Navegando por Assunto "Biofilmes"

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Acesso aberto (Open Access)
Influência da velocidade de circulação do leite na adesão de Pseudomonas aeruginosa sobre aço inoxidável
(2009-09) FIGUEIREDO, Hamilton Mendes de; ANDRADE, Nélio José de; OZELA, Eliana Ferreira; MORALES, Gundisalvo Piratoba
The influence of the flow milk circulation in the bacterial adhesion of Pseudomonas aeruginosa was evaluated by simulation tests through a circuit model of milk processing. The circuit is composed of a tubulation of stainless steel AISI 304, with 1.9 cm of diameter, 5.8 m of length and a tank of 25 L used as the reservoir of the product and sanitizer solutions. The reservoir was coupled to a centrifugal bomb of ½ HP to impel the food or sanitizer solutions for the system equipped with 90º and T cylindrical stainless steel specimens. The speed of circulation values were 0.5, 1.0 and 1.5 m.s–1, corresponding to turbulent flow with number of Reynolds 14.000, 28.000 and 42.000, respectively. When flow of 0.5 m.s–1 was used 10.7% the cells remained adhered, however at the speed values of 1.0 and 1.5 m.s–1 the adhesion percentages were 5.36 and 4.9%, respectively. These findings indicate a lower removal rate of adhered cells as flow decreases allowing higher number of bacteria to adhere to the production line, which can favor the biofilm formation.
Acesso aberto (Open Access)
Staining of esthetic brackets by plaque disclosing solutions
(2014-06) ISMAEL, Luiza Novelino Acatauassú; NUNES, Mauro de Amorim Acatauassú; NUNES, Ana Maria Novelino Acatauassú; MOTTA, Rogério Heládio Lopes; DEMASI, Ana Paula Dias; FLÓRIO, Flávia Martão
AIM: To evaluate the staining of esthetic orthodontic brackets by plaque disclosing solutions. METHODS: Two types of brackets manufactured by GAC/DENTSPLY(r) were evaluated: ceramic (n=30) and polycarbonate (n=30). The brackets were divided into 6 groups. Two control groups (n=6) were immersed in absolute ethanol: GI - ceramic brackets and GII - polycarbonate brackets. Four experimental groups (n=12) were immersed in different plaque disclosing solutions: GIII (ceramic brackets) and GIV (polycarbonate brackets) were immersed in Replak(r); GV (ceramic brackets) and GVI (polycarbonate brackets) were immersed in Replasul "S"(r). Relative quantitative analysis of the influence of plaque disclosing tablets on bracket staining was performed using reflectance spectrophotometry of stain deposition. Exploratory analysis of the data was performed using Analysis of Variance (ANOVA) in a 2x2 factorial setup (bracket x immersion) with additional treatments (controls). RESULTS: The results demonstrated that the ceramic brackets presented the highest amount of staining when Replasul "S"(r) was used (pd"0.05). However, when Replak(r) was used, no statistically significant difference was found in comparison with the control group (p>0.05). For polycarbonate brackets, staining was detected for both disclosing solutions (p>0.05). CONCLUSIONS: The disclosing solutions caused stain formation on polycarbonate brackets and, under the tested conditions, use of Replak(r) on ceramic brackets did not cause staining.