[Application of ultrasonic irrigation combined with chlorhexidine in root canal treatment of pulpitis].

PURPOSE: To explore the clinical effect of ultrasonic irrigation combined with chlorhexidine in root canal treatment of pulpitis. METHODS: A total of 120 patients with pulpitis treated with root canal therapy were randomly divided into a study group (n=60, 72 affected teeth) and a control group (n=60, 70 affected teeth). During root canal preparation, the study group was treated with chlorhexidine combined with ultrasonic irrigation, while the control group was treated with chlorhexidine conventional irrigation. The bacterial count and endotoxin content in the root canal before and after root canal preparation were compared between the two groups, as well as the endodontic inter-appointment pain (EIAP), lateral branch root canal filling rate, and degree of tooth pain after root canal treatment. The success rate of treatment was statistically analyzed after one-year follow-up. Statistical analysis was performed with SPSS 19.0 software package. RESULTS: After root canal preparation, the number of colonies in experimental group and control group was significantly decreased compared with that before root canal preparation(P＜0.05), and the number of colonies in experimental group was significantly lower than that in control group(P＜0.05). After root canal preparation, endotoxin levels in experimental group and control group were significantly lower than those before root canal preparation(P＜0.05), and the level in experimental group was significantly lower than that in control group(P＜0.05). The lateral branch root canal filling rate in the study group and the control group was 29.17% and 11.43%, respectively, with significant difference between the groups(P＜0.05). The incidence of EIAP was 4.17% and 14.29%, respectively, with significant difference between the two groups(P＜0.05). At 48 hours after surgery, the visual analogue score (VAS) of the study group and the control group was (2.74±0.61) and (3.29±0.68), respectively, which were significantly lower than at before surgery(P＜0.05). There was a significant difference in VAS score between the two groups 48 hours after surgery(P＜0.05). One week after surgery, the VAS score in the study group and the control group was (1.52±0.34) and (1.81±0.42), respectively, significantly lower than that before and 48 hours after surgery(P＜0.05). There was a significant difference in VAS score between the two groups at one week after surgery (P＜0.05). The successful rate of treatment in the control group was 84.62%, and 95.71% in the study group, with a significant difference between the two groups(P＜0.05). CONCLUSIONS: The application of ultrasonic irrigation combined with chlorhexidine in the treatment of pulpitis root canals can help reduce the level of bacteria and endotoxin after root canal preparation, alleviate the degree of postoperative tooth pain, and improve the filling rate of lateral branch root canals, with superior curative effects.

Effect of ultrasonic activation on setting time, pH and calcium ion release, solubility, and chemical structure of calcium silicate sealers.

This study evaluated the setting time, pH, calcium ion release, solubility, and chemical structure of four calcium silicate sealers after ultrasonic activation (UA). Five sealers were evaluated: Sealer Plus (SP - control); Sealer Plus BC (SPBC), Bio C Sealers (BCS), Endosequence BC Sealer (EBC), and BioRoot RCS (BR). Ten groups were created based on the use or not of ultrasonic activation: SP; SP/UA; SPBC; SPBC/UA; BCS; BCS/UA; EBC; EBC/UA; BR; and BR/UA. Setting time was performed based on ISO 6876:2012 and ASTM C266-07 specifications. Solubility at 24hs, based on ISO 6876:2012. pH and calcium release were evaluated at 1, 24, 72, and 168hs. Raman spectroscopy was used to evaluate structural changes. Quantitative data were analyzed using One-Way ANOVA and Tukey post-hoc test (α=5%). Raman spectroscopy results were qualitatively analyzed. Setting times and solubility of all sealers were not affected by UA (p>0.05). The highest solubility was found for BCS, BCS/UA; and BR, BR/UA (p<0.05). After 24hs, calcium silicate sealers had higher pH than SP and SP/UA (p<0.05). BR and BR/UA had the highest pH at all time points. SP and SP/UA had stable pH at all time points. SP and SP/UA had the lowest calcium release values at all time points (p<0.05). EBC and EBC/UA calcium release significantly differ at 24,72 and 168hs (p<0.05). No chemical changes were observed during Raman spectroscopy. In conclusion, ultrasonic activation affected calcium ion release only for EndoSequence BC Sealer. Ultrasonic activation did not influence the initial and final setting time, solubility, pH, and chemical structure of any investigated sealers.

Filling ability of ready-to-use or powder-liquid calcium silicate-based sealers after ultrasonic agitation.

This study evaluated the effect of ultrasonic agitation on the filling capacity of ready-to-use calcium silicate-based sealer Bio-C Sealer (BCS, Angelus, Paraná, Brazil) or powder-liquid BioRoot RCS (BR, Septodont, Saint-Maur-des-Fossés, France) using curved artificial canals by micro-computed tomography (micro-CT). Additionally, flow (mm) and flow area (mm2) were evaluated for both materials. Acrylic resin main canal (60° curvature and 5 mm radius, with 3 lateral canals in the cervical, middle, and apical thirds) were prepared up to size 40/.05 (Prodesign Logic, Brazil). The agitation method was used with ultrasonic tip (US, Irrisonic, Helse, Brazil): BCS, BCS/US, BR, and BR/US. All specimens were filled using the single-cone technique. The samples were scanned by micro-CT (8,74 µm) after obturation. The percentage of filling material and voids were calculated. Flow was evaluated based on ISO 6876/2012 standards (mm) and area (mm2). The data were statistically analyzed using ANOVA and Tukey tests (α = 0.05). BR/US showed lower percentage of filling material in the lateral canals than and, BCS/US (p<0.05). BR/US resulted in a higher percentage of voids than BR in the lateral apical third (p<0.05). BCS showed higher flow than BR (p<0.05). BCS and BR presented proper filling capacity in the simulated curved canals regardless of the use of ultrasonic agitation. However, BR/US showed more voids in the apical third. BCS demonstrates higher filling ability.

Effect of the Combined Ultrasound with Other Technologies on Food Allergenicity: Ultrasound before, under, and after Other Technologies.

Food allergies are a main public health disease in the world. Ultrasound is an environmentally friendly technology that typically leads to protein unfolding and loss of protein structure, which means it has the potential to be combined with other technologies to achieve a great reduction of allergenicity in foods. This review concludes the effects of the combined ultrasound with other technologies on food allergenicity from three combinations: ultrasound before other technologies, ultrasound under other technologies, and ultrasound after other technologies. Each combination affects food allergenicity through different mechanisms: (1) as for ultrasound before other technologies, ultrasound pretreatment can unfold and lose the protein structure to improve the accessibility of other technologies to epitopes; (2) as for ultrasound under other technologies, ultrasound can continuously affect the accessibility of other technologies to epitopes; (3) as for ultrasound after other technologies, ultrasound further induces structural changes to mask and disrupt the epitopes. The reduction of allergenicity is related to the ultrasound/other technologies conditions and food types/cultivars, etc. The comparison of ultrasound before, under, and after other technologies to decrease food allergenicity should be further investigated in the future. The combination of ultrasound with other technologies is promising to produce hypoallergenic foods.

Developing a method to measure bioavailable phosphorus in river water via simultaneous multisample ultrasonic extraction.

To reduce aquatic eutrophication, measurements of bioavailable phosphorus (BAP) rather than total phosphorus (TP) are deemed critical. However, current methods require much time to separate sediments from river water, which limits the routine measurement of BAP in rivers. Therefore, in this study, a simultaneous multisample ultrasonic extraction method is proposed to directly measure total BAP (TBAP) in river water without the separation of sediment and water. Spike-and-recovery assessments showed that at least three extractions are required to maintain efficiency. A process including 2-min extraction time and three extractions was suggested. The concentrations of TBAP extracted by this process showed no significant differences with the spike calculations. Furthermore, river water TBAP was quantified using the conventional and proposed method to examine the practicality of using the proposed method for simultaneous multisample ultrasonic extraction and to evaluate its adaptability to actual river water analysis. The extracted concentrations matched those obtained using the conventional method, in which total BAP is calculated as the sum of dissolved BAP and particulate BAP; no significant difference was observed between the concentrations. Ultrasonic extraction was considerably less time-consuming than the conventional method because more samples could be analyzed during a single run. Therefore, the simultaneous multisample ultrasonic extraction method proposed in this study can be used to directly quantify total BAP in river water.

Microbial and physicochemical changes in green bell peppers treated with ultrasonic-assisted washing in combination with Thymus vulgaris essential oil nanocapsules.

In this study, the effect of Thymus vulgaris essential oil (TVO) nanoemulsion (NE, 500 mg/L) in combination with ultrasound (ultrasound-NE) on the microbial and physiological quality of green bell pepper was investigated. The TVO-NE droplet size and zeta potential were 84.26 nm and - 0.77 mV, respectively. The minimum inhibitory concentrations of the TVO and TVO-NE against E. coli and S. aureus were about 0.07 and 7 g/L, respectively. The NE-ultrasound treatment exhibited the lowest peroxidase activity and respiration rate with no detrimental effect on texture, total phenolic content, antioxidant activity, pH, and TSS. Although the NE-ultrasound treatment showed the highest weight loss and electrolytic leakage, it exhibited the best visual color and appearance. The NE-ultrasound treatment descended the total viable/mold and yeast counts significantly compared to control. Results showed that treating the bell peppers with NE-ultrasound can result in bell peppers with good postharvest quality and extended shelf life.

Quality and stability of frying oils and fried foods in ultrasound and microwave-assisted frying processes and hybrid technologies.

Frying is a popular cooking method that produces delicious and crispy foods but can also lead to oil degradation and the formation of health-detrimental compounds in the dishes. Chemical reactions such as oxidation, hydrolysis, and polymerization contribute to these changes. In this context, emerging technologies like ultrasound-assisted frying (USF) and microwave (MW)-assisted frying show promise in enhancing the quality and stability of frying oils and fried foods. This review examines the impact of these innovative technologies, delving into the principles of these processes, their influence on the chemical composition of oils, and their implications for the overall quality of fried food products with a focus on reducing oil degradation and enhancing the nutritional and sensory properties of the fried food. Additionally, the article initially addresses the various reactions occurring in oils during the frying process and their influencing factors. The advantages and challenges of USF and MW-assisted frying are also highlighted in comparison to traditional frying methods, demonstrating how these innovative techniques have the potential to improve the quality and stability of oils and fried foods.

Ultrasonic activation of adhesive systems increases bond strength and intratubular penetration of resin cement in root dentin subjected to radiation therapy.

OBJECTIVE: This study aimed to evaluate the effect of ultrasonic activation of etch-and-rinse and self-etch adhesive systems on the bond strength of resin cement to irradiated root dentin. MATERIALS AND METHODS: Eighty human maxillary anterior teeth were distributed into 8 groups (n = 10), according to the type of adhesive system used (etch-and-rinse and self-etch), the ultrasonic activation of the adhesive systems, and the dentin condition (irradiated or non-irradiated - 70 Gy). Endodontic treatment was performed followed by fiberglass post-space preparation. After fiberglass posts' luting, the roots were transversely sectioned on dentin discs and submitted to the push-out bond strength test (0.5 mm/min). The fractured specimens were analyzed under a stereomicroscope and Scanning Electron Microscope (SEM) for failure mode classification. One of the dentin discs was analyzed under SEM to evaluate the characteristics of the adhesive interface. RESULTS: Irradiated specimens had lower bond strength than non-irradiated specimens (P < 0.0001). Ultrasonic activation of both adhesive systems increased the bond strength of the resin cement to irradiated dentin (P < 0.0001). Radiotherapy significantly affected the failure mode in the middle (P = 0.024) and apical thirds (P = 0.032) (adhesive failure). CONCLUSION: Non-irradiated specimens had a more homogeneous adhesive interface. When ultrasonically activated, both adhesive systems showed a greater number of resinous tags, regardless of the dentin condition. CLINICAL RELEVANCE: Ultrasonic activation of adhesive systems is a feasible strategy to enhance fiberglass posts retention in oncological patients.

EchoGest: Soft Ultrasonic Waveguides Based Sensing Skin for Subject-Independent Hand Gesture Recognition.

Gesture recognition is crucial for enhancing human-computer interaction and is particularly pivotal in rehabilitation contexts, aiding individuals recovering from physical impairments and significantly improving their mobility and interactive capabilities. However, current wearable hand gesture recognition approaches are often limited in detection performance, wearability, and generalization. We thus introduce EchoGest, a novel hand gesture recognition system based on soft, stretchable, transparent artificial skin with integrated ultrasonic waveguides. Our presented system is the first to use soft ultrasonic waveguides for hand gesture recognition. EcoflexTM 00-31 and EcoflexTM 00-45 Near ClearTM silicone elastomers were employed to fabricate the artificial skin and ultrasonic waveguides, while 0.1 mm diameter silver-plated copper wires connected the transducers in the waveguides to the electrical system. The wires are enclosed within an additional elastomer layer, achieving a sensing skin with a total thickness of around 500 µ m. Ten participants wore the EchoGest system and performed static hand gestures from two gesture sets: 8 daily life gestures and 10 American Sign Language (ASL) digits 0-9. Leave-One-Subject-Out Cross-Validation analysis demonstrated accuracies of 91.13% for daily life gestures and 88.5% for ASL gestures. The EchoGest system has significant potential in rehabilitation, particularly for tracking and evaluating hand mobility, which could substantially reduce the workload of therapists in both clinical and home-based settings. Integrating this technology could revolutionize hand gesture recognition applications, from real-time sign language translation to innovative rehabilitation techniques.

Ultrasonic treatment of endocrine disrupting compounds, pharmaceuticals, and personal care products in water: An updated review.

Pharmaceuticals, personal care products (PPCPs), and endocrine-disrupting compounds (EDCs) have seen a recent sustained increase in usage, leading to increasing discharge and accumulation in wastewater. Conventional water treatment and disinfection processes are somewhat limited in effectively addressing this micropollutant issue. Ultrasonication (US), which serves as an advanced oxidation process, is based on the principle of ultrasound irradiation, exposing water to high-frequency waves, inducing thermal decomposition of H2O while using the produced radicals to oxidize and break down dissolved contaminants. This review evaluates research over the past five years on US-based technologies for the effective degradation of EDCs and PPCPs in water and assesses various factors that can influence the removal rate: solution pH, temperature of water, presence of background common ions, natural organic matter, species that serve as promoters and scavengers, and variations in US conditions (e.g., frequency, power density, and reaction type). This review also discusses various types of carbon/non-carbon catalysts, O3 and ultraviolet processes that can further enhance the degradation efficiency of EDCs and PPCPs in combination with US processes. Furthermore, numerous types of EDCs and PPCPs and recent research trends for these organic contaminants are considered.

Correlation between disinfection efficacy and cumulative amount of free chlorine reaching various positions during ultrasonic fogging with hypochlorite solution.

When a hypochlorite solution is ultrasonically fogged in a room, free chlorine, i.e., HOCl and OCl-, reaches various positions in two forms: fine fog droplets and gaseous hypochlorous acid（HOCl(g)）. In this study, the cumulative amount of free chlorine reaching various positions on the floor away from the fogger was measured in a 90-m3 room, using a sulfamate-carrying glass-fiber filter indicator. The fine droplets were blown out from the fogger into the spaces at different discharge port angles of 30 - 90°. Free chlorine was successfully trapped by sulfamate, forming monochlorosulfamate, which was stably retained on the indicator. The cumulative amount of free chlorine（ ng/indicator） increased with fogging time at each position and depended on the blow angle and distance from the fogger. Minor differences in the HOCl(g) concentration near the floor at all positions were observed. The disinfection efficacy of the fogging treatment against Staphylococcus aureus on wet surfaces was relatively higher at positions near the fogger and lower at positions far from the fogger. At each discharge port angle, a strong correlation between the logarithmic reduction in relative viable cells and the cumulative amount of free chlorine reaching S. aureus plates was observed. The slopes of the regression lines of correlation diagrams as a function of the cumulative amount of free chlorine were between -0.0362 and -0.0413 ng-1. This study demonstrated that the cumulative amount of free chlorine measured using the filter indicator could reflect the sum of the free chlorine of both fine droplets and HOCl(g), and that the disinfection efficiency depended on the cumulative amount of free chlorine reaching different areas.

The effect of ultrasound on the extraction and foaming properties of proteins from potato trimmings.

High-intensity ultrasonication is an emerging technology for plant protein isolation and modification. In this study, the potential of temperature-controlled ultrasonication to enhance the recovery of functional proteins from potato trimmings was assessed. Different ultrasound energy levels [2000-40,000 J/g fresh weight (FW)] were applied during protein extraction at pH 9.0. True protein yields after ultrasonication significantly increased (up to 91%) compared to conventional extraction (33%). Microstructural analysis of the extraction residues showed more disrupted cells as ultrasonication time increased. Ultrasound treatments (10,000 and 20,000 J/g FW) increased the protein yield without affecting the foaming and air-water interfacial properties of protein isolates obtained after isoelectric precipitation (pH 4.0). However, proteins obtained after extended ultrasonication (40,000 J/g FW) had significantly slower early-stage adsorption kinetics. This was attributed to ultrasound-induced aggregation of the protease inhibitor fraction. In conclusion, ultrasonication shows potential to help overcome some challenges associated with plant protein extraction.

Coupling of cold atmospheric plasma treatment with ultrasound-assisted extraction for enhanced recovery of bioactive compounds from cornelian cherry pomace.

Cornelian cherry pomace is produced during the production of juice from this traditional superfood. Due to its high nutritive value, the by-product can be utilized as a source of bioactive compounds. The present study aimed to develop a sustainable methodology for the recovery of bioactive compounds based on the combination of atmospheric cold plasma (CAP) with ultrasound assisted extraction. The pomace was treated with cold plasma under different conditions. Cyclodextrin was used as green extraction enhancer due to its capacity to develop inclusion complexes with bioactive compounds. CAP pretreatment before extraction appeared to enhance the recovery of the target compounds. GC-MS analysis and in vitro digestion analysis conducted in order to evaluate the composition and the protentional bioavailability of the bioactive compounds. CHEMICALS COMPOUNDS: ß-cyclodextrin (PubChem CID: 444041), DPPH free radical (PubChem CID: 2735032), Trolox (PubChem CID: 40634), sodium carbonate (PubChem CID: 10340), gallic acid (PubChem CID: 370) potassium chloride (PubChem CID: 4873), sodium acetate (PubChem CID: 517045), loganic acid (PubChem CID: 89640), pyridine (PubChem CID: 1049, BSTFA(PubChem CID: 94358), potassium chloride (PubChem CID: 4873), ammonium carbonate (PubChem CID: 517111), calcium chloride dehydrate (PubChem CID: 24844), potassium dihydrogen phosphate (PubChem CID: 516951), magnesium chloride hexahydrate (PubChem CID: 24644), sodium hydrogen carbonate (PubChem CID: 516892), sodium chloride (PubChem CID: 5234).

Alternative green solvents associated with ultrasound-assisted extraction: A green chemistry approach for the extraction of carotenoids and chlorophylls from microalgae.

This study proposes a method for the ultrasonic extraction of carotenoids and chlorophyll from Scenedesmus obliquus and Arthrospira platensis microalgae with green solvents. Ethanol and ethanolic solutions of ionic liquids were tested with a variety of extraction parameters, including number of extractions, time of extraction, and solid-liquid ratio R(S/L), to determine the optimal conditions. After selecting the most effective green solvent (ethanol), the process conditions were established: R(S/L) of 1:10, three extraction cycles at 3 min each), giving an extraction yield of 2602.36 and 764.21 µgcarotenoids.gdried biomass-1; and 22.01 and 5.81 mgchlorophyll.gdried biomass-1 in S. obliquus and A. platensis, respectively. The carotenoid and chlorophyll extracts obtained using ethanol were shown to be potent scavengers of peroxyl radical, being 5.94 to 26.08 times more potent α-tocopherol. These findings pave the way for a green strategy for valorizing microalgal biocompounds through efficient and environmentally friendly technological processes.

Sustainable proteins from wine industrial by-product: Ultrasound-assisted extraction, fractionation, and characterization.

Plant proteins are increasingly being used in the food industry due to their sustainability. They can be isolated from food industry waste and converted into value-added ingredients, promoting a more circular economy. In this study, ultrasound-assisted alkaline extraction (UAAE) was optimized to maximize the extraction yield and purity of protein ingredients from grapeseeds. Grapeseed protein was extracted using UAAE under different pH (9-11), temperature (20-50 °C), sonication time (15-45 min), and solid/solvent ratio (10-20 mL/g) conditions. The structural and functional attributes of grapeseed protein and its major fractions (albumins and glutelins) were investigated and compared. The albumin fractions had higher solubilities, emulsifying properties, and in vitro digestibilities but lower fluid binding capacities and thermal stability than the UAAE and glutelin fraction. These findings have the potential to boost our understanding of the structural and functional characteristics of grapeseed proteins, thereby increasing their potential applications in the food and other industries.

Municipal sewage sludge dewatering performance enhancement by ultrasonic cavitation and advanced oxidation: A case study.

The number of published literature on the effect of ultrasonic cavitation and advanced oxidation pretreatment on the dewatering performance of anaerobically digested sludge is very limited. This study aims at determining the optimum operating conditions of large-scale filtering centrifuges in wastewater treatment plants. The optimum dose of hydrogen peroxide, ultrasonic power, ultrasonic duration, ultrasonic pulse and particle size distribution for improved dewatering performance were determined in this study. In addition, shear stress-shear rate and viscosity-shear rate rheograms were developed to show the rheological flow properties for varying ultrasonic power and treatment duration. Optimum sonication power, time, pulse and amplitude were determined to be 14 W, 1 min, 55/5 and 20%, respectively. At a pH of 6.8, the optimum concentration of hydrogen peroxide was found to be 43.5 g/L. The optimum hydrogen peroxide dose in the combined conditioning experiments was determined to be 500 mg/L at a pH of 3. Under these optimum conditions, capillary suction time was reduced significantly by 71.1%. This study helps to reduce polymer consumption and provides the optimum pretreatment and dewatering operating conditions, and better monitoring and control in the dewatering unit has significant impact in the overall economy of wastewater treatment plants.

Ultrasound-assisted extraction of bioactive compounds from goji berries: Optimization, bioactivity, and intestinal permeability assessment.

Lycium barbarum L. berries have a remarkable chemical composition and extensive biological activities, being a valuable component of health and nutraceutical practices. Nevertheless, a deep insight on the intestinal permeation of the pro-healthy bioactive compounds is urgently needed to predict the real effects on human body. This study attempted, for the first time, to optimize the Ultrasound-Assisted Extraction (UAE) of goji berries using a Response Surface Methodology approach and establish the intestinal permeation of the principal pro-healthy compounds. The optimal extraction conditions were a solid:liquid ratio of 8.75 % for 56.21 min, using an intensity of 59.05 W/m2. The optimal extract displayed a remarkable antioxidant capacity, with LC/DAD-ESI-MS analysis unveiled a diverse phytochemical profile, encompassing different compounds (e.g. glu-lycibarbarspermidine F, 2-glu-kukoamine, rutin, 3,5-dicaffeoylquinic acid). The intestinal co-culture model demonstrated that glu-lycibarbarspermidine F (isomer 2) (73.70 %), 3,5-dicaffeoylquinic acid (52.66 %), and isorhamnetin-3-O-rutinoside (49.31 %) traversed the intestinal cell layer, exerting beneficial health-promoting effects.

Regulation of fat crystals in water-in-oil emulsions by high-intensity ultrasound: Crystal size and tracing of droplet distribution.

In this paper, two emulsion systems with high and low solid fat contents were prepared from 20 % water phase and 80 % oil phase by adjusting the palm oil/palm stearin/soybean oil ratio. Different ultrasonic power and time were used for the pretreatment of emulsion with different solid fat content, and the application characteristics of ultrasonic in W/O emulsions were explored and evaluated. Directly using high-intensity ultrasound to prepare fatty emulsions would weaken the hardness and storage modulus G' of the samples. Although ultrasound reduced the size of fat crystals in emulsions, the interaction between water droplets and fat crystals needs to be considered. After ultrasonic treatment, water droplets were difficult to immobilize on the crystal surface and thus acted as an active filler to stabilize the emulsion together with the fat crystal network. In high solid fat emulsion systems, an increase in ultrasound power (from 100 W to 200 W) could more affect the crystallization behavior of fats than an increase in ultrasound duration (from 30 s to 60 s), and the distribution of crystals and droplets was more uniform. In the low solid fat emulsion system, the texture of the sample after ultrasonic treatment was softer, and the surface was more delicate and smoother. However, the higher ultrasonic intensity (200 W) was not conducive to the preparation of the spread. Although the ultrasound with excessive intensity promoted the formation of small crystals, it would also lead to the aggregation of small crystals. These small crystals cannot form a uniform crystal network, which increases the fluidity of emulsions.

Ultrasound combined with microwave hydrodiffusion and gravity for enhancement of caffeine extraction from guarana powder.

The extraction of valuable compounds from dried fruits and vegetables by microwave hydrodiffusion and gravity (MHG) requires previous hydration of the plant material. In this work, ultrasound was used to speed up the hydration of guarana powder before MHG extraction and increase caffeine recovery. The humidification step was speeded up with ultrasound taking only 15 min over 60 min without ultrasound. Water and 50% (v/v) ethanol were evaluated as green solvents for humidification, with a higher concentration of caffeine obtained for the hydroalcoholic solution. Ultrasound pretreatment allowed guarana extracts from MHG with two times more caffeine for both solvents evaluated. Therefore, ultrasound can be used in the hydration step before MHG extraction to reduce time and increase caffeine recovery from guarana powder.