Resistência de união ao microcisalhamento de sistemas adesivos autocondicionates com graus de acidez distintos: efeito de diferentes tratamentos em substrato dentinário normal e hipermineralizado artificialmente

Pós-graduação em Ciências Odontológicas - FOAR

Estudo comparativo entre dois adesivos no desempenho mastigatório de usuários de próteses totais

Pós-graduação em Reabilitação Oral - FOAR

Avaliação da microinfiltração marginal em restaurações de classe V em resina composta em dentes bovinos: efeito de diferentes equipamentos para preparos cavitários e sistemas adesivos

Pós-graduação em Odontologia Restauradora - ICT

Estudo das características térmicas e mecânicas de formulações de adesivos PSA HOT MELT contendo variações de borrachas SBC e resinas taquificantes

The properties of the hot melt adhesive pressure sensitive (HMPSA) using an elastomer as a base polymer a copolymer of styrene and butadiene (SBS) and variation of tackifiers resins such as hydrocarbon resins and hydrogenated hydrocarbon were investigated. The formulations were prepared by mixing process within shear. The adhesives prepared were evaluated in test Brookfield viscosity and softening point Ring and Ball to compare the formulations and the influence of variations in raw materials. Infrared analyzes were performed to detect the reactions between the inputs and investigate the chemical interactions of the same properties of the adhesive. In thermal analysis, the assay was performed thermogravimetry (TG) and diferencial exploratory calorimetry (DSC). Were investigated the parameters of the tensile test on each of the formulations. Finally, were analysed comparatively the basic formulations of adhesives with their respective raw materials

Caracterização física e mecânica de compensado produzido com dois diferentes adesivos em duas variações de pressão de prensagem

The adhesives used in the production of engineered boards have been object of study over the years in order to improve the properties of the boards with less energy consumption, lower production costs and reduced environmental impact. In addition to that, process variables may affect the properties of the board. The present study aimed to characterize sheets of plywood, manufactured with two types of adhesives, under two different pressing conditions. The adhesives used for the study were Phenol-formaldehyde and Polyurethane castor oil based. The pressure of pressing was varied in a range from 75 to 160 Bar, in order to verify how they influence the physical and mechanical properties of the board. The tests performed resulted in a conclusion that shows that the moister content of the veneers interferes on the physical and mechanical tests. In general, boards produced with polyurethane resin showed superior physical and mechanical results; although the ones produced with phenol formaldehyde at a pressure of 75 Bar had always equal or higher values, compared to what is found in literature

Análise do desempenho físico-mecânico de painéis compensados de Pinus sp. produzidos com adesivos aquosos a base de poliacetato de vinila e de homopolímero vinílico

This study aimed to evaluate the physico-mechanical performance of three PVA adhesive formulations according to the Brazilian standards for plywood testing and to evaluate the results with those presented in the technical literature and specified in normative documents. The study presents the production process of the panels, the obtaining of samples and, finally, the implementation of physico-mechanical characterization tests based on plywood Brazilian standards. For the panels production it was used a gramature of 120 g / m² and applied a pressure of 15 bars and two temperature combinations and pressing time for each adhesive. The commercial adhesives used were PVA 1810, PVA 1060 and Vinyltec 239. The physical tests conducted were thickness swelling, density, moisture content and water absorption. The mechanical tests were static flexion, for the determination of elasticity modulus (MOE) and rupture modulus (MOR), and shear in the glue line. Among the three formulations studied none showed good performance in the presence of water. However, other trials in the adhesive showed better results and closer to the commercially equivalent used, in the case the urea-formaldehyde, was the PVA 1810, that can be applied in non-structural uses and in environments without the presence of moisture

Aplicação de adesivos estruturais em painéis de carros

The automobile industry is increasingly interested in reducing vehicle weight for greater speed, lower fuel consumption and emissions, through innovation of materials and processes. One way to do this is to seek the replacement of conventional processes by the use of structural adhesives. Structural adhesives are highly resistant materials, which can replace rivets, bolts and welds allowing the substrate / adhesive assemble is stronger than the substrate itself. One of the major advantages of gluing with respect to welding is its esthetic appearance, since it does not leave marks. For this reason, parts to be soldered require a minimum thickness so that the marks do not appear, since the pieces from gluing have no restriction as to the thickness. By replacing the vibration welding process for gluing process of the instrument panel parts of an automobile, one obtains a reduction of the thickness of the parts and therefore it decreases the weight of the car. This work aims to study the various structural adhesives that already exist on the market to be applied on the instrument panel. The mechanical test performed to measure the maximum adhesive strength was the Lap Shear Test at 23°C (room temperature), -35°C and 85°C. The types of adhesives used were the hot-melt and the bi-component. By the results obtained, it is in favor using the bi-component for application to the union of instrument panel parts

Variáveis que afetam o procedimento de colagem direta ortodôntica: braquetes e materiais adesivos

Following the introduction of the acid-etching technique in enamel surface, direct attachment of orthodontic appliances on the surface of the tooth and/or restorations became a routine procedure in the assembly of the fixed devices. The attainment of a success result is related to the criterion attention to the details and the steps of the bonding technique, as well as, to the knowledge of the characteristics of the adhesive materials and orthodontic brackets. This paper presents some aspects of various types of brackets and adhesives materials.

Efeitos da aplicação de resina hidrofóbica sobre a resistência de união de adesivos autocondicionantes de frasco único

Introduction: It is known that self-etching adhesive systems can act as semi-permeable membranes. Objective: Evaluate the effects of additional layer of hydrophobic resin on the microtensile bond strength of self-etching one-bottle adhesives. Material and method: Sixty bovine incisors were used in this study. The facial enamel surfaces of the crowns were abraded with silicon carbide paper to expose flat, mid-coronal dentin surfaces. The following adhesives were used: Clearfil Tri S Bond (CTSB), AdheSE One (ADH) and One Coat  7.0 (OC). Each material was tested with and without applying an additional layer of hydrophobic material from the same manufacturer. Z-350 composite resin was inserted in three 1 mm increments. All adhesive restorative procedure was performed under simulated pulpal pressure and the microtensile test was performed immediately after curing the composite resin. Data were submitted to ANOVA and Tukey test (p < 0.05). Result: For all adhesives tested, the worst results were observed in groups which the additional layer of hydrophobic resin was not applied. Conclusion: The application of additional layer of hydrophobic material can improve the adhesion of self-etching all-in-one adhesive systems.

Influência da dentina bovina e do dispositivo de microtração na resistência de união de sistemas adesivos

Pós-graduação em Odontologia Restauradora - ICT

Emprego de ma teriais rest auradores adesivos direto no ângulo incisal de incisivos centrais fra turados

A case report of a patient who presents as chief complaint presence of stained restorations in the anterior teeth. After analysis and discussion of the clinical therapeutic approaches to be adopted, it was observed the presence of type class IV restorations on teeth 11 and 21, due to an oblique coronal fracture in the past. But the patient was not satisfied with the aesthetic result, then where was planned the realization of the removal of the restorations, for subsequently be used direct restorative materials for the correction of form, function and esthetics. The final result showed that the restorations were able to return the form, function and aesthetic dental, thereby evidencing the proven development of restorative dentistry in the solution of aesthetic problems.

Emprego de técnica cirúrgica e materiais adesivos diretos no fechamento de diastema

The following is a clinical case report of a patient whose main complaint was the presence of a generalized spacing in the anterior maxillary segment. After meticulous clinical analysis and discussions of the clinical procedures to be adopted, a labial frenectomy was our first choice, so that we could reduce the diastemas directly using composite resin. It was observed that the association of clinical and restorative procedures was capable of giving back shape, function and dental aesthetics, allowing to the young patient the satisfaction of smiling without any fear.

Prevalencia de defectos óseos en elementos dentarios con anquilosis o reabsorción por reemplazo extraídos tempranamente

En la mayoría de los casos de dientes anquilosados la opción de tratamiento aceptado ha sido la remoción quirúrgica, la cual es frecuentemente acompañada por la rotura traumática del hueso alveolar, particularmente en los casos de la presencia de una delgada tabla vestibular del maxilar. Como en la mayoría de los casos de trauma dental y reimplantación dentaria con la subsiguiente anquilosis se involucran zonas anteriores del maxilar, tales extracciones traumáticas de los dientes anquilosados pueden llevar a deformaciones estéticas de la cresta osea, las que podrían interferir en un óptimo tratamiento protético.

Resistências adesivas de diferentes sistemas adesivos ao MTA e Biodentine™

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz