Effect of a Toothpaste for Sensitive Teeth on the Sensitivity and Effectiveness of In-office Dental Bleaching: A Randomized Clinical Trial.

OBJECTIVES: The present study aimed to evaluate the desensitizing effect of toothpaste for sensitive teeth on patient tooth sensitivity and on bleaching efficacy of the 38% hydrogen peroxide bleaching agent used for in-office bleaching compared to a regular toothpaste in a randomized clinical trial. METHODS AND MATERIALS: Forty-eight patients having maxillary right central incisors with darkness greater than A1 were selected for the present double-blind randomized clinical trial. Patients were randomly allocated into two groups: the placebo group, which used regular toothpaste, and the experimental group, which used sensitivity toothpaste. The intervention consisted of applying toothpaste with the aid of an individual tray for a period of 4 minutes daily, starting one week before the first bleaching session and interrupting use immediately after the second session. After allocation to one of the groups, individuals received in-office dental bleaching with a 40-minute application of 38% hydrogen peroxide for two sessions with an interval of one week. The incidence and intensity of sensitivity were assessed using a visual analogue scale and a numeric analogue scale. Sensitivity was measured immediately before each session, 1 hour, 24 hours, and 48 hours after each bleaching session and four weeks after the second bleaching session. Tooth shade was evaluated using a spectrophotometer and by comparison with the VITA Classical Shade Guide (Vita Zahnfabrik, Bad Säckingen, Germany). Tooth shade was evaluated before the first bleaching session, one week after the first bleaching session, one week after the second bleaching session and four weeks after the second bleaching session. Participants and professionals who performed the bleaching, shade, and sensitivity assessments were blinded to the group of patients they were treating or assessing. For the incidence of hypersensitivity, the results were evaluated by comparing the groups at different evaluation times with the Mann-Whitney test for comparison between groups, the Friedman test for repeated measures, and the Tukey test for comparison of times. Shade change on the guide was analyzed using the Mann-Whitney test for comparison between groups and the Wilcoxon test for comparison between times. Shade change by the spectrophotometer was analyzed using the t-test for comparison between groups and the paired t-test for comparison between times. All analyses were performed with a significance level of 5%. RESULTS: There was no difference in the pattern of dental hypersensitivity between groups. For all shade measures, there was no difference between the bleaching results, and no statistically significant difference was observed between the study groups. CONCLUSION: The use of arginine-based desensitizing toothpaste did not interfere with the bleaching ability of hydrogen peroxide and was not effective in reducing the sensitivity caused by in-office tooth bleaching.

Bioremediation of trace organic compounds found in precious metals refineries' wastewaters: a review of potential options.

Platinum group metal (PGM) refining processes produce large quantities of wastewater, which is contaminated with the compounds that make up the solvents/extractants mixtures used in the process. These compounds often include solvesso, beta-hydroxyxime, amines, amides and methyl isobutyl ketone. A process to clean up PGM refinery wastewaters so that they could be re-used in the refining process would greatly contribute to continual water storage problems and to cost reduction for the industry. Based on the concept that organic compounds that are produced biologically can be destroyed biologically, the use of biological processes for the treatment of organic compounds in other types of waste stream has been favoured in recent years, owing to their low cost and environmental acceptability. This review examines the available biotechnologies and their effectiveness for treating compounds likely to be contained in precious metal extraction process wastewaters. The processes examined include: biofilters, fluidized bed reactors, trickle-bed bioreactors, bioscrubbers, two-phase partitioning bioreactors, membrane bioreactors and activated sludge. Although all processes examined showed adequate to excellent removal of organic compounds from various gaseous and fewer liquid waste streams, there was a variation in their effectiveness. Variations in performance of laboratory-scale biological processes are probably due to the inherent change in the microbial population composition due to selection pressure, environmental conditions and the time allowed for adaptation to the organic compounds. However, if these factors are disregarded, it can be established that activated sludge and membrane bioreactors are the most promising processes for use in the treatment of PGM refinery wastewaters.

Septicemia caused by Vibrio cholerae O1 biotype El Tor, in São Paulo, Brazil.

We reported a case of septicemia by Vibrio cholerae O1, in São Paulo, Brazil. A 70-year-old male patient, living in an urban area, entered the emergency service having sepsis, dying 12 hours later. Blood culture was positive for Vibrio cholerae O1. This is the first case of bacteremia by Vibrio cholerae O1 reported in South America.

Carbapenem-resistant Enterobacteriaceae on a cardiac surgery intensive care unit: successful measures for infection control.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) cause surgical site infections (SSIs) in intensive care units (ICUs). This study aimed to evaluate the impact of intervention and control measures to reduce CRE colonization and infection rates among patients in the ICU of a cardiac surgery hospital following a CRE outbreak. METHODS: An observational study of the pre- and postintervention status of a cohort of colonized or infected patients in the postoperative adult cardiac surgery ICU was performed between April 2013 and December 2014. As well as the usual measures of screening and cohort nursing, the control measures were enhanced during the intervention period by providing alcohol gel at the bedside, daily bathing with no-rinse 2% chlorhexidine-impregnated wash cloths, and disinfection of surfaces around the patient three times per day. RESULTS: The rates of CRE colonization (P<0.001), primary central-line-associated bloodstream infections (P<0.002) and SSIs (P< 0.003) decreased significantly during the postintervention period. CONCLUSION: The implemented measures were effective in controlling colonization and infection with CRE in the cardiac surgery ICU.

Hydrogen sulphide removal by activated sludge diffusion.

Odours from wastewater treatment plants comprise a mixture of various gases, of which hydrogen sulphide (H2S) is the main constituent. Microorganisms commonly found in wastewater can degrade sulphurous compounds. Therefore, the use of activated sludge (AS) for odour control offers an alternative to traditional waste gas treatment processes, such as biofilters, bioscrubbers and biotrickling filters, both in practical terms (use of existing facilities) and economically (minimal capital cost). The performance of AS diffusion as a bioscrubber for removing H2S at concentrations at 25, 75 and 150 ppmv was evaluated. Pilot-scale trials were undertaken using parallel 60-L aeration tanks and 20-L clarifier reactors at the Bedford Sewage Treatment Works, Carington, UK. Olfactometry measurements were also carried out to determine whether there was any increase in odour concentration owing to H2S diffusion. Hydrogen sulphide removal rates of 100% were obtained, with no noticeable increase in odour concentration throughout the trials as measured by olfactometry. Odour concentration was highest at the beginning of the trials and lowest during the high H2S dosing period, with similar values being obtained for test and control. It was concluded that AS diffusion is an effective bioscrubber for the removal of H2S odour.

Characterization of Thiobacillus thioparus isolated from an activated sludge bioreactor used for hydrogen sulfide treatment.

AIMS: To compare Thiobacillus thioparus population dynamics in a control and a test activated sludge (AS) bioreactor, used for hydrogen sulfide (H(2)S) degradation. METHODS AND RESULTS: Denaturing gradient gel electrophoresis (DGGE) was used to confirm the presence of T. thioparus, and real-time PCR was used to quantify the level of this bacterium in the AS samples. The DGGE analysis showed a band for T. thioparus in all samples, with the band being more prominent in the test sample with H(2)S diffusion. It also showed that although a change occurred in the diversity of the microbial population in the test sludge after 6 weeks of H(2)S diffusion, the microbial community structure of the test and control was still similar. Thiobacillus thioparus-specific PCR primers confirmed that 50% of the isolates from both the test and control bioreactors were T. thioparus. The thiobacilli population became more efficient at degrading the diffused H(2)S. This increase in efficiency was confirmed by a significant increase in the number of isolates from the test sludge compared with those from the control sludge, when they were grown in a thiosulfate-rich liquid medium. CONCLUSIONS: It was concluded that the use of AS process for H(2)S removal encourages the population of T. thioparus to increase even at times when the total biomass concentration shows a decrease. SIGNIFICANCE AND IMPACT OF THE STUDY: The research results give an insight into the dynamics of the microbial population in an AS pilot plant used in a dual role, to treat the wastewater and H(2)S.

Direct bonding to porcelain.

Orthodontic brackets were bonded to 180 faces of 45 porcelain cubes that were divided into three groups according to their surface preparation. In group I, the glaze had been removed with a sandpaper disk, whereas in group II, it was maintained. A solution of acidulated phosphate fluoride (APF) gel was applied to the samples in groups I and II for 5 minutes after pumicing. In group III, the glaze had been removed with a coarse diamond bur. Each group was further divided into four subgroups, depending on whether a priming agent had been used, and the type of composite used to bond the brackets. Shear force was used to debond the brackets, and the results showed that the APF solution was unable to provide enough retention on porcelain surface to bond brackets. Mechanical retention, obtained with a coarse diamond bur, was necessary to increase bond strength, which can be further improved by chemical bonding, with a silane priming agent. Therefore bonding to porcelain is clinically possible and is an acceptable procedure in orthodontic treatment.

Efeitos da obesidade na distribuição de pressão plantar em crianças / Effects of obesity on plantar pressure distribution in children

OBJETIVO: O estudo teve como objetivo determinar se há diferenças na distribuição de pressão plantar estática e dinâmica entre crianças obesas e eutróficas. MÉTODO: Foram avaliadas vinte crianças, divididas em dois grupos (grupo de obesos e grupo de eutróficos), com idades entre nove e onze anos. As avaliações incluíram medidas das variáveis de pressão plantar na postura ereta e na marcha por meio do sistema Pedar (Novel GMbH). RESULTADOS: Constatou-se que as crianças obesas apresentaram maiores áreas de contato, picos de pressão, pressões médias máximas e integrais pressão-tempo, quando comparadas às eutróficas, com diferenças significativas, principalmente nas regiões do médio-pé e antepé. CONCLUSÕES: As diferenças observadas entre os grupos indicam que crianças obesas podem apresentar modificações importantes nos pés em função da sobrecarga excessiva e repetitiva à qual estão expostas, aumentando o risco para o desenvolvimento de lesões e patologias nos pés. Portanto, é necessário que programas de intervenção sejam implantados a fim de interferir também na progressão de problemas de natureza estrutural e funcional relacionados à obesidade.

OBJECTIVE: The aim of this study was to determine whether there were differences in static and dynamic plantar pressure distribution between obese and non-obese children. METHOD: Twenty children aged from nine to eleven years were assessed and divided into two groups (obese and non-obese groups). The assessments included measurements of plantar pressure variables while standing and walking, by means of the Pedar System (Novel GMbH). RESULTS: The obese children presented greater contact area, peak pressure, maximum mean pressure and pressure-time integral, in comparison with the non-obese children, with significant differences particularly in the midfoot and forefoot areas. CONCLUSION: The differences observed between the groups indicated that obese children may present significant modifications to their feet because of the excessive and repetitive loads that they are exposed to, which increases the risk of developing foot injuries and pathologies. It is suggested that there is a need to implement intervention programs with the aim of interfering with the progression of obesity-related problems from a structural and functional perspective.

Septicemia caused by Vibrio cholerae O1 biotype El Tor, in São Paulo, Brazil

We reported a case of septicemia by Vibrio cholerae O1, in São Paulo, Brazil. A 70-year-old male patient, living in an urban area, entered the emergency service having sepsis, dying 12 hours later. Blood culture was positive for Vibrio cholerae O1. This is the first case of bacteremia by Vibrio cholerae O1 reported in South America.