Caracterização de compositos de matrizes poliméricas reforçadas com fibra de sisal e de vidro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação em modelo fotoelástico do sistema de força gerado pela mola T de retração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de tratamento de superfície do titânio comercialmente puro na resistência de união com cimentos ionomérico e resinosos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de tratamento de superfície na composição de zircônia e na resistência de união com diferentes cimentos

Pós-graduação em Reabilitação Oral - FOAR

Adesão de um cimento resinoso a uma cerâmica feldspática: avaliação da resistência adesiva, ângulo de contato e ph, em função de diferentes técnicas de condicionamento

Pós-graduação em Odontologia Restauradora - ICT

Avaliação do selamento marginal em restaurações de resina composta executadas em dentes bovinos, variando os métodos de preparos cavitários e os meios de fotopolimerização

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento e avaliação da efetividade de duas pastas polidoras em padrão nanométrico empregadas a materiais restauradores estéticos: análise comparativa por perfilometria digital e microscopia de força atômica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da clorexidina e laser sobre a adaptação externa de resina a base de silorano em cavidade hígida e afetada por cárie

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da resistência de união ao cisalhamento, de diferentes sistemas adesivos à dentina. Análise em MEV do infiltrado resinoso

Pós-graduação em Ciências Odontológicas - FOAR

Some Physical and Mechanical Properties of Medium-Density Fiberboard Made from Giant Bamboo

The objective of this study was to evaluate the density, density profile, water swelling and absorption, modulus of elasticity and rupture from static bending, and tensile strength of experimental medium-density fiberboards manufactured using Dendrocalamus giganteus (Munro bamboo). The fiber production was carried out through the chemo-thermo-mechanical pulping process with four different conditions. The panels were made with 10% urea formaldehyde resin based on dry weight of the fibers, 2.5% of a catalyzer (ammonium sulfate) and 2% paraffin. The results indicate that treatments with the highest alkali (NaOH) percentage, time and splinter heating temperature improved the physical properties of the panels. The root-fiber interface was evaluated through scanning electron microscopy in fracture zones, which revealed fibers with thick, inflexible walls. The panels' mechanical properties were affected due to the fiber wall characteristics and interaction with resin. Giant bamboo fiber has potential for MDF production, but other studies should be carried out.

Characterization of a polymer-infiltrated ceramic-network material

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Primate Pulpal Healing after Exposure and TheraCal Application

Aim: The purpose of this in vivo study was to compare the effectiveness of a new light cured resin based dicalcium/tricalcium silicate pulp capping material (TheraCal LC, Bisco), pure Portland cement, resin based calcium hydroxide or glass ionomer in the healing of bacterially contaminated primate pulps. Study design: The experiment required four primates each having 12 teeth prepared with buccal penetrations into the pulpal tissues with an exposure of approximately 1.0 mm. The exposed pulps of the primate teeth were covered with cotton pellets soaked in a bacterial mixture consisting of microorganisms normally found in human pulpal abscesses. After removal of the pellet, hemostasis was obtained and the pulp capping agents applied. The light cured resin based pulp capping material (TheraCal LC) was applied to the pulpal tissue of twelve teeth with a needle tip syringe and light cured for 15 seconds. Pure Portland cement mixed with a 2% Chlorhexidine solution was placed on the exposed pulpal tissues of another twelve teeth. Twelve additional teeth had a base of GIC applied (Triage, Fuji VII GC America) and another twelve had a pulp cap with VLC DYCAL (Dentsply), a light cured calcium hydroxide resin based material. The pulp capping bases were then covered with a RMGI (Fuji II LC GC America). The tissue samples were collected at 4 weeks. The samples were deminerilized, sectioned, stained and histologically graded. Results: There were no statistically significant differences between the groups in regard to pulpal inflammation (H= 0.679, P=1.00). However, both the Portland cement and light cured TheraCal LC groups had significantly more frequent hard tissue bridge formation at 28 days than the GIC and VLC Dycal groups (H= 11.989, P=0.009). The measured thickness of the hard tissue bridges with the pure Portland and light cured TheraCal LC groups were statistically greater than that of the other two groups (H= 15.849, P=0.002). In addition, the occurrence of pulpal necrosis was greater with the GIC group than the others. Four premolars, one each treated according to the protocols were analyzed with a microCT machine. The premolar treated with the light cured TheraCal LC demonstrated a complete hard tissue bridge. The premolar treated with the GIC did not show a complete hard tissue bridge while the premolar treated with VLC Dycal had an incomplete bridge. The pure Portland with Chlorhexidine mixture created extensive hard tissue bridging.Conclusion: TheraCal LC applied to primate pulps created dentin bridges and mild inflammation acceptable for pulp capping.

Aproveitamento de resíduos de laminação da madeira para a produção de painel estrutural

Products derived from wood or engineered products are becoming interesting alternatives to the replacement of solid wood in various applications, from structural components to the furniture industry and packaging. Among these products, there are panels built by strands, particles and fibers, each one having their particular characteristics and potential of use. Since the different types of panels are produced, waste generation is part of the process, and that more technological it is, it still generates losses of raw materials. Based on the need for rational use of raw materials and using almost full of industrially processed wood, It arises the proposal of this work, which seeks to use waste from the lamination, like pieces of strands, broken strands, strands rough, cracked strands to produce panels with structural characteristics of the OSL panel (Oriented Strand Lumber), LSL (Laminated Strand Lumber) and OSB (Oriented Strand Lumber). Besides the use of waste, this paper seeks an alternative to the use of the adhesive, because the industry uses formaldehyde-based adhesives, which over the press, they emit large amounts of formaldehyde, which is very aggressive to humans and environment. The panels made with polyurethane resin based on castor oil and hot-pressed were characterized by physical and mechanical tests according to specifications of European Standard (EN). High values of tensile strength, elastic modulus and density were found in the results of tests. Adding to stable values of swelling and moisture content, the panel studied adds attractive features to the panel market, especially in the civil construction

Desgaste e rugosidade superficial de um cimento de ionômero de vidro nanoparticulado

To compare the abrasion wear resistance and superficial roughness of different glass ionomer cements used as restorative materials, focusing on a new nanoparticulate material. Material and Method: Three glass ionomer cements were evaluated: Ketac Molar, Ketac N100 and Vitremer (3M ESPE, St. Paul, MN, USA), as well as the Filtek Z350 (3M ESPE, St. Paul, MN, USA). For each material were fabricated circular specimens (n=12), respecting the handling mode specified by the manufacturer, which were polished with sandpaper disks of decreasing grit. The wear was determined by the amount of mass (M) lost after brushing (10,000 cycles) and the roughness (Ra) using a surface roughness tester. The difference between the Minitial and Mfinal (ΔM) as well as beroughness of aesthetic restorative materials: an in vitro comparison. SADJ. 2001; 56(7): 316-20. 11. Yip HK, Peng D, Smales RJ. Effects of APF gel on the physical structure of compomers and glass ionomer cements. Oper. Dent. 2001; 26(3): 231-8. 12. Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on the surface characteristics and color of denture resins. J Prosthet Dent 1997; 77(2): 197-204. 13. International organization for standardization. Technical specification 14569-1. Dental Materials – guidance on testing of wear resistance – PART I: wear by tooth brushing. Switzerland: ISO; 1999. 14. Bollen CML, Lambrechts P, Quirynen M. Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater.1997; 13(4): 258-9. 15. Kielbassa AM, Gillmann C, Zantner H, Meyer-Lueckel H, Hellwig E, Schulte-Mönting J. Profilometric and microradiographic studies on the effects of toothpaste and acidic gel abrasivity on sound and demineralized bovine dental enamel. Caries Res. 2005; 39(5): 380-6. 16. Tanoue N, Matsumara H, Atsuta M. Wear and surface roughness of current prosthetic composites after toothbrush/dentifrice abrasion. J Prosthet Dent. 2000; 84(1): 93-7. 17. Heath JR, Wilson HJ. Abrasion of restorative materials by toothpaste. J Oral Rehabil. 1976; 3(2): 121-38. 18. Frazier KB, Rueggeberg FA, Mettenburg DJ. Comparasion of wearresistance of class V restorative materials. J Esthet Dent. 1998; 10(6): 309-14. 19. Momoi Y, Hirosakil K, Kohmol A, McCabe JF. In vitro toothebrushdentifrrice abrasion of resin-modified glass ionomers. Dent Mater. 1997; 13(2): 82-8. 20. Turssi CP, Magalhães CS, Serra MC, Rodrigues Jr.AL. Surface roughness assessment of resin-based materials during brushing preceded by pHcycling simulations. Oper Dent. 2001; 26(6): 576-84. 21. Wang L, Cefaly DF, Dos Santos JL, Dos Santos JR, Lauris JR, Mondelli RF, et al. In vitro interactions between lactic acid solution and art glassionomer cements. J Appl Oral Sci. 2009; 17(4): 274-9. 22. Carvalho FG, Fucio SB, Paula AB, Correr GM, Sinhoreti MA, PuppinRontani RM. Child toothbrush abrasion effect on ionomeric materials. J Dent Child (Chic). 2008; 75(2): 112-6. 23. Coutinho E, Cardoso MV, De Munck J, Neves AA, Van Landuyt KL, Poitevin A, et al. Bonding effectiveness and interfacial characterization of a nano-filled resin-modified glass-ionomer. Dent Mater. 2009; 25(11): 1347-57. tween Rainitial and Rafinal (ΔRa) were also used for statistical analysis (α=0.05). Results: Except for the composite, significant loss of mass was observed for all glass ionomer cements and the ΔM was comparable for all of them. Significant increase in roughness was observed only for Vitremer and Ketac N100. At the end of the brushing cycle, just Vitremer presented surface roughness greater than the composite resin. Conclusion: All glass ionomer cements showed significant weight loss after 10,000 cycles of brushing. However, only Vitremer showed an increase of roughness greater than the Z350 resin, while the nanoparticulate cement Ketac N100 showed a smooth surface comparable to the composite.

Matriz oclusal para restauração com resina composta de baixa contração: simplificação eficiência

The composite resin is the material of election for direct restorations in posterior teeth currently. The restorative dentistry aims to improve each day the material and facilitate the restorative technique. This paper describes the technique of occlusal matrix made to speed up and preservation the occlusal surface of a first molar tooth affected by caries lesion. A new resin-based composite was used called Silorane, which may be placed in larger increments due the material has low shrinkage and polymerization stress. The use of occlusal matrix associated with a low shrinkage resin composite can simplify the clinical work, and result in a restoration with excellent reproduction of anatomical.