Reciclagem de cavacos para a formação de carbonetos de titânio no metal de solda produzido por soldagem GTAW em aço-carbono

Pós-graduação em Engenharia Mecânica - FEIS

Avaliação de métodos de fixação de fraturas distais de rádio e ulna em cães de pequeno porte: revisão sistemática

As fraturas de rádio e ulna em animais de companhia são ocorrências ortopédicas de grande incidência em Medicina Veterinária. Cães de pequeno porte parecem ter uma maior incidência de fraturas em terço distal do rádio e ulna. A consolidação de ossos fraturados baseia-se na redução anatômica ou na aproximação dos maiores fragmentos. Para haver uma correta cicatrização óssea, os implantes ortopédicos devem anular todas as forças atuantes no foco de fratura. O tratamento dessas fraturas é descrito como difícil, em porte do tipo toy e miniatura. A ocorrência da não consolidação óssea é alta chegando a 60% dos casos estudados. Alguns fatores identificados afetam a osteossíntese em cães de raças de pequeno porte, pois são inerentes à instabilidade biomecânica, como, o mínimo contato da superfície do osso após a redução, devido ao pequeno diâmetro existente, diminuição da cobertura de tecido mole, formação constante de cartilagem no foco da fratura, e diminuição da densidade vascular na junção diáfise-metafisária distal em comparação com cães de raças de grande porte. O objetivo da presente revisão sistemática foi avaliar o melhor método de tratamento para fraturas distais de rádio e/ou ulna em cães de raças de pequeno porte. Como metodologia foram utilizados 14 artigos científicos, sendo 11 internacionais e quatro nacionais. A aplicação de placas, nesse estudo sistemático, foi considerado o método mais eficaz para fixação de fraturas distais de rádio e ulna em cães de pequeno porte

Effect of mechanical cycling on screw torque in external hexagon implants with and without platform switching

This in vitro study evaluated the effect of mechanical cycling on the torque of retaining screw in external hexagon implants with platform switching (PS), regular platform (RP) and wide platform (WP). A total of 30 specimens were equally divided into 3 groups: PS, PR and WP. Each specimen was prepared with implants: 3.75 x 10 mm for RP group and 5.0x10 mm for PS and WP groups and its respective abutment with 32 Ncm torque. All groups were subjected to 106 cycles with 100 N (corresponding to about 40 months of chewing). The results were obtained with the reverse torque of each specimen and data were evaluated using ANOVA and Tukey test (p<0.05). The PS group showed statistically significant difference in screw removal torque (30.06±5.42) compared with RP (23.75±2.76) and WP (21.32±3.53) (p<0.05) groups; the RP and WP groups showed no statistically significant difference between them. It was concluded that the PS group showed higher reverse torque value, suggesting lower susceptibility of the abutment screw loosening.

Double-setting alpha-tricalcium phosphate cement provided with interconection channels in rabbits after enucleation: a potential implant for the anophthalmic socket

The purpose of this study was to evaluate the macroscopy and microstructure of a double setting alpha-tricalcium phosphate bone cement sphere provided with interconnection channels (alpha-TCP-i), as well as the integration of the implant with the rabbits' orbital tissue, through macroscopic analysis and histopathology. The external and internal surfaces of the alpha-TCP-i were evaluated macroscopically and by electron microscopy. Twelve New Zealand rabbits received 12mm implants of alpha-TCP-i following enucleation of the left eye. The clinical assessment was undertaken daily during the first 15 days, followed by fortnightly assessment until the end of the study period. For the morphological analysis, exenteration was performed in 3 animals per experimental period (15, 45, 90 and 180 days). The external and internal surfaces of the implant appeared solid, smooth and compact, with six channels which interconnected centrally. The micro-architecture was characterized by the formation of columns of hexagonal crystals. No signs of infection, exposure, dehiscence of sutures or extrusion of the implant were noted in any of the animals during the entire period of the study. The morphological evaluation demonstrated the presence of a thin capsule around the implant, from whence appeared fibro-vascular projections, which penetrated it through the interconnecting channels. In the first days after the insertion of the implant, an intense inflammatory reaction was noted. At 180 days, however, there were no signs of inflammation. The alpha-tricalcium phosphate cement implant was well tolerated in this rabbit model and appeared to be relatively inert with some fibrovascular ingrowth through the large channels.

Load-application devices: a comparative strain gauge analysis

In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM.

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

Pós-graduação em Odontologia Restauradora - ICT

Influência do tempo de endurecimento no comportamento físico e biológico de sete cimentos endodônticos

Pós-graduação em Odontologia Restauradora - ICT

Avaliação do efeito osteoindutivo do PDGF-BB associado a diferentes carreadores na regeneração óssea em cavidades cirurgicamente criadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação eletromiográfica dos músculos masseter e temporal, força de mordida e qualidade de vida em pacientes desdentados antes, durante e após a instalação e adaptação de novas próteses - total maxilar e overdenture mandibular sobre implante

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fixação do enxerto ósseo autógeno em bloco com adesivos a base de cianoacrilato ou parafuso de titânio: estudo histológico em coelhos

Pós-graduação em Odontologia - FOA

Influência de tratamentos de superfície e agentes cimentantes na sobrevivência de coroas de Y-TZP recobertas por porcelana

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

Pinos transcorticais e gesso associados à aplicação local de plasma rico em plaquetas no tratamento de fratura do III metatarsiano em potro

In horses less than one year of age fractures of the third metacarpal bone (McIII) or metatarsal bone III (MtIII) are mainly attributed to trauma. Open reduction and internal fixation are the most common treatment method. A Quarter Horse filly with three months of age, which weighed 150kg presented a diaphyseal multifragmentar wedge fracture of right MtIII which was treated with transcortical pins and cast, associated with intralesional application of platelet rich plasma (PRP). After two years of surgery, the animal initiated a training program for racing, and six months later, the patient ran its first official match. The choice of therapeutic methods for treating fractures in horses should be one that provides an earlier repair and minor possibility of complications. Thus, the therapy association which was adopted was considered favorable, since allowed full reestablishment of locomotion of the patient and made possible its return to race.

Histomorphometric analysis of pure titanium implants with porous surface versus rough surface

The purpose of this study was to analyze the bone repair around commercially pure titanium implants with rough and porous surface, fabricated using powder metallurgy technique, after their insertion in tibiae of rabbits. Seven male rabbits were used. Each animal received 3 porous-surface implants in the left tibia and 3 rough-surface implants in the right tibia. The rabbits were sacrificed 4 weeks after surgery and fragments of the tibiae containing the implants were submitted to histological and histomorphometric analyses to evaluate new bone formation at the implant-bone interface. Means (%) of bone neoformation obtained in the histomorphometric analysis were compared by Student's t-test for paired samples at 5% significance level.. The results of the histological analysis showed that osseointegration occurred for both types of implants with similar quality of bone tissue. The histomorphometric analysis revealed means of new bone formation at implant-bone interface of 79.69 ± 1.00% and 65.05 ± 1.23% for the porous- and rough-surface implants, respectively. Statistically significant difference was observed between the two types of implants with respect to the amount new bone formation (p<0.05). In conclusion, the porous-surface implants contributed to the osseointegration because they provide a larger contact area at implant-bone interface.

Como as novas mídias constroem o corpo contemporâneo

O presente trabalho buscou relacionar as novas mídias e o corpo contemporâneo juntamente com a tecnologia, isso foi desenvolvido através de uma pesquisa bibliográfica e descritiva. Foram usados buscadores eletrônicos para a consulta dos produtos científicos e acadêmicos, além dos itens convencionais de pesquisa, tais como, dissertações, teses e afins. Depois de feita toda a revisão com o material adequado e apoiada na literatura atual, consegui-se concluir que o corpo contemporâneo quando relacionado com as novas mídias atravessa não só o processo de transformação usual, mas o que vale ser destacado é a velocidade das mutações corporais que estes novos meios de comunicação exercem sobre os corpos atuais. Quando o foco passa para o corpo tecnológico, temos que este corpo é representado por uma espécie de maquina humana, que através de seus implantes e principalmente da biocompatibilidade da medicina se torna realidade na vida cotidiana e passa a despertar cada vez mais a atenção dos estudiosos do tema, outro ponto de destaque foi as duvidas e inquietações que as temáticas trouxeram ao mesmo tempo em que estas podem servir como desafio e impulsionar novos trabalhos nessa área

Adesivos multi-uso-avaliação da resistência adesiva a dentina frente a teste de cisalhamento, estereomicroscopia e microscopia eletrônica de varredura

Recent bonding systems have been advocated as multi-purpose bonding agents. The aim of this study was to determine if some of these bonding systems could be associated to composite resins from different manufacturers. This investigation was conducted to test lhe shear bond strength of three bonding systems: Scotchbond Multi-Purpose (3M Dental Products), Optibond Light Cure (Kerr) and Optibond Dual Cure (Kerr), when each of them was associated to lhe composite resins: Z1 00 (3M Dental Products), Prisma - APH (Dentsply) and Herculite XRV (Kerr). Seventy-two flat dentin bonding sites were prepared to 600 grit on human premolars mounted using acrilic resins. The teeth were assigned at random to 9 groups of 8 samples each. A split die with a 3mm diameter was placed over lhe surface of lhe dentin treated with one of lhe adhesive systems, and lhe selected composite resin was inserted and light cured. The split mold was removed and all samples were termocycled and stored in 37ºC water for 24 hours before testing. Shear bond strength was determined using an lnstron Universal testing machine. Some failures were examined under lhe S.E.M. Data was analysed by one-way analysis of variance, that demonstrated a significant difference (p<0,05) in the mean shear bond strength among Optibond Light Cure (15,446 MPa), Scotchbond Multi-Purpose (13,339 MPa) and Optibond Dual Cure (10,019 MPa). These values did not depend on the composite resin used. The association between bonding system/composite resin was statistycally significant (p<0,05) and the best results were obtained when the composite resins Z100 and Herculite were used with the adhesive system Optibond Light Cure, and when the composite resin APH was used with the adhesive system Scotchbond Multi-Purpose