964 resultados para Polpa dentária


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Pós-graduação em Biociências - FCLAS

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The wood of the gender Eucalyptus occupies a prominence place in relation to other cellulose sources, due to its chemical composition, its low cost, abundance and availability. The dissolving pulp obtaining occurs basically starting from three stages: prehydrolysis of the wood following by cooking and finally by the bleaching process. In the dissolving pulp production is necessary a pretreatment stage for the hemicelluloses removal. Among the chemical cooking processes, the Kraft process is the most used for cellulosic pulps production starting from eucalyptus, in the additive presence or not. The anthraquinone uses in the pulping process has as main purposes increasing the delignification rate as well as protecting the pulp regarding the degradation of the polysaccharide chains. The ECF bleaching process consists of the purification of the pulp through bleaching agents, being excepted the elementary chlorine. The dissolving pulp is a pulp of high a-cellulose content and purity destined to the cellulose derivatives production as carboxymethyl cellulose, nitrocellulose and microcrystalline cellulose. The production of a certain product, as well as its final application, is determined by the chemical properties of the pulp. The present work had as purpose producing cellulosic pulp with kappa number around 9 destined to the production of dissolving pulp in way to evaluate the use of the anthraquinone (AQ) in the Kraft process according to the chemical properties of the obtained pulps. It has been still intended developing an effective technology of bleaching for the high purity and quality dissolving pulp production. The prehydrolysis was accomplished in laboratory rotational autoclave for 30 minutes at 170ºC in the water:wood rate 3,5:1 (L:kg). The Kraft/AQ pulping were accomplished in laboratory rotational autoclave being initially modified the active alkali load (10, 13, 16 and 19%) at sulfidity of 25% ...

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The alimentary act of three species of frugivorous bats of the genus Artibeus: A. lituratus, A. fimbriatus and A. planirostris, in a total of nine individuals, was studied by observations in field and captivity, during the months of May to September of 2008. With the objective to caracterize the form of consumption of two tipes of fruits (soft and consistent) and it relates with the dentary structure of this bats, the alimentary act was film and analysed later. It had little variation between the species. The fruits had been consumed in similar way, being that statistics analisis had demonstrated that consistent fruits had received more lateral bytes than the soft fruits. The dentary analisis shown that the posterior teeth (pre-molar and molar) present important characteristcs to triturate pieces of more consistent fruits and the incisors serve to scrape the pulp of the soft fruits. This study it served to describe the form of feeding of frugivorous bats, that little is explained in the studies of alimentary behavior

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The search for a more aware use of available raw materials has led to a need to create more sustainable products. The use of natural fibers to reinforce cement, for instance, has been widely studied in the past decades because of the possibility that they can improve material properties such as thermal resistance and to compression, besides conferring a decrease in their total weight. This present study aimed at to conduct preliminary studies on the thermal resistance of the composite cement - Cellulose Pulp, using waste from the pulp and paper industry. Through experiments, it was found that the composite manufactured using the ratio 30 % Portland cement and 70 % pulp, showed satisfactory results regarding its thermal resistance, so it could be considered as a potential thermal insulation material, for use in constructions

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Objective: this study aimed to analyze the in vitro effect of brushing on the color stability of ceramic brackets immersed in dye solutions. Materials and Methods: seven ceramic brackets of four commercial brands were tested: two monocrystalline and two polycrystalline. The parameters of color were obtained by spectrophotometer before and after 21 days of immersion of the brackets in coffee, red wine, Coca-Cola, black tea and artificial saliva. Another group of brackets of each brand were also immersed in the same solutions and for an equal time to the previous group, but with intervals of daily brushing performed by a toothbrushing machine (Mavtec). The data were evaluated by analysis of variance, multiple comparison tests for means and Student's t-test. Results: the mean color change of the brackets without brushing ranged from 0.46 to 7.61, while in the group with brushing these means ranged from 0.36 to 2.50. The staining still remained noticeable (change of color greater than 3.7) for all brackets when immersed in black tea. Conclusion: daily brushing helped significantly in the color stability of ceramic brackets, maintaining the color change to levels considered not visible to the human eye, except for the solution of black tea in which the staining remained relevant.

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The development of new dental materials has expanded dental therapeutic modalities ensuring excellence in aesthetic restorative treatments. Thus, the direct restorative procedures have been used in cases of dental reconstruction allowing an effective treatment with a low cost, while preserving healthy tooth structure. However, the clinician must be used to the techniques and the material in order to ensure longevity and success in the direct restorative procedure. The aim of this paper is to descrive, after completion of periodontal surgical procedures, the direct restorative step performed for dental reconstruction and diastema closure. The integration between Restorative Dentistry and periodontics enableb the restoration of a harmonious smile in a conservative manner, ensuring aesthetics and patient stisfaction.

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

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The knowledge of risk of carried during pregnant is essential for an appropriate treatment using educational and preventives actions to mother for a good care of their oral health and that of children. The main objective of present retrospective study was to identify the risk of caries of pregnants (aged 15-44, mean= 25 years) came to clinic of Preventive Odontology of Araraquara-UNSEP from 1999 to 2007, using 166 medical records obtained by the third pregraduate year students, following the pre-established guidelines. The information collected includes: classification of caries risk diagnosis, pregnancy trimester, carbohydrates ingestion (between or during foods), dental plaques (O'Leary's plaque control registry) and the number of teeth with caries. The statistical analysis used the Chi2 and ANOVA tests. Most of patients showed a 25 % or more of teeth surfaces with dental plaques (92.1 %) and carbohydrates consumption among foods (89.2 %). The mean (SD) of carried and restores teeth was of 7.9 (5.1) and 4.0 (3.4), respectively and the posterior teeth were the more involved by caries/restorations. As regards the diagnosis of caries risk, classification of high risk was observed in the 38.5 % of pregnants, moderate in the 47.6 %) and low in the 13.9 %. There was a statistically significant association (p= 0.001) between the carbohydrates consumption and the diagnosis of caries risk. The plaque's rate was similar in the different trimesters of pregnancy (f= 0.223; p= 0.803). The caries risk of most pregnant women was high or moderate and it was associated with the consumption of carbohydrates.

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Introduction: Despite tooth avulsion following trauma being relatively common in children, the available studies show that adults have limited knowledge about it. Aim: The purpose of this study was to assess, by a questionnaire, the mothers’ general knowledge about the immediate management of tooth avulsion. Material and method: This descriptive study was carried out on a convenient sample of mothers (n= 65) who participated of the “Pastoral da Criança”, from Araraquara, SP, Brazil. The questionnaire comprised 15 questions about personal data and knowledge on tooth avulsion management. Results: Participants were, on average, 35 years old. A total of 30.8% of the mothers reported that their children suffered dental trauma. The majority had never received advice on this subject (76.9%); and did not know how teeth are kept in the dental arch (69.2%). Almost a half of the sample believed that an avulsed tooth can be replanted (49.2%). In relation to the management of tooth avulsion, 40% of them would clean the avulsed tooth with water, even if it was not dirty (38.5%). Most of them (69.2%) would take the tooth by hand for cleaning purposes, regardless the tooth region; and believed that brushing the tooth was important to take the dirty out (67.7%). Conclusion: The general knowledge of mothers about the immediate management of tooth avulsion was considered inadequate endangering the successful treatment of tooth avulsion.

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Introduction: Upper teeth, especially first premolars and molars, can have a close anatomical relationship with the floor of maxillary sinus. For this reason, accidental displacement of dental roots into the sinus could happen during exodontic procedures. Objective: Description the treatment performed to remove a tooth root within the maxillary sinus, displaced during an extraction procedure. Case Report: Female patient, 39 years of age, which reported being subjected to the extraction of the element 26 for about two months. The patient was reported by the practitioner who performed the extraction that a root was pushed into the maxillary sinus. The treatment plan included surgery to remove the root within the maxillary sinus. Final Comments: Clinicians should be careful during extractions, to prevent these accidents. However, if such complications occur, access to the maxillary sinus is the best treatment option.