Biosafety devices to control the spread of potentially contaminated dispersion particles. New associated strategies for health environments

Abstract

Dental procedures produce a large amount of spatter and aerosols that create concern for the transmission of airborne diseases, such as Covid-19. This study established a methodology with the objective of evaluating new associated strategies to reduce the risk of cross-transmission in a health environment by simulating spread of potentially contaminated dispersion particles (PCDP) in the environment. This crossover study, was conducted in a school clinic environment (4 clinics containing 12 dental chairs each). As a positive control group (without barriers), 12 professionals activated at the same time the turbine of dental drill, for one minute, with a bacterial solution (Lactobacillus casei Shirota, 1.5x108 CFU/mL), which had been added in the cooling reservoir of the dental equipment. In the experimental groups, the professionals made use of; a) an individual biosafety barrier in dentistry (IBBD) which consists of a metal support covered by a disposable PVC film barrier; b) a Mobile Unit of Disinfection by Ultraviolet-C, consisting of 8 UV lamps-C of 95W, of 304μW/cm2 of irradiance each, connected for 15 minutes (UV-C) and; c) the association between the two methods (IBBD + UV-C). In each clinic, 56 Petri dishes containing MRS agar were positioned on the lamps, benches and on the floor. In addition, plates were placed prior to each test (negative control group) and plates were also placed in the corridor that connects the four clinics. In the groups without barrier and IBBD + UV-C the passive air microorganisms in Petri dishes was also evaluated at times of 30, 60, 90 and 120 minutes after the end of the dental’s drill activation. The mean (standard deviation) of CFU of L. casei Shirota for the positive control group was 3905 (1521), while in the experimental groups the mean using the IBBD was 940 (466) CFU, establishing a reduction on average, of 75% (p<0.0001). For the UV-C group, the mean was 260 (309) CFU and the association of the use of IBBD + UV-C promoted an overall average count of 152 (257) CFU, establishing a reduction on average of 93% and 96%, respectively (p<0.0001). Considering these results and the study model used, the individual biosafety barrier associated with UV-C technology showed to be efficient strategies to reduce the dispersion of bioaerosols generated in an environment with high rate of PCDP generation and may be an alternative for the improvement of biosafety in different healthy environment.

Indoor Inactivation of SARS-CoV-2 Virus by Liquid Hyperoxygen

“…Even though the latter appears minimally in the radical aqueous blend, their presence significantly influences the virus’s susceptibility to IOL. Therefore, IOL’s potential as a disinfectant in real-world settings, such as households, hospitals, and clinics, is accentuated, especially when integrated with colorimetric sensors to confirm adequate disinfection levels, ensuring both efficacy and safety [ 33 , 34 ].…”

Reduction of aerosol dissemination in a dental area generated by high-speed and scaler ultrasonic devices employing the “Prime Protector”

“…Among the devices mentioned in the literature it is possible to find a plastic-coated metal frame, a protection chamber, a dome-shaped customized shield and some other aerosol containment devices [ 1 , 9 , 10 ]. Some of these physical barriers are associated with high suction systems, such as the one proposed by Teichert-Filho et al in 2020. and Suwandi et al in 2022 [ 11 , 12 ] while others do not consider this variable [ 1 , 9 , 13 ].…”