română D. RENTERÍA-ZAMARRÓN , J. A. DÍAZ-GUILLÉN, D. A. CORTÉS-HERNÁNDEZ, S. M. MONTEMAYOR, C. M. LÓPEZ–BADILLO, J.C. DÍAZ-GUILLÉN , A. F. FUENTES
Abstract
A biomimetic method was used to improve bioactivity of Sr2SiO4. Strontium silicate was obtained by using a combination of techniques such as mechanical activation and reactive sintering, of a powder mixture of strontium carbonate and silicon dioxide. Single phase Sr2SiO4 was obtained after 6 h of mechanical milling of the starting reagents, followed by a uniaxial pressing and a thermal treatment in air at 1200 °C for 6 h. For the biomimetic treatment, samples were immersed in a simulated body fluid (SBF) for 7, 14 and 21 days on a bed of wollastonite powder and were characterized by SEM, EDS, XRD, FT-IR and TEM. For comparison purposes, experiments were also performed without using the bioactive powder bed. Results showed that a bone-like apatite layer was formed on strontium silicate after 21 days of immersion in SBF without a bed of wollastonite and slight layer of Ca, P-rich compound, using a bed of wollastonite powder, corroborating the viability of these oxides to be used as bioactive materials.
Keywords
Strontium silicate, Biomimetic method, Wollastonite, Mechanical activation, Reactive sintering
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Year
2020
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Issue
50 (1)
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Pages
10-16
DOREL RADU, OVIDIU DUMITRESCU
Abstract
Biomaterials, which are increasingly used in the field of restorative medicine, may represent vitreous, glass-ceramic or ceramic systems, all of which have one common feature: bioactivity. The acid-basic character of the interactions at the interface organic material - inorganic material (implant) determines the acceptance speed and life duration of the implant.
As a result, there is a strong correlation between basicity and bioactivity, which must be expressed quantitatively. Therefore, in this paper it is emphasized that the bioactivity of silicate glasses is closely correlated with the basicity percentage, pB.
Based upon a mathematical model of optimal programming, the limits of pB were determined, between which the biocompatibility for the glasses from the complex silicate systems highlighted: pB = 60 ÷ 70%, a result compared and confirmed by a series of data from specialized literature.
Keywords
silicate bioglass, basicity, oxide composition – basicity - bioactivity
RADU MIREA, LAURENȚIU CEATRA, ANDREI TIBERIU CUCURUZ, RĂZVAN ENE, ELISA POPESCU, IULIANA BIRIȘ, MIHAIELLA CREȚU
Abstract
The paper aims to present the investigation of metallic biomaterials by using state of the art investigation techniques and instruments in order to assess their degradation after they have been used as implants. Thus, several metallic biomaterials used for different periods of time by different patients were collected and analysed by functional and structural point of view, meaning that mechanical properties will be determined and the functionality of the metallic biomaterials will be assessed and structural point of view. Metallic biomaterials consisted of: one dental Cr-Co based material used for 6 months, one dental Ni-Cr based material used for 5 years and one Fe-Cr based orthopaedic screw used for 3 months. It is to be mentioned that the exact composition of the biomaterials before they were used as implants was unknown. The functional investigation of the metallic biomaterials consisted of hardness measurements by using a Vickers micro hardness tester, the structural investigation of the materials consisted of light and electronic microscopy by using an FEI INSPECT F electronic microscope coupled with X-Ray diffraction EDAX type and composition determination by using an ICP-MS spectrometer.
Keywords
metallic biomaterials, hardness, mass spectroscopy, light microscopy, electronic microscopy
ANDREEA-IOANA ZAMFIRESCU, ADELA BANCIU, DANIEL BANCIU, SORIN-ION JINGA, CRISTINA BUSUIOC
Abstract
This work aims the obtaining of composite scaffolds based on polycaprolactone fibres loaded with inorganic powders, hydroxyapatite or/and barium titanate, through the electrospinning technique, as well as their characterization both from physicochemical point of view and biological side in order to establish the potential of such materials for integration in bone regeneration applications. The results confirmed the achievement of the designed materials, with a relative homogenous distribution of the mineral phases onto or inside the fibrous structures, together with a good response as respects the behaviour of fibroblast cells cultured in the presence of these multifunctional scaffolds with biocompatible, bioresorbable and bioactive features, combined with external stimulation capabilities (electric or/and magnetic).
Keywords
Polycaprolactone; Hydroxyapatite; Barium titanate; Composite scaffolds; Electrospinning
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Year
2020
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Issue
50 (2)
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Pages
161-165
ANTOANELA COVACI, LUCIAN TOMA CIOCAN , SILVIU MIREL PIŢURU, IOAN PLOTOG, GAUDENŢIU VĂRZARU, MIHNEA IOAN NICOLESCU, CRISTIAN FUNIERU, ANDREEA CRISTINA DIDILESCU
Abstract
This in vitro study aimed to evaluate and compare the dentine adhesion of two modern pulp capping materials: TheraCal LC (Bisco Inc. U.S.A.) and BioMTA (Cerkamed Poland). The samples have been prepared simulating in vivo conditions, in accordance with ISO/DIN standard protocols for this type of test. Twelve samples were prepared in this way, being preserved in good condition for each material in order to be investigated and the results interpretated. The values of the shear test, measured in kgf for each sample, have been recorded. A paired t-test was conducted to compare mean adhesion results in TheraCal and MTA groups. The results of our study showed a statistical significant difference between the measurements for TheraCal (M=1.27, SD=0.69) and MTA (M=0.22, SD=0.13); t(11)=4.80, p=0.0005. The results suggest that TheraCal has better adhesion properties than MTA.
Keywords
dentine, pulp capping materials, adhesion, shear test