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Improving the air quality of indoor environments (IAQ) is of utmost importance to safeguard public health as people spend about 80–90% of their time indoor. Efficient Ultraviolet germicidal irradiation (UVGI) system represents a strategic and sustainable solution to protect from recurrent and new airborne pathogens. Here, we present a new approach to design highly efficient UVGI systems, which can be installed in existing Air Treatment Units (ATU) plants with minimal effort. The increased efficiency relies on the concept of an optical cavity, thanks to its shape and source position. The internal volume consists of a highly reflective cavity illuminated with UV-C lamps. Optical simulations permitted the variation of the parameters to maximize the internal irradiance and, thus, the performance. The sanitation efficacy of the system was assessed on a full-scale pilot system. Tests were carried out under normal operating conditions against various microorganisms showed an inactivation rate of > 99%. The benefits of such systems are triple and encompass economic, environmental, and societal aspects. Since the system requires little energy to operate, its application for air disinfection may yield significant energy savings and ensure a balance between energy sustainability and good IAQ.

Purpose: This randomised controlled study evaluated the effectiveness of an oral probiotic, Streptococcus salivarius M18 (SsM18), in children with black stains (BSs) in order to counteract their reformation.Materials and Methods: Fifty-eight children (aged 4-10 years) presenting with BSs were enrolled. They were randomly divided into two groups: group A (n = 29) included children who were given the test product containing SsM18 once a day for 3 months; group B (n = 29) included children who did not receive any treatment. Before beginning the study, all the children underwent professional removal of BSs. The assessment of BSs was done after 3 months (T1) and after 6 months (T2).Results: Four patients (1 belonging to group A and 3 to group B) were excluded from the study because they started antibiotic therapy. After 3 months (T1), BSs were detected in 6 of the 28 children (21.2%) from group A and in 13 out of the 26 (50%) children from group B (p < 0.05). After 6 months (T2), BSs were detected in 9 out of the 28 (32.1%) children from group A and in 14 of the 26 (53.8%) children from group B (p > 0.05).Conclusions: BSs formation in children could be prevented by administering S. salivarius M18. [ABSTRACT FROM AUTHOR]

Background: Pits and fissures sealing and modulation of oral microbiota through probiotics are important preventive measures against dental decays. The aim of this study was to investigate the antibacterial activity of the Embrace™ WetBond™ Pit and Fissure Sealant (Pulpdent, USA) and UltraSeal XT® Hydro™ (Ultradent, USA) against selected oral bacteria and probiotics.Methods: The antibacterial effect of both sealants was tested both through planktonic growth inhibition test - 96-well microtiter plates and agar disk diffusion assay containing light-cured Embrace™ and UltraSeal XT® against Streptococcus mutans and two oral probiotics (Streptococcus salivarius and Lactobacillus reuteri).Results: Embrace™ showed a stronger and broad activity against all the bacterial strains tested (P < 0.05) in planktonic growth inhibition test even at its lowest dose (10 μl), with inhibition rates higher than 90% in all cases. UltraSeal XT® Hydro™ showed a mild antibacterial activity against L. reuteri, with growth inhibition rates being 19% and 23% for 20 μl and 50 μl, respectively. Regarding agar disk diffusion test, both sealants showed exclusively an antibacterial activity by contact.Conclusions: According to these findings, it is recommended to carefully plan the timing for the administration of different preventive interventions, such as oral probiotics assumption and sealant application, to maximize their specific effectiveness. We suggest prescribing oral probiotics first and putting off the Embrace™ sealant application to the end of probiotic treatment. On the contrary, it is possible to administer L. reuteri simultaneously with the application of UltraSeal XT® since it elicits a minimal antibacterial action against this oral probiotic. [ABSTRACT FROM AUTHOR]