Effectiveness Of Disinfection Treatments Research Articles

Effect of Ultraviolet Radiation on Candida albicans Biofilm on Poly(methylmethacrylate) Resin.

To investigate the effect of 254-nm ultraviolet light on the viability of Candida albicans biofilm on poly(methylmethacrylate). Poly(methylmethacrylate) specimens (1 cm × 1 cm × 1 mm) were placed in 6-well culture plates. Each well contained 8 ml of 104 colony forming units/milliliter of C. albicans ATCC90028 and Sabouraud dextrose broth. Plates were incubated at 37°C for 24 hours. Specimens were then divided into 11 groups (n = 4): no treatment control groups, 3.8% sodium perborate immersion for 5 minutes (PP5m) and for 12 hours (PO12h), and 6 groups exposed to ultraviolet light for 5, 15, 30, 60, 120 or 300 seconds separately using UVP XX-15S series lamps. After sonication, cell suspensions were plated, and colony-forming units were counted. The relationship between survival of C. albicans and ultraviolet light irradiation energy exposure was analyzed and compared to the survival of sodium perborate groups. The effect of disinfection treatments and ultraviolet light energy exposure on C. albicans survival was analyzed with ANOVA (alpha = 0.05). There was a significant decrease in C. albicans survival with increasing ultraviolet light energy exposure (p = 0.00001, p < 0.05) Survival vs. immersion exposure time analysis of chemical disinfection showed no survival of C. albicans in groups PP5m and PO12h. C. albicans in the UV 300s group with energy of 210 mJ/cm2 (71 CFU/ml) showed a statistical difference from that of two chemical immersion groups (PP5m, PO12h = 0 CFU/ml) (p = 0.00001, p < 0.05). Ultraviolet 254 nm irradiation demonstrated a significant inhibition of C. albicans survival on poly(methylmethacrylate) samples. Ultraviolet light exposure of 300 seconds inhibited the survival of C. albicans close to the level of 3.8% sodium perborate treatment.

Peculiarities of Disinfection of Microbiological Safety Cabinets and Premises of Virological Laboratories when Carrying out Works with the Smallpox Virus

Objective. Applying microbiological method to determine the effectiveness of disinfection treatments with formaldehyde fumigation of the hidden cavities and the reverse side of the microbiological safety cabinet filters (MSC) located in the “infectious” areas of an isolated to maximum extent laboratory. Evaluation of the effectiveness of experimental unit for automation of the formaldehyde treatment of laboratory premises. Materials and methods. Assessment of effectiveness of disinfection treatments of MSCs and the premises of virological laboratory was carried out using cambric test objects contaminated with the spore-forming test culture of B. thuringiensis. Results and discussion. The disinfection time sufficient for the complete inactivation of particularly dangerous pathogenic microorganisms potentially located in hidden cavities and on the back side of microbiological safety cabinet filters, placed in the “infectious” zone of the most isolated laboratory has been determined experimentally. As a result of the studies, it was possible to achieve complete inactivation of the spore-forming test microorganism located on test objects situated in hidden cavities and hardly accessible places of MSC at concentration of 1·106 cells/cm3 only with disinfection time equal to 24 hours. Effective disinfection of test objects contaminated with B. thuringiensis spore-forming test culture, placed in hard-toreach places and on the back of the equipment in a boxed virological room, using an experimental plant producing gaseous formaldehyde, was possible only when formalin was used in a concentration of 40 ml/m3 of the room. It was established that the amount of formalin required to achieve 100% efficiency of the disinfection treatment of the virological boxed room using an experimental unit producing gaseous formaldehyde depends on the operating mode of the general supply and exhaust ventilation, the configuration of the laboratory room, and the furnishing with laboratory and engineering equipment.

Image processing as a tool for evaluating denture adhesives removal techniques

ABSTRACTDenture adhesives are widely used, but patients express difficulty in removing it. Image processing was already using to evaluate the effectiveness of disinfection treatments. The objective of the present study is to evaluate, under image processing, the adhesive removal protocols recommended by the adhesive manufacturers. Thirty pink acrylic discs were made, and denture adhesives were applied to their outer surface. Afterwards, the adhesive was immersed in a green food-colouring agent for 30 s. The total surface area and pigmented areas were measured using an image processing software (Image Tool 3.0). After each measurement, the adhesive removal protocols were performed. Samples were divided into two groups. In group 1 discs were brushed with a denture brush and water, with three longitudinal movements. In group 2 the discs were submerged in water with a denture cleansing tablet for 3 min and brushed. Statistical analyses were performed (p = 0.05). In our study, water brushing provided less effective results. The combination of immersion in an alkaline peroxide solution followed by brushing, despite continuing to provide low efficacy, presents much better results. Image processing is a valid tool and an objective means to measure the efficacy of different techniques for dentures.

Effect of Disinfection, Packaging, and Storage Environment on the Shelf Life of Mango

The effect of disinfection treatments, packaging, and storage environment on the quality of mango fruits (Mangifera indica L.) was studied at Dire Dawa, Ethiopia over a storage period of 28 days. Mango fruits were assessed for physiological weight loss (PWL), total soluble solids (TSS), titratable acidity (TA), ascorbic acid (AA), and marketability. The evaporative cooling maintained the temperature between 14·33 and 19·26 °C and the relative humidity between 70·15% and 82·4% during the storage period. The shelf life of mangoes kept in the evaporative cooling unit was increased from 3 to 28 days, compared to storage at ambient conditions. The Storage temperature greatly (probability, P