TY  - JOUR
AU  - Lepojević, Nikola
AU  - Šćepan, Ivana
AU  - Glišić, Branislav
AU  - Jenko, Monika
AU  - Godec, Matjaz
AU  - Hocevar, Samo
AU  - Rudolf, Rebeka
PY  - 2019
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2375
AB  - Nickel-titanium (NiTi) orthodontic archwires are crucial in the initial stages of orthodontic therapy when the movement of teeth and deflection of the archwire are the largest. Their great mechanical properties come with their main disadvantage-the leakage of nickel. Various in vitro studies measured nickel leakage from archwires that were only immersed in the medium with little or minimal simulation of all stress and deflection forces that affect them. This study aims to overcome that by simulating deflection forces that those archwires are exposed to inside the mouth of a patient. NiTi orthodontic archwires were immersed in CACO2-2 cell culture medium and then immediately loaded while using a simulator of multiaxial stress for 24 h. After the experiment, the surface of the NiTi orthodontic archwires were analysed while using scanning electron microscopy (SEM) and auger electron spectroscopy (AES). The observations showed significant microstructural and compositional changes within the first 51 nm thickness of the archwire surface. Furthermore, the released nickel and titanium concentrations in the CACO2-2 cell culture medium were measured while using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). It was found out that the level of released nickel ions was 1.310 mu g/L, which can be assigned as statistically significant results. These data represent the first mention of the already detectable release of Ni ions after 24 h during the simulation of mechanical loading in the CACO2-2 cell culture medium, which is important for clinical orthodontic praxis.
PB  - Mdpi, Basel
T2  - Coatings
T1  - Characterisation of NiTi Orthodontic Archwires Surface after the Simulation of Mechanical Loading in CACO2-2 Cell Culture
VL  - 9
IS  - 7
DO  - 10.3390/coatings9070440
ER  - 

@article{
author = "Lepojević, Nikola and Šćepan, Ivana and Glišić, Branislav and Jenko, Monika and Godec, Matjaz and Hocevar, Samo and Rudolf, Rebeka",
year = "2019",
abstract = "Nickel-titanium (NiTi) orthodontic archwires are crucial in the initial stages of orthodontic therapy when the movement of teeth and deflection of the archwire are the largest. Their great mechanical properties come with their main disadvantage-the leakage of nickel. Various in vitro studies measured nickel leakage from archwires that were only immersed in the medium with little or minimal simulation of all stress and deflection forces that affect them. This study aims to overcome that by simulating deflection forces that those archwires are exposed to inside the mouth of a patient. NiTi orthodontic archwires were immersed in CACO2-2 cell culture medium and then immediately loaded while using a simulator of multiaxial stress for 24 h. After the experiment, the surface of the NiTi orthodontic archwires were analysed while using scanning electron microscopy (SEM) and auger electron spectroscopy (AES). The observations showed significant microstructural and compositional changes within the first 51 nm thickness of the archwire surface. Furthermore, the released nickel and titanium concentrations in the CACO2-2 cell culture medium were measured while using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). It was found out that the level of released nickel ions was 1.310 mu g/L, which can be assigned as statistically significant results. These data represent the first mention of the already detectable release of Ni ions after 24 h during the simulation of mechanical loading in the CACO2-2 cell culture medium, which is important for clinical orthodontic praxis.",
publisher = "Mdpi, Basel",
journal = "Coatings",
title = "Characterisation of NiTi Orthodontic Archwires Surface after the Simulation of Mechanical Loading in CACO2-2 Cell Culture",
volume = "9",
number = "7",
doi = "10.3390/coatings9070440"
}

Lepojević, N., Šćepan, I., Glišić, B., Jenko, M., Godec, M., Hocevar, S.,& Rudolf, R.. (2019). Characterisation of NiTi Orthodontic Archwires Surface after the Simulation of Mechanical Loading in CACO2-2 Cell Culture. in Coatings
Mdpi, Basel., 9(7).
https://doi.org/10.3390/coatings9070440

Lepojević N, Šćepan I, Glišić B, Jenko M, Godec M, Hocevar S, Rudolf R. Characterisation of NiTi Orthodontic Archwires Surface after the Simulation of Mechanical Loading in CACO2-2 Cell Culture. in Coatings. 2019;9(7).
doi:10.3390/coatings9070440 .

Lepojević, Nikola, Šćepan, Ivana, Glišić, Branislav, Jenko, Monika, Godec, Matjaz, Hocevar, Samo, Rudolf, Rebeka, "Characterisation of NiTi Orthodontic Archwires Surface after the Simulation of Mechanical Loading in CACO2-2 Cell Culture" in Coatings, 9, no. 7 (2019),
https://doi.org/10.3390/coatings9070440 . .

TY  - JOUR
AU  - Rudolf, Rebeka
AU  - Stamenković, Dragoslav
AU  - Aleksić, Zoran
AU  - Jenko, Monika
AU  - Đorđević, Igor
AU  - Todorović, Aleksandar
AU  - Jokanović, Vukoman
AU  - Raić, Karlo T.
PY  - 2015
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1982
AB  - Thin hydroxyapatite coatings were produced on Cp-Titanium Grade-2 samples, with new high-voltage pulse-power equipment PJ-100 (Plasma Jet, Serbia) in order to get a more stable implant structure appropriate for further clinical applications. A comparative analysis of differently prepared surfaces of the Cp-Titanium Grade-2 samples was done before the hydroxyapatite was applied. Microstructural observation of the modified hydroxyapatite/implant surface was done using scanning-electron-microscopy imaging and Auger electron spectroscopy, with the aim of detecting the morphology and the elements contained in the new surfaces of the samples. The results confirmed that the surface of Cp-Titanium Grade-2 modified with hydroxyapatite is very similar to the bone structure.
PB  - Inst Za Kovinske Materiale I In Tehnologie, Ljubjana
T2  - Materiali in Tehnologije
T1  - Hydroxyapatite coatings on cp-titanium grade-2 surfaces prepared with plasma spraying
VL  - 49
IS  - 1
SP  - 81
EP  - 86
UR  - https://hdl.handle.net/21.15107/rcub_vinar_427
ER  - 

@article{
author = "Rudolf, Rebeka and Stamenković, Dragoslav and Aleksić, Zoran and Jenko, Monika and Đorđević, Igor and Todorović, Aleksandar and Jokanović, Vukoman and Raić, Karlo T.",
year = "2015",
abstract = "Thin hydroxyapatite coatings were produced on Cp-Titanium Grade-2 samples, with new high-voltage pulse-power equipment PJ-100 (Plasma Jet, Serbia) in order to get a more stable implant structure appropriate for further clinical applications. A comparative analysis of differently prepared surfaces of the Cp-Titanium Grade-2 samples was done before the hydroxyapatite was applied. Microstructural observation of the modified hydroxyapatite/implant surface was done using scanning-electron-microscopy imaging and Auger electron spectroscopy, with the aim of detecting the morphology and the elements contained in the new surfaces of the samples. The results confirmed that the surface of Cp-Titanium Grade-2 modified with hydroxyapatite is very similar to the bone structure.",
publisher = "Inst Za Kovinske Materiale I In Tehnologie, Ljubjana",
journal = "Materiali in Tehnologije",
title = "Hydroxyapatite coatings on cp-titanium grade-2 surfaces prepared with plasma spraying",
volume = "49",
number = "1",
pages = "81-86",
url = "https://hdl.handle.net/21.15107/rcub_vinar_427"
}

Rudolf, R., Stamenković, D., Aleksić, Z., Jenko, M., Đorđević, I., Todorović, A., Jokanović, V.,& Raić, K. T.. (2015). Hydroxyapatite coatings on cp-titanium grade-2 surfaces prepared with plasma spraying. in Materiali in Tehnologije
Inst Za Kovinske Materiale I In Tehnologie, Ljubjana., 49(1), 81-86.
https://hdl.handle.net/21.15107/rcub_vinar_427

Rudolf R, Stamenković D, Aleksić Z, Jenko M, Đorđević I, Todorović A, Jokanović V, Raić KT. Hydroxyapatite coatings on cp-titanium grade-2 surfaces prepared with plasma spraying. in Materiali in Tehnologije. 2015;49(1):81-86.
https://hdl.handle.net/21.15107/rcub_vinar_427 .

Rudolf, Rebeka, Stamenković, Dragoslav, Aleksić, Zoran, Jenko, Monika, Đorđević, Igor, Todorović, Aleksandar, Jokanović, Vukoman, Raić, Karlo T., "Hydroxyapatite coatings on cp-titanium grade-2 surfaces prepared with plasma spraying" in Materiali in Tehnologije, 49, no. 1 (2015):81-86,
https://hdl.handle.net/21.15107/rcub_vinar_427 .

TY  - JOUR
AU  - Jokanović, Vukoman
AU  - Vilotijević, Miroljub
AU  - Jokanović, Bojan
AU  - Jenko, Monika
AU  - Anžel, Ivan
AU  - Stamenković, Dragoslav
AU  - Lazić, Vojkan
AU  - Rudolf, Rebeka
PY  - 2014
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1954
AB  - In this research, the structure changes along the depth gradient layers of titanium substrate, after etching with NaOH and subsequent thermal treatment at various temperatures between 300 and 800 degrees C, were investigated by XRD, FTIR and AES. Particularly, the changes of Ti substrate after etching with NaOH, subsequent ionic exchange of Na+ with Ca2+ ions and thermal treatment at 700 degrees C were analysed. Due to this approach, it was possible to get insight into the chemical changes and changes of Ti oxidation states and consequent phase analysis, along the depth of the titanium oxide coatings. In addition, Secondary Electron Imaging (SEI) showed very interesting nanotopology of all samples. Particularly interesting topology, consisting of very thin nano-designed walls between mutually interconnected pores, was observed for the sample in which Na+ were replaced with Ca2+ ions. This structure might be suitable for deposition of hydroxyapatite by biomimetic or plasma methods and as an appropriate scaffold for cell adhesion and proliferation.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Corrosion Science
T1  - Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment
VL  - 82
SP  - 180
EP  - 190
DO  - 10.1016/j.corsci.2014.01.014
ER  - 

@article{
author = "Jokanović, Vukoman and Vilotijević, Miroljub and Jokanović, Bojan and Jenko, Monika and Anžel, Ivan and Stamenković, Dragoslav and Lazić, Vojkan and Rudolf, Rebeka",
year = "2014",
abstract = "In this research, the structure changes along the depth gradient layers of titanium substrate, after etching with NaOH and subsequent thermal treatment at various temperatures between 300 and 800 degrees C, were investigated by XRD, FTIR and AES. Particularly, the changes of Ti substrate after etching with NaOH, subsequent ionic exchange of Na+ with Ca2+ ions and thermal treatment at 700 degrees C were analysed. Due to this approach, it was possible to get insight into the chemical changes and changes of Ti oxidation states and consequent phase analysis, along the depth of the titanium oxide coatings. In addition, Secondary Electron Imaging (SEI) showed very interesting nanotopology of all samples. Particularly interesting topology, consisting of very thin nano-designed walls between mutually interconnected pores, was observed for the sample in which Na+ were replaced with Ca2+ ions. This structure might be suitable for deposition of hydroxyapatite by biomimetic or plasma methods and as an appropriate scaffold for cell adhesion and proliferation.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Corrosion Science",
title = "Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment",
volume = "82",
pages = "180-190",
doi = "10.1016/j.corsci.2014.01.014"
}

Jokanović, V., Vilotijević, M., Jokanović, B., Jenko, M., Anžel, I., Stamenković, D., Lazić, V.,& Rudolf, R.. (2014). Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment. in Corrosion Science
Pergamon-Elsevier Science Ltd, Oxford., 82, 180-190.
https://doi.org/10.1016/j.corsci.2014.01.014

Jokanović V, Vilotijević M, Jokanović B, Jenko M, Anžel I, Stamenković D, Lazić V, Rudolf R. Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment. in Corrosion Science. 2014;82:180-190.
doi:10.1016/j.corsci.2014.01.014 .

Jokanović, Vukoman, Vilotijević, Miroljub, Jokanović, Bojan, Jenko, Monika, Anžel, Ivan, Stamenković, Dragoslav, Lazić, Vojkan, Rudolf, Rebeka, "Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment" in Corrosion Science, 82 (2014):180-190,
https://doi.org/10.1016/j.corsci.2014.01.014 . .

TY  - JOUR
AU  - Čolić, Miodrag
AU  - Rudolf, Rebeka
AU  - Stamenković, Dragoslav
AU  - Anžel, Ivan
AU  - Vucević, Dragana
AU  - Jenko, Monika
AU  - Lazić, Vojkan
AU  - Lojen, Gorazd
PY  - 2010
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1553
AB  - Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.
PB  - Elsevier Sci Ltd, Oxford
T2  - Acta Biomaterialia
T1  - Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy
VL  - 6
IS  - 1
SP  - 308
EP  - 317
DO  - 10.1016/j.actbio.2009.06.027
ER  - 

@article{
author = "Čolić, Miodrag and Rudolf, Rebeka and Stamenković, Dragoslav and Anžel, Ivan and Vucević, Dragana and Jenko, Monika and Lazić, Vojkan and Lojen, Gorazd",
year = "2010",
abstract = "Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Acta Biomaterialia",
title = "Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy",
volume = "6",
number = "1",
pages = "308-317",
doi = "10.1016/j.actbio.2009.06.027"
}

Čolić, M., Rudolf, R., Stamenković, D., Anžel, I., Vucević, D., Jenko, M., Lazić, V.,& Lojen, G.. (2010). Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy. in Acta Biomaterialia
Elsevier Sci Ltd, Oxford., 6(1), 308-317.
https://doi.org/10.1016/j.actbio.2009.06.027

Čolić M, Rudolf R, Stamenković D, Anžel I, Vucević D, Jenko M, Lazić V, Lojen G. Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy. in Acta Biomaterialia. 2010;6(1):308-317.
doi:10.1016/j.actbio.2009.06.027 .

Čolić, Miodrag, Rudolf, Rebeka, Stamenković, Dragoslav, Anžel, Ivan, Vucević, Dragana, Jenko, Monika, Lazić, Vojkan, Lojen, Gorazd, "Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy" in Acta Biomaterialia, 6, no. 1 (2010):308-317,
https://doi.org/10.1016/j.actbio.2009.06.027 . .