In Vitro Evaluation Of The Abrasiveness Of A Commercial Low-abrasive Dentifrice And An Experimental Dentifrice Containing Vegetable Oil

Toothpastes usually contain detergents, humectants, water colorant, fluoride and thickeners (e.g. silica). Tooth wear has a multi-factorial etilology and the use of abrasive dentifrices is related to abrasion of dental tissues during toothbrushing. This study evaluated in vitro the abrasiveness of a commercial silica gel low-abrasive dentrifice compared to an experimental dentifrice containing vegetable (almond) oil. Distilled water served as a control group. Acrylic specimens (8 per group) were submitted to simulated toothbrushing with slurries of the commercial dentifrice experimental dentifrice, almond oil and water in an automatic brushing machine programmed to 30,000 brush strokes for each specimen which is equivalent to 2 years of manual toothbrushing. Thereafter, surface roughness (Ra) of the specimens was analyzed with a Surfcorder SE 1700 profilometer. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant differences (p>0.05) in the surface roughness after brushing with water almond oil experimental dentifrice. The commercial dentifrice produced rougher surfaces compared to the control and abrasive free products (p<0.05). Further studies are necessary in confirm the potential benefits of using vegetable oil in toothpaste as an alternative in abrasives in an attempt to minimize the tooth wear caused by toothbrushing.72415261530Löe, H., Kleinman, D.V., (1986) Dental Plaque Control Measures and Oral Hygiene Practices, , Oxford: IRL Press;, 332pBueno, M.A.M., Toledo, S., Sallum, E.A., Nociti Junior, F.H., Influência da escovação dental orientada na redução do sangramento gengival, em áreas próximas a restauraç-tioes metálicas. (1998) Rev ABO Nac, 6, pp. 44-47Andrade Junior, A.C.C., Andrade, M.R.T.C., Machado, W.A.S., Fischer, R.G., Abrasividade de dentifrícios: Revisão de literatura. (1997) Rev Periodontia, 6, pp. 25-30Baxter, P.M., Davis, W.B., Jackson, J., Toothpaste abrasive requirements to control naturally stained pellicle (1981) J Oral Rebabil, 8, pp. 19-26Hefferren, J.J., Schemehon, B., Storek, A., Lerck, M., Li, N., Silica as a reference for laboratory dentifrice assessment methods: Multiple collaborative study (2007) J Clin Dent, 8, pp. 12-16Stookey, G., Muhler, J., Laboratory studies concerning the enamel and dentin abrasion properties of common dentifrice polishing agents (1968) J Dent Res, 47, pp. 524-532Glantz, P.O., Larsson, L.A., Surface roughness of composite resins before and after toothbrushing (1972) Acta Odont Scand, 30, pp. 335-347Prampero, A.L., Lara, E.H.G., Tastes, R.C.A., Ogasawara, M.S., Panzeri, H., (1992) Relação das escovas com dentifrícios: Estudo da interação de escovas dentais de diferentes tipos de cerdas com preparações básicas para dentifr-acicios, 40, pp. 298-302. , RGOSlop, D., Rooij, J.F., Arends, J., Abrasion of enamel. 1. An in vitro investigation (1983) Caries Res, 17, pp. 242-248Heath, J., Wilson, J., Abrasion of restorative materials by toothpaste (1976) J Oral Rehabil, 3, pp. 121-138Patrão FGD, Sinhoreti MAC, Consani S, Correr Sobrinho L, Milan FM. Avaliação in vitro da rugosidade produzida por escovas dentais e dentifríicios em resina para base de prótese. Rev Fac Odontol Univ Passo Fundo. 19983: 7-14Correr Sobrinho, L., Francisco, M.U., Consani, S., Sinhoreti, M.A.C., Consani, R.L.X., Influência da escovação na rugosidade de superfície de materiais restauradores estéticos. (2001) PGR Pós-Grad Rev Fac Odontol São Jose dos Campos, 4, pp. 47-55Lara, E.H.G., Panzeri, H., Ogasawara, M.S., Ciampo, J.O.D., Moraes, J.T., Avaliação laboratorial dos dentifrícios cornerciais. (1996) Rev ABO Nac, 4, pp. 176-180Addy, M., Goodfield, S., Harrison, A., The use of acrylic to compare the abrasivity and stain removal proprieties of toothpastes (1991) Clin Mater, 7, pp. 219-225Addy, M., Evaluation of clinical trials of agents and procedures to prevent caries and periodontal disease: Choosing products and recommending procedures (1995) Int Dent J, 45, pp. 185-196Shaw, L., al-Dlaigan, Y.H., Smith, A., Childhood asthma and dental erosion (2000) J Dent Child, 67, pp. 102-106Al-Dlaigan, Y.H., Shaw, L., Smith, A.J., Is there a relationship between asthma and dental erosion? A case control study (2002) Int J Paediatric Dent, 12, pp. 189-200Aguiar, A.A.A., Moraes Filho, F.C., A interferência do óleo vegetal na aderência da placa bacteriana dental. (1998) Rev Cienc Odontol, 1, pp. 21-25Aguiar, A.A.A., Saliba, N.A., Toothbrushing with vegetable oil: A clinical and laboratorial analysis (2004) Braz Oral Res, 18, pp. 168-173Meneghim, M.C., Pereira, A.C., Silva, F.R.B., Prevalência da cárie radicular e condiç-tiao periodontal em uma população idosa institucionalizada de Piracicaba - SP. (2002) Pesqui Odontol Bras, 16, pp. 50-56Fransson, C., Berglundh, T., Lindhe, J., The effect of age on the development of gingivitis. Clinical, microbiological and histological findings (1996) J Clin Periodontal, 23, pp. 379-385Lima FAP, Góes MF, Consani S. Avaliação in vitro da ação abrasiva de escovas dentais. Odonto. 1998;3:23-7Santos, P.H., (2000) Avaliação da porosidade interna e da rugosidade de superfície de resinas compostas para dentes posteriores submetidas à escovação, , Master's thesis, Piracicaba-SP: Piracicaba Dental School/UNICAMP;, 180pMoore, C., Addy, M., Wear of dentin in vitro by toothpaste abrasives and detergents alone and combined (2005) J Clin Periodontol, 32, pp. 1242-1246Joiner, A., Pickles, M.J., Tanner, C., Weader, E., Doyle, P., An in situ model to study the toothpaste abrasion of enamel (2004) J Clin Periodontol, 31, pp. 434-438Figueiredo, M.C., Bello, D., Avaliação comparativa entre a eficácia de uma escova alternativa e uma escova convencional na remoção de placa dent-acaria. (1999) Rev Fac Odontol Univ Passo Fundo, 4, pp. 13-2

Sub-surface Oxygen and Surface Oxide Formation at Ag(111): A Density-functional Theory Investigation

To help provide insight into the remarkable catalytic behavior of the oxygen/silver system for heterogeneous oxidation reactions, purely sub-surface oxygen, and structures involving both on-surface and sub-surface oxygen, as well as oxide-like structures at the Ag(111) surface have been studied for a wide range of coverages and adsorption sites using density-functional theory. Adsorption on the surface in fcc sites is energetically favorable for low coverages, while for higher coverage a thin surface-oxide structure is energetically favorable. This structure has been proposed to correspond to the experimentally observed (4x4) phase. With increasing O concentrations, thicker oxide-like structures resembling compressed Ag2O(111) surfaces are energetically favored. Due to the relatively low thermal stability of these structures, and the very low sticking probability of O2 at Ag(111), their formation and observation may require the use of atomic oxygen (or ozone, O3) and low temperatures. We also investigate diffusion of O into the sub-surface region at low coverage (0.11 ML), and the effect of surface Ag vacancies in the adsorption of atomic oxygen and ozone-like species. The present studies, together with our earlier investigations of on-surface and surface-substitutional adsorption, provide a comprehensive picture of the behavior and chemical nature of the interaction of oxygen and Ag(111), as well as of the initial stages of oxide formation.Comment: 17 pages including 14 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Biomarkers of exposure to new and emerging tobacco delivery products

Accurate and reliable measurements of exposure to tobacco products are essential for identifying and confirming patterns of tobacco product use and for assessing their potential biological effects in both human populations and experimental systems. Due to the introduction of new tobaccoderived products and the development of novel ways to modify and use conventional tobacco products, precise and specific assessments of exposure to tobacco are now more important than ever. Biomarkers that were developed and validated to measure exposure to cigarettes are being evaluated to assess their use for measuring exposure to these new products. Here, we review current methods for measuring exposure to new and emerging tobacco products, such as electronic cigarettes, little cigars, water pipes, and cigarillos. Rigorously validated biomarkers specific to these new products have not yet been identified. Here, we discuss the strengths and limitations of current approaches, including whether they provide reliable exposure estimates for new and emerging products. We provide specific guidance for choosing practical and economical biomarkers for different study designs and experimental conditions. Our goal is to help both new and experienced investigators measure exposure to tobacco products accurately and avoid common experimental errors. With the identification of the capacity gaps in biomarker research on new and emerging tobacco products, we hope to provide researchers, policymakers, and funding agencies with a clear action plan for conducting and promoting research on the patterns of use and health effects of these products

Variation of selected air quality indicators over the city of Beirut, Lebanon: assessment of regional and local emission sources

It is well established that the Mediterranean region experiences high pollution episodes as a result of its closed location and hot-humid long summers. However, few long-term field measurements have been conducted along the Eastern Mediterranean coast in general and in Arab countries, in particular. Hence, a six-month field study of major indicators like CO, SO2, PM10 and O3 were conducted in Beirut, Lebanon. Measurements on an upwind site showed that the monthly average concentrations of CO, SO2 and O3 were lower than the USEPA air quality standards while the monthly average concentrations of PM10 were higher. Diurnal variations showed that vehicle-induced emissions contribute significantly to CO levels while winter heaters constitute the major source of SO2. High diurnal and nocturnal levels of PM10 and O3 are the results of several local and long-range transport phenomen

Torsionssteifigkeit der Ruderschaftlagerung

SIGLETIB: RA 2207(188) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Satisfação e percepção do usuário do SUS sobre o serviço público de saúde Satisfaction and perception of SUS's users about public health care

A avaliação do grau de satisfação dos usuários do sistema de saúde é um importante indicador a ser considerado no planejamento das ações. O objetivo deste estudo foi avaliar o grau de satisfação de usuários dos serviços de saúde pública municipal quanto aos serviços utilizados. Este estudo tipo inquérito foi conduzido em cinco municípios do Estado de São Paulo. A amostra foi selecionada de forma estratificada e aleatória, sendo entrevistados 471 chefes de família ou respectivos cônjuges. Os dados qualitativos foram analisados pelo método de Análise de Conteúdo, e os dados quantitativos foram processados utilizando-se o software estatístico Epi Info. Dentre os usuários dos cinco municípios, 93,0% utilizam o serviço municipal de saúde. Para 72,0%, os serviços de saúde prestados estão resolvendo os problemas e necessidades da população. Com base no acesso ao atendimento, 57,6% da população queixaram-se da presença de filas para o atendimento. Mais da metade (69,5%) afirmou ter confiança na equipe de saúde; no entanto, muitos relatos demonstraram a carência de um atendimento humanizado. Em relação aos serviços de saúde, 61,7% classificaram-os como ótimo ou bom. Conclui-se que a maior parte dos usuários mostrou-se satisfeita com os serviços de saúde municipais, apesar da grande quantidade de queixas quanto ao atendimento, falta de humanização e acolhimento, deficiência de recursos físicos e materiais. A percepção do usuário é de extrema importância ao se dimensionar o reflexo das ações que vem sendo desenvolvidas no setor saúde, e serve como vetor de direcionamento e planejamento do serviço.<br>The assessment of the degree of users' satisfaction with the health system is an important indicator to be considered in planning actions. The aim of this study was to evaluate the degree of satisfaction of users of health services and municipal services to be used. This survey was conducted in five municipalities of São Paulo. The sample was selected at random, stratified, and interviewed 471 heads of households or their spouses. Qualitative data were analyzed using content analysis and quantitative data were processed using the statistical software Epi Info. Among the users of the five municipalities, 93.0% attended the public health care. To 72.0%, health services are solving the problems and needs of the population. Based on access to care, 57.6% of the population complained about the presence of queues for care. More than half (69.5%) said they had confidence in the health team, however, many reports demonstrated the lack of a humanized care. In relation to health services, 61.7% rated them as excellent or good. We conclude that most users are satisfied with the municipal health services, despite the large amount of complaints regarding care, lack of humanization and welcoming, lack of facilities. The user's perception is of utmost importance when scaling the result of actions that have been developed in the health sector, and serves as a vector of direction and planning service