Reabilitação de maxila atrófica com tecido ósseo homógeno e prótese fixa implantossuportada

The techniques of bone reconstruction for atrophic maxillae have been improved in order to promote bone tissue growth in both height and thickness. The grafts performed with use of autogenous bone is considered the gold standard by most researchers, for demonstrating osteogenic capacity and not to promote antigenic response. However, this type of grafting is not possible to get bone tissue in large quantity for extensive renovations. In recent years, alternatives have been researched to overcome the limitations of autogenous bone. Several alternatives have been investigated to supply the disadvantages of autogenous bone grafts. In such studies, allogeneic bone grafts which are obtained from individuals with different genetic load, but from the same species have been extensively used. They can be indicated in cases of arthrosplasty, surgical knee reconstruction, and large bone defects as well as in oral and maxillofacial reconstruction. Besides showing great applicability and biocompatibility, this type of bone is available in unlimited quantities. To rehabilitate atrophic maxillae an option that has been performed with high success rate is the reconstruction with bone graft followed by osseointegrated dental implants to rehabilitate the patient aesthetics and functionally. This paper aims to show the feasibility of allogenic bone as material for reconstruction of atrophic maxilla, and subsequent rehabilitation with metal ceramic fixed prosthesis implant and dental restoration with accompanying three years through literature review and clinical case report.

Avaliação microscópica da propriedade biológica e da biocompatibilidade do osso composto e do osso integral de origem bovina

The aim of this study was to evaluate the biological properties and biocompatibility of bovine non-demineralized lyophilized and composite bones implanted in tibiae bone cavities and at the subcutaneous level. Twenty-four rats were used and sacrificed 15 and 45 days later. At the subcutaneous level, after 15 days an inflammatory reaction was seen around biomaterial particles with the presence of giant cells and at 45 days fibrous connective tissue had also developed. No signs of ectopic bone formation were observed at tibiae regions; more bone neoformation was observed at the control group (15 days) with 42.8% of the outer cortex layer against 22.6% at Orthogen and 25% at GenMix groups. At 45 days, correspondent values for bone neoformation were 62.5% at control, 26% at Orthogen, and 35% at GenMix groups, respectively. It can be concluded that both materials tested were biocompatible aiming to bone neoformation by their osteoconductive properties with no ectopic formation sites observed.

Diffusion of oxygen in Ti-15Mo-xZr alloys studied by anelastic spectroscopy

Because of their low elasticity modulus, titanium alloys have excellent biocompatibility, and are largely used in orthopedic prostheses. Among the properties that are beneficial for use in orthopedic implants is the elasticity modulus, which is closely connected to the crystal structure of the material. Interstitial elements, such as oxygen, change the mechanical properties of the material. Anelastic spectroscopy measurements are a powerful tool for the study of the interaction of these elements with the metallic matrix and substitutional solutes, providing information on the diffusion and concentration of interstitial elements. In this study, the effect of oxygen on the anelastic properties of alloys in the Ti-15Mo-Zr system was analyzed using anelastic spectroscopy measurements. The diffusion coefficients, pre-exponential factors, and activation energies of these alloys were calculated for oxygen.

Effect of heat treatment on microstructure and mechanical properties of Ti-5wt-%Ni alloys for use as biomaterial

Titanium alloys are among the most important and frequently used class of biomaterials. In addition to biocompatibility, it is important that an implant material present satisfactory mechanical properties that allow long term use in the body. To improve such properties, different heat treatments are used, as well as doping with oxygen. The presence of interstitial oxygen in the crystal lattice causes deformation, increases the hardness, and causes modifications in anelasticity, thereby decreasing the elastic modulus. In this study, an alloy was prepared by arc melting precursor metals, heat and mechanically treated, and doped with oxygen, resulting in samples with different processing conditions. In each condition, the alloy was characterised in terms of amount of oxygen, X-ray diffraction, and optical microscopy. In addition, properties of the alloy, such as hardness and elastic modulus, were analysed.

Influences of the pH on the adsorption properties of an antimicrobial peptide on titanium surfaces

The adsorption behavior of the Tet-124 antimicrobial peptide and the Tet-124 peptide modified at the C- and N-terminus with the sequence glycine-3,4-dihydroxyphenylalanine-glycine (G-DOPA-G) on titanium surfaces was studied using quartz crystal micro balance with dissipation (QCM-D). At a low pH level (4.75) Tet-124 and Tet-124-G-DOPA-G form rigid layers. This is attributed to the electrostatic interactions of the positively charged lysine and arginine residues in the peptide sequence with the negatively charged titanium oxide layer. At an elevated pH level (6.9) Tet-124 shows a lower mass adsorption at the surface than Tet-124-G-DOPA-G. This is attributed to the interaction of the catechol due to the formation of complexes with the titanium oxide and titanium surface layer. The C terminal and N terminal modification with the sequence G-DOPA-G shows similar adsorption rate and mass adsorption coverage at saturation; however it is presented a more loosely layers on the G-DOPA-G-TeT-124. Fibroblast adhesion and the biocompatibility test of both the surfaces following modification with Tet-124-G-DOPA-G and the titanium alloy control showed similar results. In addition, no changes in the adhesion of E. coli bacteria due to the modification of the surface were detected.

Diffusion of oxygen in some binary Ti-Based alloys used as biomaterials

Ti and its alloys are widely used as biomaterials. Their main properties are excellent corrosion resistance, relatively low elastic modulus, high specific strength, and good biocompatibility. The development of new Ti alloys with properties favorable for use in the human body is desired. To this end, Ti alloys with Mo, Nb, Zr, and Ta are being developed, because these elements do not cause cytotoxicity. The presence of interstitial elements (such as oxygen and nitrogen) induces strong changes in the elastic properties of the material, which leads to hardening or softening of the alloy. By means of anelastic spectroscopy, we are able to obtain information on the diffusion of these interstitial elements present in the crystalline lattice. In this paper, the effect of oxygen on the anelastic properties of some binary Ti-based alloys was analyzed with anelastic spectroscopy. The diffusion coefficients, pre-exponential factors, and activation energies were calculated for oxygen and nitrogen in these alloys.

Effect of the substitutional elements on the microstructure of the Ti-15Mo-Zr and Ti-15Zr-Mo systems alloys

Titanium alloys have excellent biocompatibility, and combined with their low elastic modulus, become more efficient when applied in orthopedic prostheses. Samples of Ti-15Mo-Zr and Ti-15Zr-Mo system alloys were prepared using an arc-melting furnace with argon atmosphere. The chemical quantitative analysis was performed using an optical emission spectrometer with inductively coupled plasma and thermal conductivity difference. The X-ray diffractograms, allied with optical microscopy, revealed the structure and microstructure of the samples. The mechanical analysis was evaluated by Vickers microhardness measurements. The structure and microstructure of alloys were sensitive to molybdenum and zirconium concentration, presenting α′, α″ and β phases. Molybdenum proved to have greater β-stabilizer action than zirconium. Microhardness was changed with addition of molybdenum and zirconium, having Ti-15Zr-10Mo (436 ± 2 HV) and Ti-15Mo-10Zr (378 ± 4 HV) the highest values in each system.

Síntese e caracterização de matrizes híbridas para aplicação em sistemas de liberação controlada

Pós-graduação em Ciência dos Materiais - FEIS

Estudo da incorporação e liberação de peptídeos hormonais utilizando membranas de látex natural como carreador

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito dos parâmetros de retificação no acabamento superficial de cerâmicas aplicadas à biomateriais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento e caracterização de ligas de Co-Cr-Mo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito in vivo da deposição de filmes de DLC com e sem nanopartículas de prata sobre liga de titânio para utilização em próteses articulares

Pós-graduação em Biopatologia Bucal - ICT

Efeito de biomateriais no crescimento e funcionalidade de células progenitoras da polpa dentária

Pós-graduação em Odontologia Restauradora - ICT

Abordagem alternativa para síntese de melanina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propriedades físicas, químicas, antimicrobianas e biológicas de cimentos endodônticos com óxido de cálcio e resina salicilato

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)