Reduction of Ni release and improvement of the friction behaviour of NiTi orthodontic archwires by oxidation treatments

Espinar, Eduardo; Llamas, J.M.; Michiardi, Alexandra; Ginebra, Maria‐Pau; Gil, F.J.

doi:10.1007/s10856-011-4292-9

Cited by 34 publications

(12 citation statements)

References 31 publications

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“…The presence and the integrity of a superficial titanium oxide layer is, in fact, a key factor in limiting the biodegradation of NiTi biomaterials. 25 It should be noted that BioTorque was the only rectangular NiTi wire considered in our study (0.019 3 0.025 inch), and this characteristic, together with the different manufacturing process employed for its production, could explain its higher cytotoxicity expressed compared to all the other NiTi wires having a round section.…”

Section: Discussionmentioning

confidence: 82%

In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires

Rongo

Valletta

Bucci

et al. 2016

The Angle Orthodontist

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Objective: To investigate the cytotoxicity of nickel-titanium (NiTi) esthetic orthodontic archwires with different surface coatings. Materials and Methods: Three fully coated, tooth-colored NiTi wires (BioCosmetic, Titanol Cosmetic, EverWhite), two ion-implanted wires (TMA Purple, Sentalloy High Aesthetic), five uncoated NiTi wires (BioStarter, BioTorque, Titanol Superelastic, Memory Wire Superelastic, and Sentalloy), one b-titanium wire (TMA), and one stainless steel wire (Stainless Steel) were considered for this study. The wire samples were placed at 37uC in airtight test tubes containing Dulbecco's Modified Eagle's Medium (0.1 mg/mL) for 1, 7, 14, and 30 days. The cell viability of human gingival fibroblasts (HGFs) cultured with this medium was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data were analyzed by a twoway analysis of variance (a 5 .05). Results: The highest cytotoxic effect was reached on day 30 for all samples. The archwires exhibited a cytotoxicity on HGFs ranging from "none" to "slight," with the exception of the BioTorque, which resulted in moderate cytotoxicity on day 30. Significant differences were found between esthetic archwires and their uncoated pairs only for BioCosmetic (P 5 .001) and EverWhite (P , .001). Conclusions: Under the experimental conditions, all of the NiTi esthetic archwires resulted in slight cytotoxicity, as did the respective uncoated wires. For this reason their clinical use may be considered to have similar risks to the uncoated archwires. (Angle Orthod. 2016;86:789-795.)

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Section: Discussionmentioning

confidence: 82%

In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires

Rongo

Valletta

Bucci

et al. 2016

The Angle Orthodontist

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“…22,30,71,84) For the Ti-Nb binary system, Ti-(26-27) at% Nb alloys exhibit superelasticity at room temperature while shape memory effect is observed in Ti- (20)(21)(22)(23)(24)(25) at% Nb alloys as shown in Fig. 6.…”

Section: Shape Memory Effect and Superelasticity In Ti-nb Binary Alloysmentioning

confidence: 93%

Martensitic Transformation and Superelastic Properties of Ti-Nb Base Alloys

2015

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Ti-Nb base alloys have been proposed as prospective candidates for Ni-free biomedical superelastic alloys due to their excellent mechanical properties with good biocompatibility, and many kinds of Ti-Nb base alloys exhibiting shape memory effect or superelasticity have been developed up to now. However, typical Ti-Nb base superelastic alloys show a small recovery strain which is less than one third of the recovery strain of practical Ti-Ni superelastic alloys. Over the last decade there have been extensive efforts to improve the properties of Ti-Nb base superelastic alloys through microstructure control and alloying. Low temperature annealing and aging are very effective to increase the critical stress for slip due to fine subgrain structure and precipitation hardening. The addition of interstitial alloying elements such as O and N raises the critical stress for slip and improves superelastic properties. In this paper, the roles of alloying elements on the martensitic transformation temperature, crystal structure, microstructure and deformation behavior in the Ti-Nb base alloys are reviewed and the alloy design strategy for biomedical superelastic alloys is proposed.

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“…These metallic ions pose a potential health hazard capable of inducing allergic reactions or even promoting the onset of cancer. [17][18][19] Several researches had previously investigated the selective leaching behaviour of TiNi and TiNiCu SMAs [20][21][22][23] ; however, the selective leaching of Ti, Ni, and Fe ions released from TiNiFe SMAs has not been studied. Therefore, this study investigated the selective leaching and surface properties of Ti 50 Ni 50-x Fe x (x = 1, 2, and 3) SMAs using inductively coupled plasma mass spectrometry (ICP-MS), an X-ray diffraction (XRD) analysis, electrochemical tests, and X-ray photoelectron spectroscopy (XPS).…”

Section: Introductionmentioning

confidence: 99%

Selective leaching and surface properties of TiNiFe shape-memory alloys

Chang¹,

Liou²,

Huang³

2017

Mater. tehnol.

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This study investigated the selective leaching and surface characteristics of Ti50Ni50-xFex (x = 1, 2, and 3) shape-memory alloys using inductively coupled plasma-mass spectrometry, X-ray diffractometry, electrochemical tests and X-ray photoelectron spectroscopy. According to our results, the concentrations of Ni and Fe ions selectively leached from each specimen were considerably higher than that of Ti ions. Electrochemical tests revealed a gradual deterioration in the corrosion resistance of the Ti50Ni50-xFex SMAs as the Fe content in the alloys was increased. X-ray photoelectron-spectroscopy results indicate that the surface of each specimen is primarily made up of a passive TiO2 film. NiO and Fe2O3 oxides, which also formed on the surfaces of the Ti50Ni50-xFex SMAs, caused a deterioration of the uniformity, undermining the protective effect of the TiO2 films, resulting in a highly selective leaching of the Ni and Fe ions. The Ti50Ni50-xFex SMAs exhibit a number of favourable properties compared to the other SMAs; however, high concentrations of selectively leached Ni and Fe ions may pose a risk in biomedical applications, particularly when used as implant materials. Keywords: TiNiFe shape-memory alloys, biomaterials, selective leaching, corrosion, X-ray photoelectron spectroscopy V {tudiji je prou~evano selektivno izpiranje in zna~ilnosti povr{ine zlitine s spominom Ti50Ni50-xFex (x = 1, 2, in 3), z uporabo masne spektrometrije z induktivno sklopljeno plazmo, rentgensko difrakcijo, elektrokemijskimi preizkusi in rentgensko fotoelektronsko spektroskopijo. Rezultati ka`ejo, da je bila koncentracija selektivno izpranih Ni in Fe ionov iz vsakega vzorca veliko ve~ja kot pa Ti ionov. Elektrokemijski preizkusi so pokazali postopno zmanj{anje korozijske odpornosti Ti50Ni50-xFex SMA, ko je vsebvnost Fe v zlitinah nara{~ala. Rezultati rentgenske fotoelektronske spektroskopije ka`ejo, da je povr{ina vseh vzorcev predvsem sestavljena iz pasivnih TiO2 plasti. NiO in Fe2O3 oksidi, ki so tudi nastali na povr{ini Ti50Ni50-xFex SMAs, poslab{ajo enotnost in ogro`ajo varovalno plast iz TiO2 prevlek, kar ima za posledico bolj selektivno izpiranje ionov Ni in Fe. Ti50Ni50-xFex SMAs vsebuje {tevilne ugodne lastnosti v primerjavi z drugimi SMA; vendar pa velika koncentracija selektivno izpranih Ni in Fe ionov lahko predstavlja tveganje pri biomedicinski uporabi, posebno pri implantiranih materialih. Klju~ne besede: TiNiFe zlitine s spominom, biomateriali, selektivno izpiranje, korozija, rentgenska fotoelektronska spektroskopija

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Reduction of Ni release and improvement of the friction behaviour of NiTi orthodontic archwires by oxidation treatments

Cited by 34 publications

References 31 publications

In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires

In vitro biocompatibility of nickel-titanium esthetic orthodontic archwires

Martensitic Transformation and Superelastic Properties of Ti-Nb Base Alloys

Selective leaching and surface properties of TiNiFe shape-memory alloys

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