Caracterização de superfície, adesiva e mecânica de uma zircônia parcialmente estabilizada por ítria em função da partícula ou do momento do jateamento

Pós-graduação em Reabilitação Oral - FOAR

MTA e hidróxido de cálcio como materiais obturadores de canal radicular em reimplante tardio de dente de macaco

O tratamento endodôntico é uma etapa importante do protocolo de atendimento do reimplante dentário e tem uma relação direta com o aparecimento das reabsorções radiculares, maior causa de perda dos dentes reimplantados. O objetivo do trabalho foi analisar o processo de reparo no reimplante tardio de dente de macaco, utilizando o hidróxido de cálcio (Ca(OH)2) e o MTA como materiais obturadores de canal. Cinco macacos Cebus apella adultos tiveram seus incisivos laterais superiores e inferiores, direito e esquerdo, extraídos e deixados em meio ambiente por 60 minutos. Decorrido esse período, foi realizado o preparo biomecânico dos canais e os dentes foram divididos em dois grupos experimentais: grupo I - canal preenchido com pasta de Ca(OH)2 e grupo II - canal preenchido com MTA (Angelus®). Após o selamento da abertura coronária com ionômero de vidro, o ligamento periodontal foi removido e os dentes imersos em solução de fluoreto de sódio 2%, pH 5,5, por 10 minutos. Em seguida, os alvéolos foram irrigados com soro fisiológico e os dentes reimplantados e contidos por 30 dias com fio de aço e resina composta. A eutanásia dos animais foi realizada 60 dias após o reimplante. Os espécimes de ambos os grupos apresentaram reabsorção por substituição e pontos de anquilose ao longo dos três terços radiculares e ausência de reabsorção inflamatória. Não houve diferença significante entre os dois grupos com relação à reabsorção por substituição, porém a quantidade de anquilose foi significativamente maior no grupo do Ca(OH)2. Baseado nesses resultados conclui-se que o MTA pode ser uma opção clínica viável para a obturação de dentes tardiamente reimplantados que necessitam de um longo período de curativo com hidróxido de cálcio.

Microparticulated and nanoparticulated zirconium oxide added to calcium silicate cement: Evaluation of physicochemical and biological properties

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of colloidal silica on the mechanical properties of fiber-cement reinforced with cellulosic fibers

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

Potential of bamboo organosolv pulp as a reinforcing element in fiber-cement materials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pre-extrusion aromatization of a soy protein isolate using volatile compounds and flavor enhancers: Effects on physical characteristics, volatile retention and sensory characteristics of extrudates

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biocompatibility of New Calcium Aluminate Cement: Tissue Reaction and Expression of Inflammatory Mediators and Cytokines

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

Effect of surface treatment on the bond strength between yttria partially stabilized zirconia ceramics and resin cement

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of tensile tetention of Y-TZP crowns after long-term aging: Effect of the core substrate and crown surface conditioning

This study evaluated the effect of the core substrate type (dentin and composite resin) on the retention of crowns made of yttrium oxide stabilized tetragonal zirconia polycrystal (Y-TZP), submitted to three inner surface conditionings. For this purpose, 72 freshly extracted molars were embedded in acrylic resin, perpendicular to the long axis, and prepared for full crowns: 36 specimens had crown preparations in dentin; the remaining 36 teeth had the crowns removed, and crown preparations were reconstructed with composite resin plus fiber posts with dimensions identical to the prepared dentin. The preparations were impressed using addition silicone, and 72 Y-TZP copings for the tensile test were produced. Cementation was performed with a dual-cured cement containing phosphate monomers. For cementation, the crown preparation (dentin or resin) was conditioned with the adhesive system, and the ceramic was subjected to one of three surface treatments: isopropyl alcohol, tribochemical silica coating, or thin low-fusing glassy porcelain layer application plus silanization. After 24 hours, all specimens were submitted to thermocycling (6000 cycles) and placed in a special tensile testing device in a universal testing machine to determine failure loads. The failure modes of all samples were analyzed under a stereomicroscope. Two-way analysis of variance showed that the surface treatment and substrate type (alpha=0.05) affected the tensile retention results. The dentin substrate presented the highest tensile retention values, regardless of the surface treatment. When the substrate was resin, the tribochemical silica coating and low-fusing glaze application plus silanization groups showed the higher retention values.

Radiopacity, pH and antimicrobial activity of Portland cement associated with micro- and nanoparticles of zirconium oxide and niobium oxide

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

Iliac osteosynthesis with nylon clamp associated to polymethylmethacrylate bone cement - experimental study in dogs cadavers

Fractures of iliac body are generally consequences of traumas of great impact. These fractures lead to a lack of locomotor response and in specific cases, surgery is needed. Among the possible therapeutic lines, implants become a good option. In this paper, the authors used dog corpses to develop a surgery technique of iliac osteosynthesis, employing nylon clamps and bone cement of polymethylmethacrylate (PMMA). Sixteen hemi pelvises of eight dog corpses, which had its iliac bodies totally fractured previously, were utilized. The osteosynthesis was reached through the implantation of six nylon clamps, distributed equally between the bone fragments. With the use of the nylon clamps there were bone realignment and a contact surface to fixation of the biomaterial. The technique developed in corpses was easily executed, effective in reduction, alignment and stabilization of the fracture. The authors suggest more studies in vitro to evaluate immobilization resistance and functionality in dogs with this condition.

Caracterização de uma cerâmica 3Y-TZP e avaliação do efeito de tratamentos de superfície na adesão da cerâmica ao glaze ou cimento resinoso

Pós-graduação em Odontologia Restauradora - ICT

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.

Incorporation of chlorhexidine gluconate or diacetate into a glass-ionomer cement: porosity, surface roughness, and anti-biofilm activity

To evaluate the porosity, surface roughness and anti-biofilm activity of a glass-ionomer cement (GIC) after incorporation of different concentrations of chlorhexidine (CHX) gluconate or diacetate. Methods: For the porosity and surface roughness tests, 10 test specimens were fabricated of the GIC Ketac Molar Easy Mix (KM) and divided into the following groups: Control, GIC and 0.5% CHX diacetate; GIC and 1.0% CHX diacetate; GIC and 2.0% CHX diacetate; GIC and 0.5% CHX gluconate; GIC and 1.0% CHX gluconate; GIC and 2.0% CHX gluconate. To evaluate porosity, the test specimens were fractured. The fragments were photographed by scanning electron microscopy (SEM), and the images analyzed with the aid of the software program Image J. The surface roughness (Ra) was obtained by the mean value of three readouts performed on the surface of each specimen, always through the center. To analyze the anti-biofilm activity, strains of S. mutans ATCC 35688 were used, and the groups control and GIC +CHX diacetate 1% were divided as follows: GIC (1 day); GIC (7 days), GIC (14 days), GIC (21 days); GIC+CHX (1 day), GIC+CHX (7 days), GIC+CHX (14 days), GIC+CHX (21 days); GIC+ CHX (1 day), GIC+ CHX (7 days), GIC+ CHX (14 days) and GIC+ CHX (21 days) using 10 test specimens per group. For biofilm growth, the specimens were placed in a vertical position in 24-well plates and incubated overnight 10 times. The culture medium was renewed every 24 hours. The suspension was diluted and seeded on BHI agar for quantification of the bacteria present. For evaluation of all the tests the two-way ANOVA was used, and if necessary, the Tukey test was applied, with a level of significance of 5%. Results: Regarding GIC porosity, the ANOVA showed that the presence of CHX increased the porosity (P< 0.001) proportionally to the increase in concentrations (P= 0.001), without however, presenting interaction between material and concentration (P= 0.705). Regarding the number of pores, a significant increase in pores was observed with the increase in CHX concentration (P= 0.003). The surface roughness test demonstrated no statistically significant effect as to increase or reduction in roughness at any of the CHX concentrations used (P> 0.05). Anti-biofilm activity analysis pointed out a significant effect of the factors material (P= 0.006) and time (P< 0.001), with CHX diacetate CHX presenting greater effectiveness in reducing microorganisms.