluate the mechanical properties and clinical fitness of 3D-printed bioglass porcelain fused to metal (PFM) dental crowns. To evaluate the mechanical properties, tensile strength, Vickers microhardness, shear bond strength, and surface roughness tests of the SLM printed Co-Cr alloy was conducted. A right mandibular 1st molar tooth was prepared for a single dental crown ( = 10). For a three-unit metal crown and bridge, the right mandibular first premolar and first molar were prepared. Bioglass porcelain was fired to fabricate PFM dental restorations. A clinical gap was observed and measured during each of the four times porcelain was fired. A statistical analysis was conducted. The SLM technique showed the largest statistically significant tensile strength and a 0.2% yield strength value. The milling technique had the lowest statistically significant compressive strength value. The shear bond strength and surface roughness showed no statistically significant difference between the fabricated method. There was a statistically significant change in marginal discrepancy according to the porcelain firing step. The casting technique showed the greatest statistically significant margin discrepancy value. The SLM method showed better fitness than the traditional casting method and showed better mechanical properties as a dental material.
Topics: Metal Ceramic Alloys; Dental Porcelain; Chromium Alloys; Materials Testing; Surface Properties; Printing, Three-Dimensional; Crowns
PubMed: 37108364
DOI: 10.3390/ijms24087203 -
Dental Materials : Official Publication... Mar 2018To characterize the microstructure, mechanical properties, ionic release and tarnish resistance of conventional and experimental Ag-based soldering alloys for...
OBJECTIVES
To characterize the microstructure, mechanical properties, ionic release and tarnish resistance of conventional and experimental Ag-based soldering alloys for orthodontic applications.
METHODS
Disk shaped specimens were prepared from four commercial Ag based soldering alloys [Dentaurum Universal Silver Solder (DEN), Orthodontic Solders (LEO), Ortho Dental Universal Solder (NOB), and Silver Solder (ORT)] and four experimental alloys Ag12Ga, Ag10Ga5Sn, Ag20In and Ag7Sn. The elemental composition and microstructure was determined by SEM/EDX and XRD analysis, while the mechanical properties were determined by Instrumented Indentation Testing. Ionic release of Ag, Cu, Zn, Ga, In and Sn was determined by ICP-EAS in 0.9% NaCl and Ringer's solutions after 28, 49 and 70 days. Tarnish resistance was also tested and colorimetry was applied to quantify the differences in color (DE) before and after immersion in testing media. DSC was used to determine the melting range of the experimental alloys. Mechanical properties, ionic release and DE were statistically compared by ANOVA and Holm-Sidak multiple comparison test (a=0.05).
RESULTS
All commercially alloys belong to the Ag-Zn-Cu ternary system and consist a Ag rich face centered cubic (FCC) and Cu (FCC) phase. The former is the predominant phase also in experimental alloys. Conventional alloys demonstrated higherhardness, less ductility and lower melting rangers compared to experimental alloys. Immersion testing revealed the release of Cu and Zn ions from the commercially alloys and Ga ions from AgGa and AgGaSn while no ionic release was identified for AgIn and AgSn. All alloys failed tarnish testing according to ISO 10271 showing DE values much higher than the clinical acceptable limit (3.7).
SIGNIFICANCE
The conventional Ag based soldering alloys showed substantial differences in their microstructure, mechanical properties and ionic release, and thus different clinical performance is anticipated. Ga, Sn and In might be employed as alloying addition to modify the properties of Ag brazing alloys.
Topics: Colorimetry; Dental Alloys; Dental Soldering; Materials Testing; Microscopy, Electron, Scanning; Orthodontics; Silver; Spectrometry, X-Ray Emission; X-Ray Diffraction
PubMed: 29395471
DOI: 10.1016/j.dental.2018.01.003 -
BMC Oral Health Oct 2023The aim of this study was to evaluate the phase composition, phase transformation temperatures, bending property, and cyclic fatigue resistance of different heat-treated...
BACKGROUND
The aim of this study was to evaluate the phase composition, phase transformation temperatures, bending property, and cyclic fatigue resistance of different heat-treated nickel-titanium (NiTi) rotary instruments with the same tip diameter and taper at room (RT; 25 ± 1 °C) and body (BT; 37 ± 1 °C) temperatures.
METHODS
Five heat-treated NiTi rotary instruments, HyFlex EDM (EDM), HyFlex CM (CM), Vortex Blue (VB), RE file CT (RE) and JIZAI, and a non-heat-treated NiTi rotary instrument (Mtwo) with a size 40, 0.04 taper were investigated. Temperature-dependent phase transformation was examined with differential scanning calorimetry (DSC). The bending loads of the instruments at RT and BT were evaluated using a cantilever-bending test. Cyclic fatigue resistance at RT and BT was measured using a dynamic test, during which the instruments were rotated in combination with a 2-mm back-and-forth motion in an artificial curved canal, and the number of cycles to failure (NCF) was determined. The results were analyzed using two-way repeated measures analysis of variance, a simple main effect test, and the Bonferroni test (α = 0.05).
RESULTS
DSC results indicated that EDM and Mtwo were primarily composed of martensite/R-phase and austenite, respectively, while the other heat-treated instruments were composed of a mix of martensite/R-phase and austenite at the tested temperatures. Regardless of the temperature setting, the bending loads of heat-treated instruments were significantly lower than those of Mtwo (p < 0.05). EDM showed the lowest bending loads and highest NCF at both temperatures (p < 0.05). CM, VB, and JIZAI showed significantly higher bending loads at BT than at RT (p < 0.05). The NCF of all the heat-treated instruments, except VB, was lower at BT than at RT (p < 0.05). At BT, the NCF of CM, VB, RE, and JIZAI were not significantly higher than that of Mtwo (p > 0.05).
CONCLUSIONS
Heat-treated NiTi instruments exhibited lower bending loads and higher NCF values than Mtwo. However, this tendency was less pronounced at BT than at RT, especially in the NCF values of instruments with a mixture of martensite/R-phase and austenite phases at the tested temperatures.
Topics: Humans; Hot Temperature; Titanium; Nickel; Body Temperature; Equipment Failure; Dental Alloys; Materials Testing; Dental Instruments; Root Canal Preparation; Stress, Mechanical
PubMed: 37904159
DOI: 10.1186/s12903-023-03550-6 -
International Journal of Oral Science Mar 2013This paper aims to investigate if the dental restoration of nickel-chromium based alloy (Ni-Cr) leads to the enhanced excretions of Ni and Cr in urine. Seven hundred and... (Comparative Study)
Comparative Study
This paper aims to investigate if the dental restoration of nickel-chromium based alloy (Ni-Cr) leads to the enhanced excretions of Ni and Cr in urine. Seven hundred and ninety-five patients in a dental hospital had single or multiple Ni-Cr alloy restoration recently and 198 controls were recruited to collect information on dental restoration by questionnaire and clinical examination. Urinary concentrations of Ni and Cr from each subject were measure by graphite furnace atomic absorption spectrometry. Compared to the control group, the urinary level of Ni was significantly higher in the patient group of <1 month of the restoration duration, among which higher Ni excretions were found in those with either a higher number of teeth replaced by dental alloys or a higher index of metal crown not covered with the porcelain. Urinary levels of Cr were significantly higher in the three patient groups of <1, 1 to <3 and 3 to <6 months, especially in those with a higher metal crown exposure index. Linear curve estimations showed better relationships between urinary Ni and Cr in patients within 6-month groups. Our data suggested significant increased excretions of urinary Ni and Cr after dental restoration. Potential short- and long-term effects of Ni-Cr alloy restoration need to be investigated.
Topics: Adult; Chromium; Chromium Alloys; Creatinine; Crowns; Dental Porcelain; Female; Humans; Male; Metal Ceramic Alloys; Middle Aged; Nickel; Spectrophotometry, Atomic; Surface Properties; Time Factors
PubMed: 23579466
DOI: 10.1038/ijos.2013.13 -
Journal of Radiation Research Nov 2016The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au-Ag-Pd dental alloy; DA) were investigated to identify the...
The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au-Ag-Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 × 10 cm using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 1-10 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of ≥5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of ≥4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose.
Topics: Dental Alloys; Gold; Humans; Mucositis; Palladium; Particle Accelerators; Phantoms, Imaging; Polyethylene Terephthalates; Radiation Dosage; Radiation Protection; Radiotherapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Scattering, Radiation; Silver
PubMed: 27702778
DOI: 10.1093/jrr/rrw092 -
Dental Materials : Official Publication... Nov 2020To investigate the metal ion release, surface roughness and cytoxicity for Co-Cr alloys produced by different manufacturing techniques before and after heat treatment....
OBJECTIVE
To investigate the metal ion release, surface roughness and cytoxicity for Co-Cr alloys produced by different manufacturing techniques before and after heat treatment. In addition, to evaluate if the combination of materials affects the ion release.
METHODS
Five Co-Cr alloys were included, based on four manufacturing techniques. Commercially pure titanium, CpTi grade 4 and a titanium alloy were included for comparison. The ion release tests involved both Inductive Coupled Plasma Optical Emission Spectrometry and Inductive Coupled Plasma Mass Spectrometry analyses. The surface analysis was conducted with optical interferometry. Cells were indirectly exposed to the materials and cell viability was evaluated with the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) method.
RESULTS
All alloys showed a decrease of the total ion release when CpTi grade 4 was present. The total ion release decreased over time for all specimens and the highest ion release was observed from the cast and milled Co-Cr alloy in acidic conditions. The cast and laser-melted Co-Cr alloy and the titanium alloy became rougher after heat treatment. All materials were within the limits of cell viability according to standards.
SIGNIFICANCE
The ion release from Co-Cr alloys is influenced by the combination of materials, pH and time. Surface roughness is influenced by heat treatment. Furthermore, both ion release and surface roughness are influenced by the manufacturing technique and the alloy type. The clinical implication needs to be further investigated.
Topics: Alloys; Chromium Alloys; Cobalt; Dental Alloys; Materials Testing; Surface Properties
PubMed: 32943232
DOI: 10.1016/j.dental.2020.08.012 -
Dental Materials Journal Jul 2021Titanium are often used as dental materials, pure titanium present low strength and titanium alloy is reported poor biocompatibility, respectively. To overcome the...
Titanium are often used as dental materials, pure titanium present low strength and titanium alloy is reported poor biocompatibility, respectively. To overcome the problem, we fabricated high-strength multi-directional forged (MDF) titanium with improved mechanical properties without changing the chemical composition and evaluated its applicability in prosthetic crowns. Cutting tests: the average absolute value of the difference before and after cutting was calculated as the uncut amount. Surface evaluations: MDF titanium, pure titanium, and the Ti-6Al-4V alloy were the surface properties (the surface roughness, the contact angles, glossiness) of the samples were evaluated. The fitness test used digital data. These demonstrated that the good workability of high-strength MDF titanium. The surface-roughness and contact-angle properties of MDF titanium and pure titanium were similar. The fitness test showed no significant differences between MDF titanium and pure titanium crowns. These results suggest that MDF titanium is promising for fabricating prosthetic crowns in dental applications.
Topics: Computer-Aided Design; Crowns; Dental Alloys; Materials Testing; Surface Properties; Titanium
PubMed: 33883352
DOI: 10.4012/dmj.2020-351 -
BioMed Research International 2019Dental implants are often made of titanium alloys. Implant therapy currently promises a good long-term result without impacting health; however, its success depends on... (Review)
Review
Dental implants are often made of titanium alloys. Implant therapy currently promises a good long-term result without impacting health; however, its success depends on many factors. In this article, the authors focus on the most common risk factors associated with metallic surgical implants. Titanium-induced hypersensitivity can lead to symptoms of implant rejection. Corrosion and biofilm formation are additional situations in which these symptoms may occur. For medical purposes, it is important to define and discuss the characteristics of metals used in implantable devices and to ensure their biocompatibility. To avoid hypersensitivity reactions to metallic dental implants, precautionary principles for primary prevention should be established.
Topics: Biocompatible Materials; Corrosion; Dental Alloys; Dental Implants; Humans; Metals; Risk Factors; Titanium
PubMed: 31360706
DOI: 10.1155/2019/2519205 -
Dental Materials Journal Jan 2021Binary Ti-Fe alloys with 5-25 mass% Fe were prepared, and subjected to reciprocating wear test. The aim of this study was to investigate the relationship between...
Binary Ti-Fe alloys with 5-25 mass% Fe were prepared, and subjected to reciprocating wear test. The aim of this study was to investigate the relationship between mechanical properties and the wear resistance of titanium and Ti-Fe alloys. The dimensions (length, width and depth) of wear marks on Ti-Fe alloys were less than those observed on pure Ti specimen. Wear resistance of Ti-Fe alloys was better than that of pure titanium. It was established that hardness was the main factor that influenced wear resistance of Ti-Fe alloys. Single β Ti-Fe alloys showed better wear resistance than α+β Ti-Fe alloys. Increase in concentration of Fe in the β phase of Ti-Fe alloys leads to improved wear resistance of the alloy. Ti-Fe alloys with 11-15 mass% Fe form ideal candidates for fabrication of dental titanium alloys with excellent wear resistance.
Topics: Alloys; Dental Alloys; Hardness; Materials Testing; Titanium
PubMed: 32848102
DOI: 10.4012/dmj.2019-336 -
PloS One 2012Artifacts caused by dental restorations, such as dental crowns, dental fillings and orthodontic appliances, are a common problem in MRI and CT scans of the head and...
BACKGROUND
Artifacts caused by dental restorations, such as dental crowns, dental fillings and orthodontic appliances, are a common problem in MRI and CT scans of the head and neck. The aim of this in-vitro study was to identify and evaluate the artifacts produced by different dental restoration materials in CT and MRI images.
METHODS
Test samples of 44 materials (Metal and Non-Metal) commonly used in dental restorations were fabricated and embedded with reference specimens in gelatin moulds. MRI imaging of 1.5T and CT scan were performed on the samples and evaluated in two dimensions. Artifact size and distortions were measured using a digital image analysis software.
RESULTS
In MRI, 13 out of 44 materials produced artifacts, while in CT 41 out of 44 materials showed artifacts. Artifacts produced in both MRI and CT images were categorized according to the size of the artifact.
SIGNIFICANCE
Metal based restoration materials had strong influence on CT and less artifacts in MRI images. Rare earth elements such as Ytterbium trifluoride found in composites caused artifacts in both MRI and CT. Recognizing these findings would help dental materials manufacturers and developers to produce materials which can cause less artifacts in MRI and CT images.
Topics: Artifacts; Composite Resins; Crowns; Dental Alloys; Dental Amalgam; Dental Materials; Fluorides; Humans; Magnetic Resonance Imaging; Reproducibility of Results; Tomography, X-Ray Computed; Ytterbium; Zirconium
PubMed: 22384071
DOI: 10.1371/journal.pone.0031766