Estudo, desenvolvimento e concepção de uma célula de carga

In engineering projects, it’s fundamental to determine the active loads in components in order to guarantee acceptable values of safety and reliability according to project specifications. On the other hand, force measurement methods might be very complex and impracticable in some cases and, so that, load cells with eletric resistance strain gages can be applied as a simple and accurate option to measure the required load. The main purpose of this paper is to present the development of a load cell that measures uniaxial forces using electric resistance strain gages without being influenced by the location of the loading in a cantilever beam. For that, it was taken as basis a secondary purpose which is to present a general study of basic and wide concepts about transducers, load cells and extensometers primarily. Information such as: loading and measurements types, characteristics of the presented devices as well as factors that influence its functioning, the most common kinds of Wheatstone bridge links, the main points of a load cell project, cements used to fix extensometers and, finally, the project itself with the tests of the built transducer are presented. By the end of this paper, all the results are shown and analyzed, concluding about the designed load cell and the work itself

Confecção e avaliação de chapas de madeira aglomerada com aproveitamento de resíduos de marcenaria industrial

Pós-graduação em Engenharia Civil - FEIS

Efeito do tipo de adesivo e do seu mecanismo de ativação, assim como da viscosidade da resina composta, na resistência de união à dentina antes e após envelhecimento artificial

Pós-graduação em Odontologia Restauradora - ICT

Subjective assessment of adhesives usage by complete denture wearers in a brazilian population

The information about the knowledge and usage of denture adhesives is still limited, particularly in Brazilian populations. Objective: The purpose of this study was to investigate the aspects related to the use or nonuse of denture adhesives by complete denture wearers. Material and method: Questionnaires were applied to 100 bimaxillary complete denture wearers concerning their usage of denture adhesives. The survey was carried out according to three categories: those who had never tried adhesive, those who had tried adhesive at least once but no longer used it, and those who currently used it. Result: Of the 100 participants, 80% had never tried adhesives, 16% had tried at least once but no longer used it and 4% had used on a regular basis. Conclusion: Within the limitations of this study, the results of this subjective assessment suggest that within the participants that had never tried adhesives, 77.5% inform that the adhesive is not needed, and all participants who regularly use it inform its efficiency.

Clareamento para dentes despolpados: revisão de literatura e considerações

The esthetics of the teeth is not a privilege of our days, because concerns in that effect have been reported since 1860. Faced with an endodontically treated tooth that presents any type of color change, professionals can use intracoronary bleaching, which is more conservative attempt to restore the normal color of teeth. Bleaching aims to remove pigments by oxidizing agents and for that, various techniques were developed. Among the risks of tooth whitening the external resorption is the most severe, which occurs when the whitening penetrates through the dentin tubules to the periodontal ligament and initiates an inflammatory response. To prevent external resorption is required to place an intracoronal bleaching barrier. It is important to know the time between the bleaching treatment for restoring procedure for getting a good sealing to prevent microleakage. This study aims to review the literature about the different types of bleaching agents and their risks.

Marginal adaptation of Class V restorations with current generation dentin-bonding agents: effect of different dentin surface treatments.

This study sought to assess the use of chlorhexidine with several excipients as a dentin surface treatment and its effect on marginal adaptation of class V restorations with current-generation dentin bonding agents. A total of 120 human third molars were selected and allocated into 12 groups, with standardized buccal class V restorations randomly divided into preconditioned dentin rinsed with: water; water + chlorhexidine; ethanol; or ethanol + chlorhexidine. After rinsing of dentin (previously conditioned with 35% phosphoric acid) with the test solutions, the Adper single bond 2, prime and bond 2.1, and Excite bonding systems were applied randomly. Restorations were performed with FiltekTM Z350 XT composite resin. The resulting specimens were subjected to thermal and mechanical load cycling. Quantitative analysis of marginal adaptation was performed on epoxy replicas by means of scanning electron microscopy. Results were assessed by means of the Kruskal-Wallis test (percentages of continuous margins) and Wilcoxon test (differences between percentages of continuous margins before and after thermal cycling and mechanical loading), at a significance level of p < 0.05. Outcomes in the chlorhexidine-treated groups were not superior to those obtained with other treatments.

Reparo de uma restauração classe IV com o uso de resina composta nanoparticulada: quatro anos de acompanhamento

O aprimoramento da odontologia estética restauradora está ligado ao desenvolvimento de materiais e técnicas inovadoras, os quais podem oferecer diversos benefícios, incluindo a integração cromática, policromatismo, forma anatômica, função, adequado contato proximal e aumento da integridade marginal. Em função desses aspectos, as restaurações de resina composta, aplicadas de forma direta, tendem a ganhar maior longevidade. Assim, o objetivo do presente relato de caso é fornecer ao leitor a visão dos desafios restauradores envolvidos no reparo de uma fratura classe IV de um dente incisivo superior, utilizando-se um novo sistema de resina composta híbrida nanoparticulada (FiltekTM Supreme - 3M ESPE). Resultados: com base no referido material e técnica, otimizamos a obtenção de resultados satisfatórios alcançados por meio da utilização adequada do sistema adesivo e resina composta, mantidos com sucesso após o acompanhamento de 4 anos. Conclusão: pode-se concluir que, interagindo técnica adequada de aplicação, princípios adesivos básicos e materiais de qualidade, o clínico pode garantir o sucesso na restauração da forma, função e estética de dentes anteriores.

Adesão de células sanguineas em raízes biomodificadas de pacientes fumantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação do uso de Selante de Fibrina derivado do veneno de serpente como arcabouço biológico de células tronco mesenquimais na regeneração óssea do fêmur de ratos

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

Descontaminação do resíduo industrial de couro, uma proposta para o desenvolvimento sustentável nos curtumes

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Abordagens estatísticas em testes de resistência de união entre dentina bovina, sistema adesivo e resina composta

Pós-graduação em Odontologia Restauradora - ICT

Diffusion of hydroxyl ions from calcium hydroxide and Aloe vera pastes

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

Avaliação da capacidade seladora apical de um adesivo dentinário, acrescido ou não de hidróxido de cálcio, comparada à de um cimento endodôntico à base de hidróxido de cálcio, na obturação de canais radiculares

Pós-graduação em Odontologia Restauradora - ICT

Pré tratamento dentinário influência do condicionamento ácido, irradiação laser e hipermineralização na resistência ao cisalhamento de sistema adesivo multi uso

The disadvantages generated by the acid etching of the dentin, such as an increase in its permeability, in the surface moisture and in the potential to denature the external dentinal collagen, the formation of a fragility zone and the citotoxicity of the adhesive monomers; which are all aggravated by the depth of the dentin, have stimulated new and different treatment philosophies of the dentin. The purpose of the present study, therefore, was to investigate the effects of three dentin treatments: laser irradiation, acid etching and hypermineralization, in the shear bond strength of the SMP Plus bonding system. Sixty bovine incisors were extracted and randomly selected immediatly alter the animal's death. They were kept frozen (-18°C) for no longer than 14 days. After buccal dentinal surface had been exposed, X-Rays were taken to control the dentin thickness. The specimens were separated into two groups: (1) Control, kept in distilled water at 4ºC; (2) Mineralized, kept in hypermineralized solution at 4°C for 14 days. Each group was divided into three sub-groups according to the type of dentin treatment used: group F - followed the manufacturer instructions (acid-etching + primer + bond), group AL (acid-etching + primer + bond + laser) and group LA (laser + (laser + acid-etching + primer + bond). A composite resin standard cylinder (Z100-3M) was bond to the dentinal surface and the shear bond strength performed on a Universal lnstron machine 4301, with 500 Kg load and at 0,5mm/min. speed. The analysis of variance (ANOVA) determined that the treatments influenced the shear bond strength values (p<0,05) with the following average shearing load at failure: AL (9,96 MPa), F (7,28MPa) e LA (4,87 MPa). The interaction between the two factors analyzed Group (control and mineralized) and treatment (F, AL, LA) also influenced the shear bond strength (p<0,05). The highest values were obtained...

Impacto do uso de fita adesiva na qualidade de vida de pacientes institucionalizados e usuários de próteses totais convencionais

Objective: Evaluate the impact of the use of strip adhesive over the quality of life of institutionalized patients and wearers of complete dentures. Material and method: Twenty-nine institutionalized patients wearers of complete denture were selected to this study and after a clinical exam, a questionnaire (adjusted and based upon the index of Oral Health Impact Profile and Oral Health-Related Quality of Life, OHIP and OHQOL) was applied to evaluate issues related to epidemiological conditions (gender and age), quality of life (pain, discomfort, functional limitations, phonetic, social, psychological and esthetic), taste and notion of implant treatment. Following this part, the patients received instruction to use the strips adhesives (Corega Fita Adesiva, Glaxo-Smith-Kline, Rio de Janeiro, Brazil), considering three in maxillary prosthesis and two in the lower prosthesis during a period of 30 days. After this period, all the patients were recall and the questionnaire was reapplied; add some adhesive performance questions, to compare the results before and after the adhesive use in terms of percentage. Result: After the adhesive strips use there were improvement of the functional, social and physcological limitation aspects, but without percentual increasement of phonetic and esthetics aspects. The results showed 65.5% of the answers stating adhesive maintenance between 6-12 hours, easy removal (68.9%), and without change the taste (89.6%). The notion for implant treatment was decreased changing from 75.8 to 37.9% after the adhesive use. Conclusion: The results enhanced a positive impact over quality of life of the respondents after the strip adhesive use, showing decrease of pain and discomfort, mainly of inferior dental prosthesis.