Papers by Author: D. Iordachescu

Abstract: The aim of this paper is to correlate surface features of degraded temporary teeth from area with high pollution with the cell adhesion and proliferation. Viability of gingival fibroblast (HGF-1, CRL-2014, American Type Culture Collection) was evaluated with a MTT (3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromide ) test and the values are discussed for the most degraded temporary teeth in correlation with the change in surface morphology and hydrophilic/hydrophobic balance, taking into account that cell adhesion is related to a more hydrophilic character.

Abstract: Many researchers have assumed that a combination of hydroxyl apatite (HAP) and collagen (COL) may be the best solution for bone replacement and have prepared their composites by several techniques [1]. However, such HAP/COL composite had no nanostructure similar to bone, and consequently indicated no bone-like mechanical properties. These results demonstrate that the chemical composition similar to bone only is insufficient for bone metabolism and mechanical properties. Mechanical and biological performance of this type of materials could be improved by adding TiO2 within the initial mixture of nanostructured composites [2]. Ternary nanostructured systems consisting of hydroxyl apatite, TiO2 aerogel and collagen were prepared for the first time by hydrothermal procedure in high pressure conditions. Among many advantages, the synthesis method proposed in this paper could lead to formation of chemically bonded compounds as a consequence of high pressure conditions. The resulted material could find applications in bone tissue regenerative medicine, either in powder form for bone defects treatment, or in matrix form as osteoconductive coating for metal implants. Further studies are necessary to evaluate the osteoconductive properties.

Abstract: The present work is focused on the stability of bioactivated CoCr alloy in biological environment (buffered saline solution (PBS), lactic acid, citric acid). The chemical and electrochemical deposition was characterized by electrochemical methods (open circuit potential, cyclic voltametry), scanning electronic microscope (SEM), x-ray diffractometer (XRD), inductively coupled plasma/mass spectrometry (ICP/MS) and citotoxicity test. The results prove a good electrochemical stability in all cases.