Browsing by Author "Avinashi S.K."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Fabrication of bioactive transparent glass ceramics 55SiO2�25Na2O-(15-x)CaO�5P2O5- xZrO2 (0?x?6): Physical, structural and in vitro cell viability insights for biomedical applications
    (Elsevier Ltd, 2024) Shweta; Mishra R.K.; Pradhan B.L.; Parveen S.; Behera P.; Avinashi S.K.; Kumari S.; Fatima Z.; Sen P.; Kumar S.; Mishra M.; Banerjee M.; Dey K.K.; Ghosh M.; Gautam C.
    Zirconia (ZrO2) reinforced transparent glass ceramics (TGCs) are excellent materials for enhanced cell viability and biocompatibility for biomedical applications. Herein, ZrO2 doped SiO2�Na2O�CaO�P2O5 base compositions derived from traditional melt-quench technique. The impacts of ZrO2 on the physical, structural, optical, morphological, and biological evaluation were studied. XRD discloses the major phase formation of buchwaldite (CaNaPO4) and disodium calcium silicate (Na2CaSiO4). Density of the TGC samples was calculated and found to be in the range of 2.535�2.910 g/cm3. The optical parameters, and particle size were estimated and analyzed. Herein, ZrO2 plays a significant role as a network modifier and various bond assignments in the glassy network that confirmed by FTIR spectroscopy. Surface morphology and its elemental investigations were also studied using SEM and XPS techniques. Solid state NMR spectrum on 23Na, 29Si, and 31P nucleus were studied for various interactions. Moreover, the cell viability of the fabricated samples on the cancer cells were analyzed and resulted to possess the half maximum inhibitory concentrations (IC50) of the samples were calculated and valued to be 92 to 40 ?g/ml respectively. The sample 55SiO2�25Na2O�9CaO�5P2O5�6ZrO2 (BG4) demonstrated a remarkable biological activity for bone regeneration and implants. Further, the cell cytotoxicity was evaluated by performing trypan blue assay, DAPI and DCFH-DA staining on the TGC samples. The data assembled in this research approves the hypothesis that the TGCs represent a feasible material for the biomedical applications for bone and tooth implants. � 2024 Elsevier Ltd and Techna Group S.r.l.
  • Thumbnail Image
    Item
    Fabrication, structural, and enhanced mechanical behavior of MgO substituted PMMA composites for dental applications
    (Nature Research, 2024) Kumari S.; Mishra R.K.; Parveen S.; Avinashi S.K.; Hussain A.; Kumar S.; Banerjee M.; Rao J.; Kumar R.; Gautam R.K.; Gautam C.
    The most common denture material used for dentistry is poly-methyl-methacrylate (PMMA). Usually, the polymeric PMMA material has numerous biological, mechanical and cost-effective shortcomings. Hence, to resolve such types of drawbacks, attempts have been made to investigate fillers of the PMMA like alumina (Al2O3), silica (SiO2), zirconia (ZrO2) etc. For the enhancement of the PMMA properties a suitable additive is required for its orthopedic applications. Herein, the main motive of this study was to synthesize a magnesium oxide (MgO) reinforced polymer-based hybrid nano-composites by using heat cure method with superior optical, biological and mechanical characteristics. For the structural and vibrational studies of the composites, XRD and FT-IR were carried out. Herein, the percentage of crystallinity for all the fabricated composites were also calculated and found to be 14.79�30.31. Various physical and optical parameters such as density, band gap, Urbach energy, cutoff energy, cutoff wavelength, steepness parameter, electron�phonon interaction, refractive index, and optical dielectric constant were also studied and their values are found to be in the range of 1.21�1.394�g/cm3, 5.44�5.48�eV, 0.167�0.027�eV, 5.68�eV, 218�nm, 0.156�0.962, 4.273�0.693, 1.937�1.932, and 3.752�3.731 respectively. To evaluate the mechanical properties like compressive strength, flexural strength, and fracture toughness of the composites a Universal Testing Machine (UTM) was used and their values were�60.3 and 101�MPa, 78 and 40.3�MPa, 5.85 and 9.8�MPa-m1/2 respectively. Tribological tests of the composites were also carried out. In order to check the toxicity, MTT assay was also carried out for the PM0 and PM15 [(x)MgO + (100 ? x) (C5O2H8)n] (x = 0 and 15) composites. This study provides a comprehensive insight into the structural, physical, optical, and biological features of the fabricated PMMA-MgO composites, highlighting the potential of the PM15 composite with its enhanced density, mechanical strength, and excellent biocompatibility for denture applications. � 2024, The Author(s).
  • Thumbnail Image
    Item
    Synergetic impact of MgO on PMMA-ZrO2 hybrid composites: Evaluation of structural, morphological and improved mechanical behavior for dental applications
    (Elsevier Inc., 2024) Kumari S.; Verma A.; Mishra R.K.; Avinashi S.K.; Shweta; Singh S.; Behera P.; Rao J.; Gautam R.K.; Pradhan B.L.; Dey K.K.; Ghosh M.; Mishra M.; Gautam C.
    This work aims to demonstrate the effect of ZrO2 and MgO inclusion into the Poly(methyl methacrylate) (PMMA). To fabricate novel hybrid composites via heat cure method, various composites (PZM2, PZM4 and PZM6) were synthesized in the system [(95-x) PMMA + 5 ZrO2 + x MgO] (x = 2, 4, and 6) respectively. Density of the prepared composites were determined and varying between 1.035�1.152 g/cm3. X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) followed by EDAX and mechanical testing were performed to evaluate the fabricated composite properties. Moreover, to explore the structure of the fabricated composites the 13 C CP-MAS SSNMR and 1 H-13 C Phase-Modulated Lee Goldberg (PMLG) HETCOR Spectrum were recorded which clarify chemical shifting and motional dynamics of the composites. Mechanical tests were performed by UTM and the obtained parameters such as compressive strength, Young's modulus, fracture toughness, brittleness coefficient, flexural strength and flexural modulus are found to be in the range of 91�100 MPa, 0.48�0.51 GPa, 9.122�9.705 MPa.m1/2, 0.66�0.815, 51.03�42.78 MPa and 499�663 MPa respectively. Some more mechanical parameters such as proportional limit, elastic limit, failure strength, modulus of resilience and modulus of toughness were also calculated. Furthermore, tribological properties were also determined and the coefficient of friction (COF) was decreased by 17.4 % and 38 % for composite PZM6 at 20 N and 40 N as compared to the composite PZM2 and the lowest wear volume of 1.55 mm3 was observed for PZM2, whereas the maximum volume loss of 5.64 mm3 is observed for composite PZM6. To check out the biocompatibility, cytotoxicity and genotoxicity of the fabricated composites the Trypan-blue assay was also performed for PZM2 and PZM6 composites. Dissection on the gut of larvae was also performed on the both composites followed by DAPI and DCFH-DA staining. Therefore, these synthesized samples can be used for the fabrication of denture materials. � 2024 Elsevier Inc.
  • Thumbnail Image
    Item
    Synergistic doping effect of La2O3 on BaO-TiO2-SiO2 glass-ceramics: Evolution of physical, structural, morphological, and dielectric behaviour for electronics applications
    (Elsevier Ltd, 2024) Mishra R.K.; Avinashi S.K.; Kumari S.; Shweta; Nain R.; Katheriya T.; Dwivedi R.K.; Upadhyay S.; Gautam C.
    Herein, numerous investigations such as structural, physical, morphological, optical, and dielectric properties of BaO-TiO2-SiO2 glass-ceramics (GCs) doped with La2O3 were carried out. Various glasses were synthesized within a glass system [(30-x)BaO.30TiO2.40SiO2].x[La2O3], (x=0,2,4, and 6 mol% of La2O3) using a conventional melt-quench method. XRD confirmed the amorphous nature of the glass samples. Differential scanning calorimetry (DSC) was used to identify the glass transition (Tg) and crystallization temperatures (Tc) of the samples. Further, controlled heat treatment of the glasses led to the fabrication of glass-ceramics and their XRD analysis revealed polycrystalline structure, predominantly consisting of a major phase of tetragonal Fresnoite (Ba2TiO8Si2). Furthermore, with the addition of La2O3, the prepared GCs exhibited improved physical properties, including an increase in density (3.783�4.611 g/cm3) and oxygen packing density (81.177�92.303 g-atom/l). Additionally, to study the bonding and structural characteristics, FTIR and Raman spectroscopies were conducted. In order to study the optical properties, UV�visible spectroscopy was executed and showed a reduced indirect energy band gap from 4.290 to 4.220 eV with increasing La2O3. To study the morphological behaviour, SEM and TEM were performed. Eventually, to examine the dielectric characteristics, relative dielectric constant (?r) and dielectric loss (Tan ?) over the glass-ceramics was conducted using a �Novocontrol Impedance Analyzer�. The ?r and Tan ? values exhibited temperature-dependent behaviour and found to be increased within the frequency range of 1 kHz to 1 MHz. The BTSLC6 glass-ceramic, (24BaO.30TiO2.40SiO2.6La2O3), exhibited a high dielectric constant of ? 9335 and a low dielectric loss of 0.52 at 1 kHz, mainly due to space charge polarization. This makes it a promising candidate for applications in multilayer ceramic capacitors, energy storage, photonics, and electronics. � 2024 Elsevier B.V.