Cristina Dumitriu

Dr. Cristina Dumitriu


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 May 2019 in Materials
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Journal Article
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GVGeorgeta Voicu
Georgeta Voicu
Andreea DidilescuAndreea Didilescu
Andreea Didilescu
ASAndrei Bogdan Stoian
Andrei Bogdan Stoian
CDCristina Dumitriu
Cristina Dumitriu
Maria GreabuMaria Greabu
Maria Greabu
MAMihai Andrei
Mihai Andrei
This paper aims to investigate the composition, surface, and microstructural characteristics, and bioactivity of two commercially available pulp capping materials known as TheraCal LC and BIO MTA+. The materials were prepared as cylindrical samples and assessed by X-ray diffraction (XRD) and complex thermal analysis for mineralogical characterization, and by scanning electron microscopy (SEM) coupled with energy dispersive of X-ray (EDX), Fourier-Transformed Infrared Spectroscopy (FT-IR), and atomic force microscopy (AFM) for microstructural and surface characteristics. The in vitro bioactivity was highlighted by surface mineralization throughout SEM coupled with EDX and FT-IR analysis. XRD analysis performed on both materials showed calcium silicate phases and different radiopacifying compounds. AFM measurements indicated a smoother and more homogenous surface with a lower average roughness for TheraCal LC due to the resin matrix from its composition. FT-IR analysis displayed bands for several compounds in both materials. Both materials exhibited bioactive properties showing surface mineralization after being immersed in solution similar to the human physiological environment. However, the MTA cement showed a better mineralization due to the anhydrous and hydrated phases.

19 December 2024 in Applied Sciences
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Cristian PirvuCristian Pirvu
Cristian Pirvu
Mariana ProdanaMariana Prodana
Mariana Prodana
CDCristina Dumitriu
Cristina Dumitriu
AGAlexsndru George Gheboianu
Alexsndru George Gheboianu
Andreea Madalina PandeleAndreea Madalina Pandele
Andreea Madalina Pandele
GBGeorge-Octavian Buica
George-Octavian Buica
TiO2 nanotubes and self-reduced TiO2 nanotube semiconductor electrodes were used for electrochemical metal ion detection in an open circuit under photo-accumulation conditions. Due to their surface properties, the electrodes showed different responses towards metal ions at different wavelengths of light radiation. Using TiO2 nanotube-based electrodes, Pb(II) and Cu(II) ions were detected at irradiation wavelengths of 389 nm and 426 nm. Detection limits of 8 × 10−9 M and 5 × 10−9 M for Pb(II) and 3 × 10−8 and 7 × 10−9 M for Cu(II) were obtained at the two wavelengths, respectively. The self-reducing electrode showed a response to Pb(II) and Cu(II) ions when irradiated with light at 389 nm, while at 426 nm, Hg(II) ions along with Pb(II) and Cu(II) ions were detected. The obtained detection limits with self-reduced TiO2 nanotube electrodes for Pb(II) and Cu(II) at 389 nm were 2 × 10−7 M and 8 × 10−9 M, respectively. At a wavelength of 426 nm, the detection limits were 1 × 10−7 M, 3 × 10−9, and 4 × 10−9 M for Pb(II), Cu(II), and Hg(II), respectively.

13 January 2025 in Biosensors
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APAngela Păun
Angela Păun
SPSimona Popescu
Simona Popescu
AUAlisa Ioana Ungureanu
Alisa Ioana Ungureanu
RTRoxana Trușcă
Roxana Trușcă
APAlina Popp
Alina Popp
GBGeorge-Octavian Buica
George-Octavian Buica
A novel electrochemical detection method utilizing a cost-effective hybrid-modified electrode has been established. A glassy carbon (GC) modified electrode was tested for its ability to measure electrochemical tTG antibody levels, which are essential for diagnosing and monitoring Celiac disease (CD). Tissue transglutaminase protein biomolecules are immobilized on a quantum dots-polypyrrole nanocomposite in the improved electrode. Initial, quantum dots (QDs) were obtained from Bombyx mori silk fibroin and embedded in polypyrrole film. Using carbodiimide coupling, a polyamidoamine (PAMAM) dendrimer was linked with GQDs-polypyrrole film to improve sensor sensitivity. The tissue transglutaminase (tTG) antigen was cross-linked onto PAMAM using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC)-N-hydroxy succinimide (NHS) chemistry to develop a nanoprobe that can detect human serum anti-tTG antibodies. The physicochemical characteristics of the synthesized nanocomposite were examined by FTIR, UV-visible, FE-SEM, EDX, and electrochemical studies. The novel electrode measures anti-tissue antibody levels in real time using human blood serum samples. The modified electrode has great repeatability and an 8.7 U/mL detection limit. Serum samples from healthy people and CD patients were compared to standard ELISA kit assays. SPSS and Excel were used for statistical analysis. The improved electrode and detection system can identify anti-tissue antibodies up to 80 U/mL.

17 December 2023 in Crystals
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Journal Article
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APAngela Păun
Angela Păun
VPValeria Luciana Florina Petrina
Valeria Luciana Florina Petrina
Nicoleta BadeaNicoleta Badea
Nicoleta Badea
Camelia UngureanuCamelia Ungureanu
Camelia Ungureanu
SPSimona Popescu
Simona Popescu
CDCristina Dumitriu
Cristina Dumitriu
The early loss of dental implants can be avoided with systemic antibiotics, however there are potentially significant side effects. Consequently, the use of local drug administration techniques is necessary to make dental implant therapy more practical. In this study, Y-branched nanotubes were prepared by non-expensive and simple anodization in two steps. Tests were performed to highlight their potential for local antibiotic administration. Y-branched nanotubes were able to incorporate a dose of Tetracycline and ensure its electrochemical stability. The presence of tetracycline significantly enhanced antibacterial efficacy, resulting in an increase of up to 55% for Escherichia coli and Pseudomonas aeruginosa and 50% for Staphylococcus aureus. The comparable antibacterial effects of the nanostructured surfaces highlight the potential of tetracycline in promoting antimicrobial action. Moreover, the addition of tetracycline does not influence the structural, morphological and stability properties of the nanostructured deposited TiO2 films.