Recurrent aphthous stomatitis (RAS) is a common disease in the oral cavity characterized by recurrent ulcers (RU). Usually, these cause acute pain without definitive treatment. The present study determines the efficacy of non-thermal plasma (NTP) for treating RU. NTP is applied to the patient’s RU using a radiofrequency generator connected to a point reactor. The power density applied to the ulcer is 0.50 W/cm², less than 4 W/cm², which is the maximum value without biological risk. Each patient received two treatments of three minutes each and spaced 60 min apart at a distance of 5 mm from the RU. From a sample of 30 ulcers in patients treated for RU with an average age of 37 years, they stated that the pain decreased considerably and without the need for ingestion of analgesics and antibiotics. Regeneration took place in an average of three days. The NTP proved to be an excellent therapeutic alternative for the treatment of RU since it has a rapid effect of reducing pain and inflammation, as well as adequate tissue regeneration.

Non-thermal plasmas (NTPs), known as cold atmospheric plasmas (CAPs), hold great potential for diverse medical applications, including dentistry. However, traditional linear and rigid dielectric barrier discharge reactors used for NTP generation encounter limitations in accessing oral cavities and root canals. To address this issue, we have developed an innovative NTP reactor featuring an angled end for improved accessibility. The central copper electrode, with a 0.59 mm diameter and adjustable length for desired angulation, is coated with zircon powder (ZrSiO₄) to ensure stable NTP generation. This central electrode is housed within a stainless steel tube (3 mm internal diameter, 8 mm external diameter, and 100 mm length) with a 27° angle at one end, making it ergonomically suitable for oral applications. NTP generation involves polarizing the reactor electrodes with 13.56 MHz radio frequency signals, using helium gas as a working medium. We introduce plasma-treated water (PTW) as an adjunctive therapy to enhance biofilm eradication within root canals. A synergistic approach combining NTP and PTW is employed and compared to the gold standard (sodium hypochlorite, NaOCl), effectively neutralizing Enterococcus faecalis bacteria, even in scenarios involving biofilms. Moreover, applying NTP in both gaseous and liquid environments successfully achieves bacterial inactivation at varying treatment durations, demonstrating the device’s suitability for medical use in treating root canal biofilms. The proposed NTP reactor, characterized by its innovative design, offers a practical and specific approach to plasma treatment in dental applications. It holds promise in combatting bacterial infections in root canals and oral cavities.

Chlorobenzene (CB) is a toxic compound and is broadly used as a raw material for phenol, solvents, and agrochemical products, among other substances. CB being a very lightly soluble compound in water (~ 0.450 mL/L) is highly volatile, and it can be found in both liquid and gas phases. In this paper, the treatment of CB was carried out in an aqueous solution assisted by nonthermal plasma (NTP) generated by a dielectric barrier discharge. NTP was utilized as a generator, producing active species for the treatment of CB in both liquid and gas phases, attaining high degradation efficiencies >95% and using a low electric power consumption <20 W. Energy efficiencies of CB removal in kg/kWh were estimated, and relatively high values ~ 0.5 kg/kWh were obtained with a low-energy consumption. Attained degradation efficiencies were determined using gas chromatography and mass spectrometry. Optical emission spectroscopy study was conducted to determine the gas temperature during experimentations. Thus, the estimated magnitude was lower than 110 °C in overall cases. Meanwhile, the resulting excitation temperature was near to 0.2 eV. This magnitude is in the range of typical temperatures for similar NTP devices.

The scarcity and contamination of water, aggravated by the effects of Climate Change, endanger the food supply, cause health problems to humans, and are a critical concern. New research has been carried out to improve the quality of water used in the agricultural sector. One of them is the technology of non-thermal plasma (NTP) generated by corona discharges using air as a working gas. In this study, the NTP is applied directly and causing the activation to three water sources: potable, wastewater from poultry farming, and rain, on the legume “lentil.” The results show that the NTP applied to the different water conditions modifies the legume structure, obtaining a better germination and growth rate. In particular, it found that the best condition to stimulate the plant structure growth is using wastewater from poultry activities, which NTP activates. Likewise, it identified the internalization of pathogenic microorganisms such as Escherichia coli and Salmonella typhimurium since the early development of the plant. The bacteria reduction after NTP application is detected due to the effect of the reactive species generated by the NTP. The NTP application for water activation can represent an alternative to solve the demand for food since the development of the structures of legumes, particularly of lentils, is promoted.

Objective: an innovative non-thermal plasma (NTP) system constituted by a radiofrequency (RF) power generator directly coupled to a treatment probe is described and characterized. This system is intended to be applied as a medical device for therapeutic treatments. Methods: electrical characterization of the radiofrequency power generator supplying the treatment probe was performed. Meanwhile, generated NTP was optically analyzed. Obtained data were studied to establish the safety profile of plasma application on heat sensitive matter. Results: the NTP system was validated through bacterial deactivation trials, as well as, of being capable of deactivating carcinogenic cells. Besides promoting and accelerating wound closure in vivo performed in mice, demonstrating faster healing than that done with conventional treatments. Conclusion: the NTP system's characterization is an essential stage to determine the adequate application of the generated plasma over organic media. The therapeutic benefits of the NTP system were proved by the development of in vivo experiences involving laboratory mice. Significance: the generated NTP interacts with surrounding air particles producing reactive oxygen and nitrogen species, which, exhibit bactericidal and antiseptic effects due to their strong biochemical reactivity; functioning like critical mediators in animal physiology and promoting wound healing processes. These properties make the NTP system a feasible technology intended for therapeutic treatments.