Extensometria: estudo das microdeformações ao redor de três implantes de hexágono interno, com posicionamento linear, sob a influência da fundição de coifas plásticas e usinadas

The objective of this in vitro study was quantify the micro strain development around the internal hexagon implants, varying the type of prosthetic coping. For This reason, three implants of internal hexagon were inserted into one polyurethane block in line placement. Microunit abutments were screwed onto the implants. Tangentially the implants were bonded the strain gauges, two to the center implant. Ten structures, each one containing three copings were cast in Co-Cr alloy, that were divided into groups in the first group, plastic copings were used, and in the second group machined copings were used. The superstructure’s occlusal screws were tightened onto Microunit abutments with 10 Ncm torque, the magnitude of micro strain was recorded. The mean values of each strain gauge of each plastic copings were 363,37 ± 237,66 and the machined copings were 338,12 ± 223,01. The data were analyzed statistically by t- Student test. No statistically significant difference was found between the prosthetic copings (p= 0,867). It was concluded that to internal hexagon implants in line placement, the type of copings presented similar magnitude of micro strain after prosthetic occlusal screw was tightened

Sobre a dinâmica de rotação de um planeta através de um sistema médio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da influência do formato da porca e da pré-carga em juntas aparafusadas em tração

Many structures and mechanical equipment requires a union member, and the screw is one of the most used, the cost is low, it is versatile and easy to find on the market. The resulting pre-load assembly torque associated with the cyclical external load has great influence, so it will be studied carefully. This study analyzed some of these factors, as the format of nuts, and the washer material when they are incompatible with the bolt material can cause a reduction in life of the joint fatigue

Análise das microdeformações geradas ao redor de implantes de hexágono externo sob a aplicação de cargas verticais em pilares microunit retos e angulados

Pós-graduação em Odontologia Restauradora - ICT

Avaliação in vitro das microdeformações em implantes curtos, com conexão protética cone morse e diferentes desenhos de roscas, convencionais e platôs

Pós-graduação em Odontologia Restauradora - ICT

Pesquisa de genomas virais em primatas não humanos do novo mundo por metagenômica

Pós-graduação em Medicina Veterinária - FMVZ

Analysis of implants with laser irradiated surface and silicate deposition

Objectives: the purpose of this study was to evaluate the surfaces of commercially pure titanium (cpTi) implants surface modified by laser beam (LS), by laser beam associated with sodium silicate deposition (SS) and compare them with surfaces modified by dual-acid etched (AS) and with machined surface (MS). Methods: thirty rabbits received two implants each (one for each tibia). After 30, 60 and 90 days postoperative, the implants were removed by reverse torque for biomechanical analysis and surfaces were analyzed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). Results: the mean values of reverse torque at 30, 60 and 90 days postoperative were respectively 24.60, 43.60 e 60.40 N.cm to MS, 43.00, 68.20 e 63.80 N.cm to AS group, 59.80, 76.60 e 78.00 N.cm to LS group and 63.00, 75.40 e 76.60 N.cm to SS group. At 30 days, LS and SS groups showed statistically significant difference (p<0.05) compared to the other groups. At 60 days, LS and SS groups showed statistically significant difference (p<0.05) when compared to MS. Conclusions: it was concluded that SL and SS implants' biomechanical and topographical properties increased bone-implant interaction when compared to the AS and MS implants.

Efeito da aplicação de filmes de carbono tipo diamante por plasma no destorque de pilares de implantes com conexões cônicas internas

Pós-graduação em Odontologia Restauradora - ICT

Efeito da administração de alendronato, a longo prazo, sobre as propriedades mecânicas do tecido ósseo, sua reparação e mineralização ao redor de implantes osseointegráveis. Estudo em ratas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de parafuso de interferência bioabsorvível para cirurgia de joelho em PLDL (poli ácido lático) e compósito PLDL + βTCP (beta trifosfato de cálcio)

Pós-graduação em Engenharia Mecânica - FEB

Carbono tipo diamante em componentes de implantes dentários: avaliação das propriedades antimicrobianas e de adesão de Escherichia coli

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência dos parâmetros de projeto em um motor a combustão interna

This paper discusses the influence of the design parameters in the operation and construction of an internal combustion engine. A theoretical analysis was developed using a standard crank-connecting rod-piston to verify the behavior of the stresses generated in the combustion and transformed into rotational energy of the crank shaft. Design parameters directly influence not only the final result of the characteristics of power and torque, but how the engine must be built to withstand different loads. The choice of parameters of a combustion engine is directly linked with the application of the engine and the final result expected of it function

Relationship between the surface chemical composition of implants and contact with the substrate

The purpose of the study was to use scanning electron microscopy and energy dispersive x-ray spectrometry to assess possible morphologic and chemical changes after performing double-insertion and pullout tests of implants of different shapes and surface treatments. Four different types of implants were used—cylindrical machined-surface implants, cylindrical double-surface–treated porous implants, cylindrical surface-treated porous implants, and tapered surface-treated porous implants—representing a total of 32 screws. The implants were inserted into synthetic bone femurs, totaling 8 samples, before performing each insertion with standardized torque. After each pullout the implants were analyzed by scanning electron microscopy and energy dispersive x-ray spectrometry using a universal testing machine and magnified 35 times. No structural changes were detected on morphological surface characterization, only substrate accumulation. As for composition, there were concentration differences in the titanium, oxygen, and carbon elements. Implants with surface acid treatment undergo greater superficial changes in chemical composition than machined implants, that is, the greater the contact area of the implant with the substrate, the greater the oxide layer change. In addition, prior manipulation can alter the chemical composition of implants, typically to a greater degree in surface-treated implants.

Effect of splinting in accuracy of two implants impression techniques

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

Reabilitação estético-funcional sobre implantes agulhados e endósseos

This report shows the resolution of a case study whose aim was promote the aesthetic and functional rehabilitation of upper left hemi-arch over endosseous and needle implant prostheses. To improve the position of the needle implants, we performed the bucco-palatal bending of needles splinting them with composite resin; we removed the screwed implant prosthesis in the regions of the premolars (24 and 25) and molar (26). The mini-abutments of the last two implants were replaced, and in the first premolar and canine, we used cemented abutments due to implant angulation having planned soldering because of implant size and contact with one needle implant that could interfere with intimate contact bone/implant damaging biomechanics. Pick-up impressions were performed with an open tray, using a retractor cord in the needle implants and respective transfer copings. Therefore, models were related on semi-adjustable articulator after a face-bow recording and interocclusal indexes. After working cast fabrication and try-in of infra-structures, these were adjusted and related into the articulator again. Then, after ceramic build-up, adjustments, finishing, and torque, chemically-activated resin cement was applied on units 21 to 24. At the end of the case, we concluded that a good aesthetic and functional rehabilitation depends on thorough knowledge of techniques for each clinical situation.