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Soft reliner and glaze are materials used over full or partial dental prosthesis to prevent excessive pressure on the supporting tissues. They are also indicated as supportive treatment for dental stomatitis, especially when modified by the addition of medications. The objective of the work was to evaluate the antimicrobial effect of silver-coated silica nanoparticles in a glaze and a soft reliner. The nanoparticles were synthesized, characterized, and tested by minimum inhibitory concentration (MIC) for C. albicans SC5314. Then, the nanoparticles were incorporated to a glaze and a soft reliner, which were called nanocomposites. Then, the nanocomposites were divided into six groups (n = 12): CG: glaze/reliner; CR: reliner; G1: glaze + 1% nanoparticles/reliner; G2: glaze + 2.5% nanoparticles/reliner; R1: reliner + 1%; R2: reliner + 2.5%. The nanocomposites were characterized by a goniometer and by a scanning electron microscope. The antibiofilm test was performed against C. albicans SC5314. According to the MIC results, the non-functionalized nanoparticles reduced fungal growth at 1000 μg/mL and the functionalized nanoparticles at 2000 μg/mL. The functionalized nanoparticle had a superior dispersion being selected for the antibiofilm test. There was a reduction of 64% in CFU/specimen count for the glaze, not statistically significant (p = 0.244). For the soft reliner, there was an increase in CFU/specimen with the presence of nanoparticles, still not statistically significant (p = 0.264). In conclusion, it is necessary to conduct new studies to increase the release of silver, thus improving nanoparticles' antifungal potential. [ABSTRACT FROM AUTHOR]

The phase of crystalline α-wollastonite (α-CaSiO 3) powders was prepared at low temperature via sol gel method. The formation mechanisms of α-wollastonite (α-CaSiO 3) using different calcium salts were examined. The synthesis was carried out in absence of organic solvents, using as starting materials silicic acid and inorganic salts (CaCl 2.H 2 O and Ca(NO 3) 2.4H 2 O). The samples were analyzed by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetry/Differential Scanning Calorimetry (TGA-DSC), X-Ray Diffraction (XRD) and Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). The experimental results demonstrate that the calcium source strongly influences the characteristics of the resultant powders, as phase purity and morphology of the wollastonite particles. XRD analysis showed that, using CaCl 2.H 2 O on the synthesis, α-wollastonite started to crystallize as majority phase at 700 °C. The complete crystallization of α-wollastonite was observed after the calcination at 1000 °C for 5 h, while samples prepared with Ca(NO 3) 2.4H 2 O, only crystallized α-wollastonite at 1200 °C. This difference in crystallization temperature is probably related to the higher homogeneity and the elevated number of Si–O–Ca bonds present in samples prepared with CaCl 2.H 2 O. [ABSTRACT FROM AUTHOR]

Life expectancy has been growing, and more people are developing bone diseases such as arthritis and osteoporosis. Degenerative pathologies, injuries, and trauma can damage the bone tissues, requiring treatments that facilitate its repair, replacement, or regeneration. In this context, many materials have been developed to match this demand. Bioglasses and ceramics are promising inorganic materials to produce scaffolds for bone regeneration due to their attractive properties, such as biocompatibility, osteoinduction, and osteoconduction, besides their similarity with bone composition. Although their established advantages, these materials present limitations such as inadequate mechanical properties and fast degradation rate. Research work has been widely carried out to develop bioglasses, silicate, and phosphate calcium ceramics scaffolds with appropriated properties to enlarge their applications in bioengineering. Different fabrication techniques have also been evaluated. Incorporating other materials or particles, such as polymers, oxides and metal particles into the scaffolds has shown beneficial effects in mechanical strength and bone production stimulation. In this review, we provide an overview concerning the recent advances in developing calcium phosphates, calcium silicates, bioglasses, and composites scaffolds for bone regeneration in medical and dental applications. [ABSTRACT FROM AUTHOR]

Due to its high efficiency, low cost and a simple operation, the adsorption process is an important and widely used technique for industrial wastewater treatment. Recent studies on the removal of artificial dyes by adsorption include a large number of adsorbents, such as: activated carbon, silicates, carbon nanotube, graphene, fibers, titanates and doped titanates. The carbon insertion in the TiO 2 structure promotes a synergistic effect on the adsorbent composite, improving the adsorption and the charge-transfer efficiency rates. However, there are few studies regarding the adsorption capacity of TiO 2 /Carbon composites with the carbon concentration. This study evaluates the effect of carbon (resorcinol/formaldehyde) insertion on TiO 2 structure through the adsorption process. Adsorbents were prepared by varying the carbon weight percentages using the sol-gel method. The physicochemical properties of the catalysts prepared, such as crystallinity, particle size, surface morphology, specific surface area and pore volume were investigated. The kinetic study, adsorption isotherm, pH effect and thermodynamic study were examined in batch experiments using methylene blue as organic molecule. In addition, the effect of carbon phase on the adsorption capacity of TiO 2 -carbon composite was deeply investigated. SEM micrographs showed that TiO 2 phase grows along the carbon phase and FT-IR results showed the presence of Ti O C chemical bonding. The experiments indicate that the carbon phase acted as a nucleation agent for the growth of TiO 2 during the sol-gel step, with a TiO 2 structure suitable for blue methylene adsorption, resulting in a material with large surface area and slit-like or wedge-shaped pores. Further experiments will show the best carbon concentration for methylene blue adsorption using a TiO 2 based material. [ABSTRACT FROM AUTHOR]

• The Nb 2 O 5 doping caused a significant enhancement on the properties of the material. • ZnO-Nb 2 O 5 displayed improved photocatalytic efficiency under solar radiation. • EIS tests proved the enhancement of charge mobility in the ZnO-Nb 2 O 5. This project studied the development of niobium oxide-doped zinc oxide photocatalysts, aiming to increase the photocatalytic efficiency of zinc oxide (ZnO). Characterization results prove the existence of zinc oxide and niobium oxide (Nb 2 O 5) in the developed material. The addition of niobium oxide caused an increase in specific surface area and a decrease in the gap energy of the material. The results of 4-chlorophenol photodegradation show that the modified material displayed higher photocatalytic activity than pure ZnO. The superior photocatalytic activity is derived from the morphological and structural properties of the modified material, as well as from the heterojunctions formed between the semiconductors. The greater efficiency of charge transfer in the Nb 2 O 5 -doped material is demonstrated by the electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]