Assessment of a Biosafety Device to Control Contamination by Airborne Transmission during Orthodontic/Dental Procedures.

During the COVID-19 pandemic, dental professionals have faced high risk of airborne contamination between dentists, staff, and patients. The objective of this study was to evaluate the effect of an individual biosafety capsule in dentistry (IBCD) on reducing the dispersion of droplets and aerosols during orthodontic treatment and evaluate the clinician and patient's perception of using the IBCD. For the in-vitro part of the study, aerosol quantification was performed with and without the IBCD, using a nonpathogenic bacterial strain and viral strain in the reservoir and high-speed dental handpiece. Petri dishes with MRS agar were positioned from the head of the equipment at distances of 0.5, 1, and 1.5 m. After 15 minutes of passive aerosol sampling, the dishes were closed and incubated using standard aerobic conditions at 37°C for 48 hours to count colony forming units (CFUs). For the clinical part of the study, a questionnaire was sent to clinicians and patients to understand their perception of orthodontically treat and receive treatment using the barrier. The use of IBCD showed an effective means to reduce the dispersion of bacterial and viral contamination around 99% and 96%, respectively, around the main source of aerosol (p < 0.05). Clinical results showed a 97% bacterial reduction during patient's consultations (p < 0.05). The vast majority of clinicians and patients understand the importance of controlling the airborne dispersion to avoid contamination.

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

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.

A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips.

Strategies to return to dental practice in pandemic times is a new challenge due to the generation and spread of potentially contaminated dispersion particles (PCDP) that may contain the SARS-CoV-2, the etiological factor of the COVID-19 disease. Due to the significant dispersion of PCDP in the dental environment, the use of equipment such as ultrasonic tips have been inadvisable during the pandemic. Several clinical procedures, however, benefit from the use of such equipment. Thus, using a microbial dispersion model of PCDP, the aim of this study was to compare the dispersion caused by the dental drill (DD) an ultrasonic tip (UT) alone and the UT coupled with a Spray control (SC) device. The DD, UT (with or without the SC) were activated for one minute having had the water from the reservoir replaced with a suspension of Lactobacillus casei Shirota (1.5 x 108 CFU/mL). Petri dishes containing MRS agar were positioned at 50cm, 100cm and 150cm from the headrest of the dental chair at different angles (0 degree and 90 degrees). At 50 cm, the mean CFU (standard deviation) of L. casei Shirota was 13554.60 (4071.03) for the DD, 286.67 (73.99) for the US (97.89% reduction), and 4.5 (0.58) CFU for the UT-SC (p < 0.0001), establishing a further 98.43% reduction between UT and UT with SC. The UT with SC model proved effective in reducing dispersion from the UT, endorsing its use as an additional strategy to reduce PCDP in the dental environment in times of pandemic.

Individual biosafety barrier in dentistry: an alternative in times of covid-19. Preliminary study

ABSTRACT The return to dental practice in pandemic times is a new challenge due to the generation and dispersion of droplets and aerosols that may contain the SARS-CoV-2 virus, the etiological agent of covid-19. In the last months some droplet and aerosol containment strategies have been circulating on the internet, however, until now there is no evidence in the literature to prove the effectiveness of such barriers. Thus, using a microbial dispersion model with the fast handpiece, the aim of this preliminary study was to compare the dispersion caused by the the dental drill (DD) alone or in association with an individual biosafety barrier (IDBD / DD), which consisted of a layer of PVC film combined to a layer of polypropylene mounted on a frame. The dental drill was activated for one minute having had the water from the reservoir been replaced with a suspension of Lactobacillus casei Shirota. Petri dishes containing MRS agar were positioned at 50, 100 and 150 cm from the headboard of the dental chair at different angles (90 and 0 degrees). At 50 cm, the mean (standard deviation) of L. casei Shirota for DD was 13,554.59 (493.48) CFU, while for IDBD / DD was 570.67 (60.54) CFU (p &lt;0.0001), establishing a 96% reduction. Considering these preliminary results, the individual biosafety barrier proved effective in reducing dispersion from the dental drill in this study model, which suggests that this barrier may be a viable option to optimize biosafety in the dental environment. RESUMO A retomada às atividades odontológicas em tempos de pandemia tem sido um desafio devido à geração e dispersão de gotículas e aerossóis que podem conter o vírus SARS-CoV-2, agente etiológico da covid-19. Nos últimos meses algumas estratégias de contenção de gotículas e aerossóis tem circulado pela internet, mas a eficácia destas barreiras ainda não apresenta um bom nível de evidência na Literatura. Desta forma, e utilizando um modelo de dispersão microbiana, o objetivo deste estudo preliminar foi comparar a dispersão da alta rotação (AR) sem ou associada a uma barreira individual de biossegurança odontológica (AR / BIBO) que consiste em um bastidor acoplado ao filme de PVC e TNT. A turbina da alta rotação foi ativada durante um minuto em uma solução de Lactobacillus casei Shirota, a qual havia sido previamente acrescentada no reservatório de refrigeração de um equipamento odontológico, e placas de petri contendo ágar MRS foram posicionadas a partir do apoio de cabeça de uma cadeira odontológica nas distâncias de 50, 100 e 150 cm em diferentes ângulos (90 e 0 graus). Na distância de 50 cm, a média (desvio padrão) de L. casei Shirota para AR foi de 13.554,59 (493,48) UFC, enquanto a associação AR/BIBO foi de 570,67 (60,54) UFC, estabelecendo uma redução de 96% (p&lt;0,0001). Considerando estes resultados preliminares e o modelo de estudo utilizado, a barreira individual de biossegurança odontológica se mostrou eficiente em reduzir a dispersão da turbina de alta rotação, o que sugere que o seu uso pode ser uma alternativa para a melhoria da biossegurança em ambiente odontológico.

Individual biosafety barrier in dentistry: an alternative in times of covid-19. Preliminary study

ABSTRACT The return to dental practice in pandemic times is a new challenge due to the generation and dispersion of droplets and aerosols that may contain the SARS-CoV-2 virus, the etiological agent of covid-19. In the last months some droplet and aerosol containment strategies have been circulating on the internet, however, until now there is no evidence in the literature to prove the effectiveness of such barriers. Thus, using a microbial dispersion model with the fast handpiece, the aim of this preliminary study was to compare the dispersion caused by the the dental drill (DD) alone or in association with an individual biosafety barrier (IDBD / DD), which consisted of a layer of PVC film combined to a layer of polypropylene mounted on a frame. The dental drill was activated for one minute having had the water from the reservoir been replaced with a suspension of Lactobacillus casei Shirota. Petri dishes containing MRS agar were positioned at 50, 100 and 150 cm from the headboard of the dental chair at different angles (90 and 0 degrees). At 50 cm, the mean (standard deviation) of L. casei Shirota for DD was 13,554.59 (493.48) CFU, while for IDBD / DD was 570.67 (60.54) CFU (p <0.0001), establishing a 96% reduction. Considering these preliminary results, the individual biosafety barrier proved effective in reducing dispersion from the dental drill in this study model, which suggests that this barrier may be a viable option to optimize biosafety in the dental environment. RESUMO A retomada às atividades odontológicas em tempos de pandemia tem sido um desafio devido à geração e dispersão de gotículas e aerossóis que podem conter o vírus SARS-CoV-2, agente etiológico da covid-19. Nos últimos meses algumas estratégias de contenção de gotículas e aerossóis tem circulado pela internet, mas a eficácia destas barreiras ainda não apresenta um bom nível de evidência na Literatura. Desta forma, e utilizando um modelo de dispersão microbiana, o objetivo deste estudo preliminar foi comparar a dispersão da alta rotação (AR) sem ou associada a uma barreira individual de biossegurança odontológica (AR / BIBO) que consiste em um bastidor acoplado ao filme de PVC e TNT. A turbina da alta rotação foi ativada durante um minuto em uma solução de Lactobacillus casei Shirota, a qual havia sido previamente acrescentada no reservatório de refrigeração de um equipamento odontológico, e placas de petri contendo ágar MRS foram posicionadas a partir do apoio de cabeça de uma cadeira odontológica nas distâncias de 50, 100 e 150 cm em diferentes ângulos (90 e 0 graus). Na distância de 50 cm, a média (desvio padrão) de L. casei Shirota para AR foi de 13.554,59 (493,48) UFC, enquanto a associação AR/BIBO foi de 570,67 (60,54) UFC, estabelecendo uma redução de 96% (p<0,0001). Considerando estes resultados preliminares e o modelo de estudo utilizado, a barreira individual de biossegurança odontológica se mostrou eficiente em reduzir a dispersão da turbina de alta rotação, o que sugere que o seu uso pode ser uma alternativa para a melhoria da biossegurança em ambiente odontológico.