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•Hardystonite (Ca2ZnSi2O7) and the dicalcium silicate (β-Ca2SiO4, β-C2S) phases were synthesized and characterized.•Significant antibacterial effect of C2S-Hardystonite phase after 3 ...hours immersion in artificial saliva.•The findings suggest the material's potential application for treating teeth.
In recent years, there has been a growing interest in using bioceramics for dental restorations. These materials have shown promising results in terms of their ability to promote bioactivity and enhance adhesion between tooth tissues and restorative materials.the main aim of this study is to synthesize dicalcium silicate (β-Ca2SiO4, β-C2S) - Hardystonite (Ca2ZnSi2O7) phases as a new bioceramics restoration with good antibacterial ability and bioactivity. This type of material could be used as a denture base material, helping to preserve oral health by preventing the demineralization of the residual dentition through the release of appropriate ions that serve as substrates for hydroxyapatite formation. The hardystonite and the dicalcium silicate phases were synthesized by reaction in the solid state and addition of 5% proportion of Zinc nitrate (Zn (NO3)2). Moreover, the in vitro test was performed by immersing C2S-Hardystonite powder in artificial saliva for different times ranging from 1 h to 5 h to analyze the growth of hydroxyapatite (HA) on the surface of this powder. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transforms infrared (FTIR), Thermogravimetric analysis (TGA), differential thermal analysis (DTA) was utilized to analyze the samples for mineralogical and microstructural properties. The characterization of powder shows a mixture of C2S-Hardystonite phases with hydroxyapatite (Ca5(PO)4)3(OH)) and Tetracalcium phosphate (Ca4 (PO4)2O) phases precipitated on the surface of this powder within 1 h after soaking in artificial saliva. The micrographs obtained by SEM show fine particles of spherical agglomerates morphology attributed to hydroxyapatite phase. The antibacterial activity was tested by the Agar well diffusion method against two different strains. Staphylococcus aureus, Microbacterium resistant, Bacillus subtilis belong to the Gram-positive bacteria studied, and Escherchoa coli, Klebsiella pneumoniae and Pseudomonas chloritidismutans belong to the Gram-negative bacteria. Furthermore, the powder exhibited a shortened setting time and good injectability, along with an outstanding level of anti-washout performance. Finally, the results obtained suggest that dicalcium silicate-Hardystonite ceramics are promising candidates for dental restorations.
Topical agents are the mainstay in the treatment of xerostomia, a common complaint most frequently associated with salivary dysfunction. This study aimed to compared the efficacy and safety for ...xerostomia treatment of 2 artificial saliva preparations containing 0.1% pilocarpine, and, either sodium carboxymethylcellulose (SCMC), or, sodium polyacrylate (SPA).
Thirty-one xerostomia patients were randomly allocated into either a SCMC-treated group (15 patients), or, a SPA-treated group (16 patients). The formulations were taken 0.5 ml, 4 times daily for 6 weeks and double-blinded assessed before and after treatments using Xerostomia Inventory (XI) and Clinical Oral Dryness Score (CODs). Unstimulated and stimulated whole salivary flow rates were measured.
After treatment, the SCMC-treated group had significantly lower CODs and higher unstimulated and stimulated whole salivary flow rates (
<0.001,
=0.035, and
=0.013, respectively), while the SPA-treated group showed significantly lower CODs only (
=0.004). In contrast, SCMC-treated and SPA-treated groups at the 6th week after treatments showed non-significant differences in all assessments (
>0.05, all). Some adverse events (AEs) were reported, e.g., burning tongue, dizziness and watery eyes, but no severe AEs.
This randomized controlled pilot trial demonstrated superior efficacy of SCMC-formula over a SPA-formula after 6 weeks of xerostomia treatment. These formulations with topical pilocarpine proved safe in clinical use with minimal reported AE.
Xerostomia, artificial saliva, sodium carboxymethylcellulose, sodium polyacrylate, pilocarpine.
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•New hydroxyapatite electrodeposition procedure onto titanium is presented.•One precursor is added simultaneously with the application of a −1.5 V potential.•Higher crystallinity ...ceramic coatings compared to classical approach are obtained.•Ceramic coatings consisting in two layers crystallize onto metal surface.•Artificial saliva testing at 37 °C for 30 and 60 days was performed.
This paper presents hydroxyapatite (HA) coatings electrodeposited onto titanium by a new electrochemical approach: one precursor is present in the electrolysis cell, while the other precursor is dropwisely added, simultaneously with the application of an electrochemical potential. The addition order of the precursors was alternated, and the Ti substrate surface modifications were evidenced using various characterization methods. The coatings displayed higher crystallinity, with HA crystals organized into hemispheres, and a double ceramic layer configuration: one uniform base layer (submicrometric crystals), continuous in all cases and with higher density, and one upper layer (micrometric units), uniform only for longer deposition times and with lower density. Adhesion tests were performed to determine coating-substrate bonding strength. Artificial saliva solution tests conducted at 37 °C for 30 and 60 days were followed by XRD and SEM characterizations. The coatings could be useful for dentistry or orthopaedics applications, favouring the implant connection with the living tissue.
To bridge the gap between the current alarming literature on resin-based dental materials and the limited clinical observations, more precise knowledge on the actual quantity of released compounds ...should be acquired. The objective of this study was to quantify the long-term elution of various compounds from resin-based dental composites during one year.
Eight materials were investigated: G-aenial Anterior, G-aenial Posterior, Venus, Venus Pearl, Venus Diamond, Ceram X mono, Dyract and Filtek Supreme XTE. Cylindrical specimens (6 mm diameter, 2 mm thickness) were immersed in 1mL of three different extraction solutions (water, artificial saliva or ethanol) and stored in the dark at 37°C. Every week, the extraction solution was refreshed. The samples were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry.
BisEMA3, BisEMA6, BisEMA10, BisGMA, CQ, HEMA, TCD-DI-HEA, TEGDMA, and UDMA were quantified in the samples. Depending on the composite and the extraction solution, certain monomers (BisGMA, HEMA and UDMA) were able to continuously elute from the materials, up until 52 weeks after initial immersion. Monomer elution was clearly higher when ethanol was used as extraction solution. It could be demonstrated that the tested composites continued to release small quantities of monomers over longer periods when a continuous refreshing protocol is followed.
Even if monomer elution may not lead to a risk at short term, the potential long-term toxicity should be further investigated. Long-term elution and subsequent chronic exposure to monomers from resin-based dental materials should not be neglected when assessing the overall human health risks.
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Drug release within the oral cavity can be of paramount importance for formulations that are designed for specific purposes such as taste-masking, faster onset of therapeutic action, ...localization of treatment or avoidance of first-pass metabolism. Preclinical methods for assessment of dissolution in the oral cavity are necessary for design and development of these formulation but currently there is no consensus on what variables should be defined to achieve biorelevance in these tests. In this study, biorelevant simulated salivary fluids (SSFs) that can be uniformly applied for oral cavity dissolution testing were developed. Unstimulated saliva (US) SSF and stimulated saliva (SS) SSF were separately developed since the two states significantly differ. Physicochemical properties including pH, buffer capacity, surface tension and viscosity were assessed during development and optimised to mimic human saliva (HS). In order to account for the salivary proteins in HS, use of bovine submaxillary mucin (BSM) and porcine gastric mucin (PGM) in SSFs was evaluated. Following optimisation of the SSFs, biorelevance of the developed SSFs to HS was assessed by their comparative physicochemical properties as well as dissolution profiles of three diverse model compounds (sildenafil citrate, efavirenz, and caffeine) which showed comparable profiles between the SSFs and HS. This work addresses the lack of uniformed biorelevant dissolution media for oral cavity dissolution studies and provides a basis for standardised dissolution tests that provide consistency and harmonisation in future oral cavity dissolution studies. We envisage that this will have a positive impact on the development of new medicines that require functionality in the oral cavity.
Currently, sensitive and accurate approaches for diagnosis, rapid assessment, and cardiac biomarker monitoring in patients with heart failure are needed. In this context, the advantages of aptamers ...over traditional antibodies have been employed to fabricate a single-step impedimetric N-terminal pro b-type natriuretic peptide (NT-proBNP)-modified gold microelectrode array. The development of an electrochemical aptasensing platform was based on the coimmobilization of alkanethiol self-assembled monolayers and amine-terminated aptamer that specifically recognized cardiac NT-proBNP protein resulting in charge electron transfer. Electroimpedimetric signals of the sensor were observed to be linear to the NT-proBNP concentrations in the range of 5.0 × 10−3 to 1.0 pg mL−1 (R2 = 0.9624), while achieving a low detection limit of 5.0 × 10−3 pg mL−1. Clinically relevant detection levels for NT-proBNP were achieved in a simple, rapid, and label-free measurement using artificial saliva, which was highlighted to be specific, regenerative, and selective over potential interferers occurring during the processes of cardiac insufficiency, Therefore, the novel NT-proBNP aptasensor is a promising point-of-care tool exhibiting safe, non-invasive, affordable, and non-prescription home use accessible to overcome the limitations associated with conventional ELISA and previous aptasensing.
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•One-step impedimetric aptasensor was constructed for detecting NT-proBNP-related cardiac insufficiency.•NT-proBNP aptamer was easily tethered to gold microelectrode arrays by amine-gold interaction.•Excellent alternative aptasensor possessed ultrasensitively with a LOD of 5.0 × 10−3 pg mL−1 over immunosensors.•Aminated NT-proBNP-based one-step aptasensing was demonstrated in mimicked human saliva.
Isothiocyanates (ITCs) are products of the enzymatic breakdown of glucosinolates and may cause pungent flavor notes in vegetables. Limited data on odor threshold concentrations (OTCs) and odor ...quality descriptors of ITCs exist in literature. These parameters were determined in aqueous samples for 19 isothiocyanates found mainly in Brassica vegetables. Thresholds and odor quality descriptors were ascertained by panelists using flavor profile analysis (FPA). The odor threshold concentrations of ITCs range from 0.005 × 10−3 (octyl ITC) to 0.2 × 10−3 (ethyl ITC) g/L and ITCs were mainly characterized by sulfur, garlic, and Brassica vegetable-like notes. Correlation coefficients were between 0.946 (octyl ITC) and 0.996 (3-(methylthio)propyl ITC) and proved convincing results of OTCs using FPA.
Partition coefficients were determined in water, artificial saliva and human saliva to provide an insight into behavior of ITCs in two-phase liquid/air systems. Partition coefficients (K) for human saliva are significantly different from other matrices nevertheless the profile of ITCs K values in water and saliva buffer solution were similar. In human saliva the highest K values were observed for octyl, hexyl and cyclohexyl ITCs, and the lowest for cyclopropyl, benzyl, allyl ITCs. Obtained data provide essential and previously unknown sensory properties for future flavor studies.
•Isothiocyanates (ITCs) have low odor thresholds (μg/L) in aqueous samples.•The dominant qualities of the isothiocyanate odors are the smell of garlic and sulfur.•An increasing number of carbon atoms in ITC causes a decrease in the odor threshold.•Human saliva retains cyclopropyl ITC, benzyl ITC, and allyl ITC the most.•Octyl ITC, hexyl ITC, and cyclohexyl ITC are most released from human saliva.
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