Effect of disinfectant solutions on a denture base acrylic resin.

The aim of this study was to evaluate the hardness, roughness and mass loss of an acrylic denture base resin after in vitro exposure to four disinfectant solutions. Forty specimens (Clássico, Brazil) were prepared and randomly assigned to 4 groups n = 10) according to the disinfectant solution: G1: control, stored in distilled water at 37 degrees C; G2: 1% sodium hypochlorite; G3: 2% glutaraldehyde; G4: 4% chlorhexidine. G2 to G4 were immersed for 60 minutes in the disinfectant solution. Measurements were carried out both before and after immersion in the solution. The surface was analyzed with a surface roughness tester (Surfcorder SE 1700 KOZAKALAB), a microdurometer FM-700 (Future Tech) and a scanning electron microscope (DSM 962-ZEISS). Loss of mass was determined with a digital weighing scale. After disinfection procedures, values were analyzed statistically. The acrylic denture base resin may be vulnerable to surface changes after in vitro immersion in the disinfectant solutions studied.

Gas phase photocatalytic bacteria inactivation using metal modified TiO2 catalysts

The present study describes the efficiency of heterogeneous photocatalytic reactor for the inactivation of three air born bacteria, Escherichia coli, Bacillus subtilis and Staphylococcus aureus using metal modified TiO2 photocatalysts and blacklight irradiation. The catalysts were prepared by photodeposition of silver, palladium or iron on commercial TiO2, immobilized on glass plates. X-ray photoelectron spectroscopy analysis was applied to determine the atomic percentage and species of each metal on the TiO2 surface, showing that 85% of silver, 73% of palladium and 45% of iron were present in metallic form on TiO2 surface. The plates were positioned on the inner lateral walls of a chamber through which the contaminated air flow passed for disinfection. Irradiation of bare TiO 2 resulted in 50% inactivation of E. coli while 41% and 35% inactivation of B. subtilis and S. aureus were obtained, respectively. When metal modified TiO2 was applied, the inactivation of B. subtilis was improved to 91% using Pd-TiO2 while of S. aureus was improved to 94% with Fe-TiO2, showing in this case no significant difference when compared to Ag-TiO2 and Pd-TiO2. In contrast, inactivation of E. coli was not significantly increased when metal modified TiO2 was used, ranging from 47% to 57%. © 2012 Elsevier B.V.

Effect of different disinfectants on the microhardness and roughness of acrylic resins for ocular prosthesis

Background: Ocular prosthesis materials should have specific properties for their indication and durability; therefore, it is important to investigate their physical behaviour when affected by several disinfectants. Objectives: This study evaluated the influence of different disinfecting solutions on the microhardness and surface roughness of acrylic resins for ocular prosthesis. Materials and Methods: Fifty samples simulating ocular prostheses were fabricated with N1 resin and colourless resin and divided (n = 10) according to the disinfectant used: neutral soap, Opti-free, Efferdent, 1% hypochlorite (HYC) and 4% chlorhexidine (CHX). Samples were stored in saline solution at 37°C and disinfected during 120 days. Both microhardness and roughness were investigated before, after 60 days and 120 days of disinfection and storage. Microhardness was measured using a microhardner and the roughness with a roughness device. Results: N1 resin showed lower microhardness when compared with colourless resin (p < 0.05). HYC and CHX groups exhibited the highest change of microhardness and roughness values (p < 0.05). An increase in roughness and reduction in microhardness of ocular acrylic resins were observed after both periods of disinfection and storage (p < 0.05). Conclusion: Both disinfection/storage periods affected the microhardness and roughness values of the samples. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

Effectiveness of disinfectants used in hemodialysis against both Candida orthopsilosis and C. parapsilosis sensu stricto biofilms

Biofilms have been observed in the fluid pathways of hemodialysis machines. The impacts of four biocides used for the disinfection of hemodialysis systems were tested against Candida parapsilosis sensu stricto and Candida orthopsilosis biofilms generated by isolates obtained from a hydraulic circuit that were collected in a hemodialysis unit. Acetic acid was shown to be the most effective agent against Candida biofilms. Strategies for effective disinfection procedures used for hemodialysis systems should also seek to kill and inhibit biofilms. Copyright © 2013, American Society for Microbiology. All Rights Reserved.

Determination of Total Nitrosamines in Vegetables Cultivated Organic and Conventional Using Diamond Electrode

Vegetables were analyzed for total N-nitrosamines (NAs) and the influence of disinfection processes was assessed. Differences in NAs found in cabbage, spinach, and broccoli were determined by square wave voltammetry using a boron-doped diamond electrode. Analysis of samples showed that all samples contained detectable levels of NAs but the results indicated that organic contained less than conventionally grown products. The sum of the total NAs was higher in the cabbage samples, ranging between 2.8-3.1 ppb and lower in broccoli samples at 0.2-1.1 ppb. The method described is simple, rapid, selective, and sensitive. The results suggested that the disinfection process affects the level of NAs, in this manner affecting the level of human exposure to NAs. © 2012 Springer Science+Business Media New York.

Histologic Characterization of Engineered Tissues in the Canal Space of Closed-apex Teeth with Apical Periodontitis

Introduction: The aim of this study was to investigate the capacity of endodontic regenerative procedures combining an induced blood clot, platelet-rich plasma (PRP), and bone marrow aspirate (BMA) to regenerate dental pulp in canine closed-apex necrotic teeth. Methods: Apical periodontitis was induced in 20 upper and lower premolars of 2 dogs. After biomechanical preparation, enlargement to a #60 file, and disinfection with a triantibiotic paste for 28 days, the roots were randomly assigned to 4 treatment groups: blood clot (BC), BC + PRP gel, BC + BMA gel, and BC + BMA/PRP gel. Negative controls were also included. After a 3-month follow-up period, the animals were killed. Results: Histologic analysis showed the presence of newly formed vital tissues (connective, cement-like, and bone-like tissue) in 23 of the 32 treated roots (71.87%). There was no statistically significant difference between the treatment groups. Conclusions: New vital tissues were formed and characterized as connective, cementum-like, or bone-like, but not as pulp-like tissue; PRP and/or BMA did not improve the tissue ingrowth. © 2013 American Association of Endodontists.

A photoelectrocatalytic process that disinfects water contaminated with Mycobacterium kansasii and Mycobacterium avium

Nontuberculous mycobacteria are resistant to conventional water treatment; indeed, they have been recovered from a wide variety of environmental sources. Here, we applied the photoelectrocatalytic technique using a Ti/TiO2-Ag photoanode to inactivate mycobacteria. For a mycobacteria population of 5 × 108 CFU mL-1, we achieved 99.9 and 99.8% inactivation of Mycobacterium kansasii and Mycobacterium avium with rate constant of 6.2 × 10-3 and 4.2 × 10-3 min-1, respectively, after 240 min. We compared the proposed method with the photolytic and photocatalytic methods. Using a mycobacteria population of 7.5 × 104 CFU mL-1, the proposed Ti/TiO2-Ag photoanode elicited total mycobacteria inactivation within 3 min of treatment; the presence of Ag nanoparticles in the electrode provided 1.5 larger degradation rate constant as compared with the Ti/TiO2 anode (1.75 × 10-2 for M. kansassi and 1.98 × 10-2 for M. avium). We monitored the degradation of the metabolites released during cellular lysis by TOC removal, sugar release, chromatography, and mass spectrometry measurements; photoelectrocatalysis and Ti/TiO2-Ag photoanodes furnished the best results. © 2013 Elsevier Ltd. All rights reserved.

Qualidade bacteriológica de águas de irrigação de hortas nos municípios Araraquara, Boa Esperança do Sul e Ibitinga, SP

Pós-graduação em Alimentos e Nutrição - FCFAR

Análise morfológica de cones de guta-percha submetidos a diferentes tratamentos de desinfecção e sua influência na microinfiltração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desinfecção da água utilizando aquecimento solar

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Comparação entre ágar e amido como agentes gelificantes na micropropagação de batata doce Ipomoea batatas (L.) Lam

Pós-graduação em Agronomia (Horticultura) - FCA

Estudo da eficiência da desinfecção solar de águas residuárias domésticas em reatores de diferentes colorações

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Avaliação qualitativa da água residuária de abatedouro de aves para fins de reúso em irrigação

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Influência do jejum e do cloro sobre a microbiologia e morfometria intestinal de frangos de corte durante o período pré-abate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dinâmica da contaminação fecal e uso do cloro na desinfecção da água oferecida a bezerras em propriedade leiteira

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)