Radiopaque Shape Memory Alloys: NiTi–Er with Stable Superelasticity

Tuissi, A.; Carr, Shane; Butler, James D.; Gandhi, Abbasi A.; O’Donoghue, Lisa M.T.; McNamara, Karrina; Carlson, James M.; Lavelle, S.; Tiernan, Peter; Biffi, Carlo Alberto; Bassani, Paola; Tofail, Syed A. M.

doi:10.1007/s40830-016-0066-z

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…The density for α-Bi 2 O 3 , β-Ta 2 O 5 , and β-Bi 7.8 Ta 0.2 O 12.2 is 9.37, 8.31, and 9.18 g/cm 3 , respectively. The measured radiopacity did not follow the expected rule [ 26 ]. It is suggested that, in addition to the composition, the particle size distribution at various stages may affect the solidification of MTA-like cements and the radiopacity performance.…”

Section: Resultsmentioning

confidence: 99%

Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi2O3/Ta2O5 Composite Powders Prepared by Mechanical Milling

Lin

Chang

et al. 2021

Materials

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Among the various phases of bismuth oxide, the high temperature metastable face-centered cubic δ phase attracts great attention due to its unique properties. It can be used as an ionic conductor or an endodontic radiopacifying material. However, no reports concerning tantalum and bismuth binary oxide prepared by high energy ball milling and serving as a dental radiopacifier can be found. In the present study, Ta2O5-added Bi2O3 composite powders were mechanically milled to investigate the formation of these metastable phases. The as-milled powders were examined by X-ray diffraction and scanning electron microscopy to reveal the structural evolution. The as-milled composite powders then served as the radiopacifier within mineral trioxide aggregates (i.e., MTA). Radiopacity performance, diametral tensile strength, setting times, and biocompatibility of MTA-like cements solidified by deionized water, saline, or 10% calcium chloride solution were investigated. The experimental results showed that subsequent formation of high temperature metastable β-Bi7.8Ta0.2O12.2, δ-Bi2O3, and δ-Bi3TaO7 phases can be observed after mechanical milling of (Bi2O3)95(Ta2O5)5 or (Bi2O3)80(Ta2O5)20 powder mixtures. Compared to its pristine Bi2O3 counterpart with a radiopacity of 4.42 mmAl, long setting times (60 and 120 min for initial and final setting times) and 84% MG-63 cell viability, MTA-like cement prepared from (Bi2O3)95(Ta2O5)5 powder exhibited superior performance with a radiopacity of 5.92 mmAl (the highest in the present work), accelerated setting times (the initial and final setting time can be shortened to 25 and 40 min, respectively), and biocompatibility (94% cell viability).

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Section: Resultsmentioning

confidence: 99%

Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi2O3/Ta2O5 Composite Powders Prepared by Mechanical Milling

Lin

Chang

et al. 2021

Materials

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“…They usually situate into the stenosis supply route decisively on the demonstration of x‐ray fluoroscopy. The representation and following of stents under fluoroscopy, which is the most certain methodology for perception, is achieved either through the stent‘s innate retention of x‐rays or by the situation of radiopaque markers on the stent [146].…”

Section: Methods Applied On the Metal Surfacementioning

confidence: 99%

Commercial pure titanium – A potential candidate for cardiovascular stent

Mohanta

Thirugnanam

2022

Materialwissenschaft Werkst

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The most commonly used metal alloys for manufacturing coronary artery stents platforms are 316 L stainless steel, cobalt‐chromium, tantalum, and titanium alloys. Cobalt‐based alloys have several advantages: good flexibility, radial strength, and better radiopacity. But still, concern about their cytotoxicity exists. In comparison, commercially pure titanium possesses excellent corrosion resistance and biocompatibility properties. However, it faces a problem with its mechanical strength during the development of stents, thereby deteriorating its radial strength and making it a poor radiopaque element. This review illustrated the properties of titanium and strategies to overcome the disadvantages of commercially pure titanium: Surface treatment, polymer coating, and warm treatment. The importance of radiopacity and radial strength in post‐clinical imaging techniques and metals compatibility with the imaging devices are also introduced. The findings suggest that by controlling the springback effect via warm treatment, the elastic energy of commercially pure titanium decreases and hence, prevent the recoiling phenomenon. The reduction in the recoiling effect may improve the radial strength of titanium. This work has addressed the limitations of commercially pure titanium to overcome them in the future while developing as a cardiovascular stent.

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“…The photoelectron effect arising from the interaction of X-ray photos with inner-shell electrons is the dominant factor [21]. Radiopacifiers with high atomic number (Z) improve radiopacity by increasing the mass attenuation coefficient (µ) in accordance with the power law of µ ∞ Z 3 [22]. It shows almost no scattering radiation and results in a high-quality image.…”

Section: Introductionmentioning

confidence: 99%

A Novel Sol-Gel Bi2-xHfxO3+x/2 Radiopacifier for Mineral Trioxide Aggregates (MTA) as Dental Filling Materials

et al. 2021

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Mineral trioxide aggregate (MTA) is well known as an effective root canal filling material for endodontics therapy. Within MTA, bismuth oxide (Bi2O3) serving as the radiopacifier still has biocompatibility concerns due to its mild cytotoxicity. In the present study, we tried to modify the Bi2O3 radiopacifier by doping hafnium ions via the sol-gel process and investigated the effects of different doping ratios (Bi2-xHfxO3+x/2, x = 0–0.3) and calcination temperatures (400–800 °C). We mixed various precursor mixtures of bismuth nitrate (Bi(NO3)3·5H2O) and hafnium sulfate (Hf(SO4)2) and controlled the calcination temperatures. The as-prepared Hf-doped Bi2O3 radiopacifier powders were investigated by thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Portland cement/radiopacifier/calcium sulfate (75/20/5) were mixed and set by deionized water (powder to water ratio = 3:1). Changes in radiopacity, diametral tensile strength (DTS), and in vitro cell viability of the hydrated MTA-like cement were carried out. The experimental results showed that the group containing radiopacifier from sol-gelled Bi/Hf (90/10) exhibited significantly higher radiopacity (6.36 ± 0.34 mmAl), DTS (2.54 ± 0.29 MPa), and cell viability (84.0±8.1%) (p < 0.05) when compared to that of Bi/Hf (100/0) powders. It is suggested that the formation of β-Bi7.78Hf0.22O12.11 phase with hafnium addition and calcining at 700 °C can prepare novel bismuth/hafnium composite powder that can be used as an alternative radiopacifier for root canal filling materials.

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Radiopaque Shape Memory Alloys: NiTi–Er with Stable Superelasticity

Cited by 8 publications

References 13 publications

Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi2O3/Ta2O5 Composite Powders Prepared by Mechanical Milling

Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi2O3/Ta2O5 Composite Powders Prepared by Mechanical Milling

Commercial pure titanium – A potential candidate for cardiovascular stent

A Novel Sol-Gel Bi2-xHfxO3+x/2 Radiopacifier for Mineral Trioxide Aggregates (MTA) as Dental Filling Materials

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