RESUMEN
Water treeing and water droplets are observed within adhesive layers and on the hybridized surface after bonding sound dentin using single-bottle etch-and-rinse adhesives, indicating permeability of the hybrid layer to water. The aim of this study was to assess the efficacy of dentin sealing by adhesives containing propolis by quantifying the area of water transudation from dentinal tubules after dentin hybridization. Brazilian red propolis was added to experimental adhesive and Single Bond (3M/ESPE) adhesive; experimental adhesive and Single Bond without propolis were used as controls. Under simulated pulp pressure, two layers of adhesive were applied to etched human dentin discs. Three minutes after light-curing, the hybridized dentin surface was replicated, and epoxy resin replicas were created to obtain scanning electron microscope images. Data were evaluated using ANOVA and Tukey's test. Single Bond containing propolis significantly decreased water permeation through the hybrid layer compared with the control group. Three minutes after polymerization, the experimental adhesive without propolis had formed a permeable hybrid layer. The addition of Brazilian red propolis significantly reduced surface water on hybridized dentin in a concentration-dependent manner. Two-step etch-and-rinse adhesives containing propolis were effective in reducing water permeation through the hybridized dentin surface.
RESUMEN
Schinus terebinthifolius Raddi has been extensively studied due to its antioxidant, anti-inflammatory and antibiotic properties. Recently, its seeds have been tested against some insect pests as an insecticide, repellent and antifungal agent. Microencapsulation by spray-drying is widely used in the food and drug industries, as well as in the microencapsulation of essential oils, since it protects the oils against several effects, such as oxidation and thermal degradation, thus optimising its use. The aim was to microencapsulate S. terebinthifolius essential oil by spray-drying maltodextrin and arabic gum as encapsulating agents and SiO2 as a colloidal adjuvant. The morphology of the microcapsules was analysed by scanning electron microscopy (SEM), which evidenced mainly regular spherical-shaped particles with sizes between 5 and 10 µm. The thermal stability was studied by thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), and the microcapsules were stable at temperatures up to 200°C. The microencapsulating agents and the spray-drying technique produced microcapsules capable of protecting the essential oil against external effects, such as thermal degradation.
RESUMEN
The aim of this study was to obtain a Brazilian red propolis (BRP) enriched composite resin and to perform the characterization of its antibacterial activity, mechanical, and physical-chemical properties. Brazilian red propolis ethyl acetate extract (EABRP) was characterized by LC-ESI-Orbitrap-FTMS, UPLC-DAD, antibacterial activity, total flavonoids content, and radical scavenging capacity. BRP was incorporated to a commercial composite resin (RC) to obtain BRP enriched composite at 0.1, 0.15 and 0.25% (RP10, RP15 and RP25, respectively). The antibacterial activity RPs was evaluated against Streptococcus mutans by contact direct test and expressed by antibacterial ratio. The RPs were characterized as its cytotoxicity against 3T3 fibroblasts, flexural strength (FS), Knoop microhardness (KHN), post-cure depth (CD), degree of conversion (DC%), water sorption (Wsp), water solubility (Wsl), average roughness (Ra), and thermal analysis. Were identified 50 chemical compounds from BRP extract by LC-ESI-Orbitrap-FTMS. EABRP was bacteriostatic and bactericide at 125 and 500 µg/ml, respectively. The RP25 exhibited antibacterial ratio of 90.76% after 1 h of direct contact with S. mutans (p < 0.0001) while RC no showed significative antibacterial activity (p = 0.1865), both compared with cell control group. RPs and RC no showed cytotoxicity. RPs exhibited CD from 2.74 to 4.48 mm, DC% from 80.70 to 83.96%, Wsp from 17.15 to 21.67 µg/mm3, Wsl from 3.66 to 4.20 µg/mm3, Ra from 14.48 to 20.76 nm. RPs showed thermal resistance between 448-455°C. The results support that propolis can be used on development of modified composite resins that show antibacterial activity and that have compatible mechanical and physical-chemical properties to the indicate for composite resins.
RESUMEN
OBJECTIVES: The aim of this study was to evaluate the degree of conversion and bond strength of a commercial dental adhesive modified by the incorporation of quercetin, resveratrol (RES), and Brazilian red propolis (BRP). METHODS: BRP markers were identified using ultra-performance liquid chromatography coupled with a diode array detector, and the antioxidant activity (AAO) of the three substances was analyzed. Single Bond 2 adhesive (3M ESPE) was modified by adding BRP, quercetin, and RES, separately, at 20 µg/mL, 250 µg/mL, and 500 µg/mL, respectively. The degree of conversion (DC) was measured using near-infrared spectroscopy 24 h after photopolymerization. Measurements of the resin-dentin microtensile bond strength (µTBS) were carried out after 1 day and 1 year. Student's t test and ANOVA with Tukey's test were used for data analysis (α = 0.05). RESULTS: The markers daidzein, liquiritigenin, pinobanksin, isoliquiritigenin, formononetin, pinocembrin, and biochanin A were found in the ethanolic extract of BRP. Quercetin, RES, and BRP showed high AAO. The DC of the tested adhesives remained adequate for this category of material, with a slight increase in the DC of adhesives with quercetin and BRP (P > 0.05). Comparisons between µTBS measurements made at 1 day and 1 year showed that, contrary to the control group, µTBS values for all modified adhesives were maintained after 1 year in distilled water (P > 0.05). CONCLUSIONS: These findings suggest that quercetin, RES, or BRP might be useful in adhesive dentistry to help improve hybrid layer resistance. CLINICAL SIGNIFICANCE: Dentin bonding agents with quercetin, RES, and BRP have potential to increase the longevity of composite restorations.
RESUMEN
The lepidopteran species Automeris liberia from the Saturniidae family is a polyphagous insect responsible for defoliating plants, such as the oil palm (Elaeis guineensis Jaquim). The antennae of insects play an important role in survival in various environments. Antennae are the main olfactory and sensory organs of insects and have different sensilla to detect chemical cues, movement, humidity and temperature. The olfactory structures present in the antennae are responsible for certain insect behavior, which is influenced by chemical communication. The morphology, distribution and location of the sensilla in the antennae of male and female A. liberia were investigated by scanning electron microscopy to understand the olfactory mechanisms relevant to insect-insect communication and insect-plant communication, among others. The results showed that the flagellum, scape and pedicel length and the number of antennomeres differed between the sexes and demonstrating the existence of sexual dimorphism in the antennae males (bipectinate) and females (filiform). According to the morphological data, seven types of sensilla were identified along the surface of the antennae, classified as trichodea, chaetica, basiconica, coeloconica, squamiformia, styloconica and Böhm's bristles. Among the sensilla chaetica, basiconica and Böhm's bristles, two subtypes based on length were identified in both sexes. The sensilla trichodea exhibited dimorphism since three subtypes were observed in males, while in females, only one subtype was observed, according to the length of the sensilla. Sensilla trichodea subtypes I and II were specific to males, while subtype III was observed in both sexes. These types of sensilla are involved in the recognition of pheromone molecules. Therefore, morphological study of the localization of the sensilla in the antennae will provide useful and relevant results for electrophysiological studies and behavioral tests. This information can help to understand the chemical communication of insects and helps in research directed strategies for pest control.