Preparation of Cosmetic Emulsions Containing Hippophae Oil Isolated by Various Methods: Study of Their Antioxidant, Sun-Blocking and Physicochemical Properties.

An industry listed as one of the largest globally is the cosmetic industry. In recent years, this industry has shown growing interest in the application of natural ingredients providing advanced properties to cosmetic creams such as moisturizing, antioxidant, sun-protecting and antimicrobial effects. In this context, the present study concerns the production of cosmetic emulsions containing hippophae oil obtained via the methods of extraction, hydro-distillation and maceration using sunflower oil as the carrier oil. Firstly, an IR-ATR analysis was performed showing that the oils prepared were close to those commercially obtained. Then, the stability of the emulsions was tested over a time period of four months through measuring their pH and viscosity values with positive outcomes, and their antioxidant ability was also measured using the DPPH method. The latter one showed that hippophae oil greatly improves the antioxidant capacity. Moreover, based on the fact that sea buckthorn contains carotenoids, the SPF value of the emulsions was determined. The results showed that the addition of hippophae oil to the emulsions gave higher absorption in UV-Vis, thus higher SPF values. Py-GC/MS analysis was used to identify decomposition compounds in the produced oils. Among those, valuable compounds such as Ω-6, Ω-7 and Ω-9 fatty acids and many aldehydes were found by the decomposition of the oils.

Effect of radiant heat induced by a diode laser (445 nm) on setting process of glass-ionomer cements monitored by Fourier transform infrared spectroscopy.

OBJECTIVES: The aim of this study was to investigate the effect of thermal energy induced by a diode laser (445 nm) on the setting reactions of conventional glass ionomer cements (GICs) by using Fourier transform infrared spectroscopy (FTIR) and to compare it with that induced by a LED device. METHODS: Four GICs were investigated in this study (GlassIonomer FX Ultra, Ketac Universal Aplicap, Equia Fill, and Riva Self Cure). The experimental groups of the study were as follows (n = 5): Group 1 (control) - the specimens after mixing were left to set without any treatment; Group 2 - the specimens were irradiated for 60 s using a LED (Valo™) at 1400 mW/cm2 (fluence ∼ 1.4 J/cm2); Group 3 - the specimens were also irradiated for 60 s using a diode laser (SIROLaser Blue), which emits at 445 ± 5 nm with average output power of 0.7 W (fluence ∼ 1.4 J/cm2). FTIR analysis of the GIC specimens was followed to assess the changes in the COO-/CO ratios of the setting reaction and its progress in time. RESULTS: Both laser and LED treatments improved the setting reactions of the GICs compared to the control group (p < 0.05). However, this phenomenon was not observed in all materials implying that it may be material dependent. SIGNIFICANCE: Radiant heat treatments using diode laser or LED may be beneficial for the rate and progress of setting reaction of the conventional GICs. The composition and handling of the materials may be crucial for their final properties and the overall clinical behavior.

Overviews on the Progress of Flowable Dental Polymeric Composites: Their Composition, Polymerization Process, Flowability and Radiopacity Aspects.

A review article has been conducted including the main research results and comments referring to flowable dental polymeric materials. To begin with, the synthesis and composition of this category of composites is discussed, revealing the major components of the commercial products in terms of chemistry and proportion. Later, the polymerization characteristics are unfolded regarding the reaction time and rate, volumetric shrinkage and depth of cure for both photocurable and self-curable composites. To continue, some perspectives of the pre-treatment or accompanying processes that a clinician may follow to enhance the materials' performance are described. Fluidity is certainly associated with the progress of polymerization and the in-depth conversion of monomers to a polymeric network. Last, the aspects of radiopacity and translucency are commented on, showing that all flowable polymeric composites satisfy the radiography rule, while the masking ability depends on the fillers' properties and specimen thickness. The reviewing article is addressed to all field scientists and practitioners dealing with flowable dental composites studies or applications.

Development of Bio-Composites with Enhanced Antioxidant Activity Based on Poly(lactic acid) with Thymol, Carvacrol, Limonene, or Cinnamaldehyde for Active Food Packaging.

The new trend in food packaging films is to use biodegradable or bio-based polymers, such as poly(lactic acid), PLA with additives such as thymol, carvacrol, limonene or cinnamaldehyde coming from natural resources (i.e., thyme, oregano, citrus fruits and cinnamon) in order to extent foodstuff shelf-life and improve consumers' safety. Single, triple and quadruple blends of these active compounds in PLA were prepared and studied using the solvent-casting technique. The successful incorporation of the active ingredients into the polymer matrix was verified by FTIR spectroscopy. XRD and DSC data revealed that the crystallinity of PLA was not significantly affected. However, the Tg of the polymer decreased, verifying the plasticization effect of all additives. Multicomponent mixtures resulted in more intense plasticization. Cinnamaldehyde was found to play a catalytic role in the thermal degradation of PLA shifting curves to slightly lower temperatures. Release of thymol or carvacrol from the composites takes place at low rates at temperatures below 100 °C. A combined diffusion-model was found to simulate the experimental release profiles very well. Higher antioxidant activity was noticed when carvacrol was added, followed by thymol and then cinnamaldehyde and limonene. From the triple-component composites, higher antioxidant activity measured in the materials with thymol, carvacrol and cinnamaldehyde.

Sorption characteristics of oral/food simulating liquids by the dental light-cured nanohybrid composite Kalore GC.

OBJECTIVE: This work presents the results obtained from the study of sorption/desorption process of some food/oral simulating liquids (FSLs) by the new marketed dental light-cured nanohybrid composite Kalore GC. METHODS: The sorption/desorption process followed is recommended by ISO 4049:2009. The samples were immersed in various liquids proposed by ADA as FSLs, such as H2O, artificial saliva, EtOH, EtOH/H2O solution (75vol%) or C7H16, while the mass change for totally 30 days was recorded on defined time intervals. Afterwards the samples were put in dry desiccators at 37°C for the study of desorption process. RESULTS: The weight percentage of sorption of the above mentioned FSLs by Kalore GC was determined; also the wt% of the desorbed liquid, the diffusion coefficient of sorption and desorption, the wt% solubility and the % volume increase due to the liquid sorption. SIGNIFICANCE: The sorption characteristics of a dental composite depend both on composite structure and liquid. Ethanol/water and ethanol showed the highest effect on the determined characteristics. Then, the water and SAGF(®) saliva follows and finally the heptane solvent.

Dynamic mechanical thermal properties of the dental light-cured nanohybrid composite Kalore, GC: effect of various food/oral simulating liquids.

OBJECTIVE: The aim of this work is the study of the dynamic mechanical thermal properties (viscoelastic properties) of a current dental commercial light-cured nanohybrid resin composite, Kalore, GC (GC Corporation, Tokyo, Japan) along with the study of the effect of some food/oral simulating liquids (FSLs) on these properties. METHODS: Dynamic mechanical thermal analysis (DMTA) tests were performed on a Diamond Dynamic Mechanical Thermal Analyzer in bending mode. A frequency of 1Hz and a temperature range of 25-185°C were applied, while the heating rate of 2°C/min was selected to cover mouth temperature and the material's likely Tg. The properties were determined after storage in air, distilled water, heptane, ethanol/water solution (75% v/v) or absolute ethanol at 37°C for up to 1h, 1, 7 or 30 days. RESULTS: Storage modulus, loss modulus and tangent delta (tanδ) were plotted against temperature. The glass transition temperatures are taken from the peak of the tangent tanδ versus temperature curves. Moreover, some factors indicating the heterogeneity of the polymer matrix, such as the width (ΔT) at the half of tanδ peak and the "ζ" parameter were determined. All samples analyzed after storage for 1h or 1 day in the aging media showed two Tg values. All samples analyzed after storage for 7 or 30 days in the ageing media showed a unique Tg value. SIGNIFICANCE: Storage of Kalore GC in dry air, water or heptane at 37°C for 7 days caused post-curing reactions. Storage in air or water for 30 days did not seem to cause further effects. Storage in heptane for 30 days may cause plasticization and probably some degradation of the filler-silane bond and polymer matrix. Storage in ethanol/water solution (75% v/v) or ethanol for 7 days seems to cause post-curing reactions and degradation reactions of the matrix-filler bonds. Storage in ethanol for 30 days caused a strong change of the sample morphology and the DMTA results were not reliable.

Effect of food/oral-simulating liquids on dynamic mechanical thermal properties of dental nanohybrid light-cured resin composites.

OBJECTIVE: The purpose of this work was the study of the effect of food/oral simulating liquids on the dynamic mechanical thermal properties (viscoelastic properties) of current commercial dental light-cured resin composites characterized as nanohybrids. These nanohybrids were Grandio, Protofill-nano and Tetric EvoCeram. METHODS: The properties were determined under dry conditions (1h at 37°C after light-curing) and also after storage in dry air, distilled water, artificial saliva SAGF(®) or ethanol/water solution (75 vol%) at 37°C for up 1, 7, 30 or 90 days. Dynamic mechanical thermal analysis tests were performed on a Diamond Dynamic Mechanical Analyzer in bending mode. A frequency of 1Hz and a temperature range of 25-185°C were applied, while the heating rate of 2°C/min was selected to cover mouth temperature and the materials' likely Tg. RESULTS: Storage modulus, loss modulus and tangent delta were plotted against temperature over this period. The Tg of composites was obtained as the temperature indicated by tanδ peak. Moreover, the maximum height of tanδ peak, the width at the half of tanδ maximum and a parameter known as "ζ" parameter were determined. All composites analyzed 1h after light-curing and 1 day in air or in food/oral simulating liquids showed two Tg. All composites stored for 7, 30 or 90 days in any medium showed unique Tg value. Also among the various properties studied the most sensible in the structural changes of composites seems to be the Tg. SIGNIFICANCE: Storage of composites in dry air at 37°C which is very close to their Tg (40°C) for 1 or 7 days caused post curing reactions, while storage for 30 or 90 days has no further effect on composites. Storage in water or artificial saliva 37°C for 1 or 7 days caused post curing reactions, while storage for 30 or 90 days seems to cause plasticization effect affecting some parameters analogously. Storage in ethanol/water solution (75vol%) 37°C for 1 or 7 days caused also post curing reactions, while storage for 30 or 90 days caused plasticization and/or probable oxidation/hydrolysis of polymeric network.

Dynamic mechanical properties of dental nanofilled light-cured resin composites: Effect of food-simulating liquids.

This work is aimed at the study by dynamic mechanical analysis (DMA) of viscoelastic properties that is, the elastic modulus (E'), the loss modulus (E″), the loss tangent (tanδ) and the glass transition temperature (T(g)), of two current commercial light-cured resin composites, Filtek Supreme Body and Filtek Supreme Translucent, characterized as nanofilled. These composites show differences in the filler content and type. For DMA analysis the bar-shaped specimens were divided into groups of three samples each. The first group consisted of dry samples measured 1 h after light-curing (at room temperature) during which they were placed in a desiccator at 37 °C. The other groups consisted of samples which had been stored in air, distilled water, artificial saliva SAGF or ethanol/water solution (75 v/v), at 37±1 °C for 1, 7, 30 or 90 days. DMA tests were performed on a Diamond Dynamic Mechanical Analyzer (Perkin-Elmer) in bending mode. A frequency of 1 Hz was applied and a temperature range of 25-185 °C, while a heating rate of 2 °C/min were selected to cover mouth temperature and the materials' likely T(g). The studied dry composites showed comparable values for their properties in spite of their differences in the filler content and type. Storage of composites in air 37 °C for 1 day caused a significant post curing which was not continued during storage up to 90 days. Water and artificial saliva showed the same effect on composites. They caused both post curing and plasticization. Ethanol/water solution 75% v/v had a more strong effect than water and artificial saliva due to its organophilic nature. It caused post curing, plasticization and most probably degradation of the bond filler-silane coupling agent.