RESUMO
A reabilitação protética por meio de implantes tem se confi gurado como o padrão-ouro para a devolução da função previamente perdida pelo paciente, podendo ser realizada com próteses removíveis ou fixas sobre os implantes osseointegrados. As próteses fixas do tipo protocolo proporcionam maior estabilidade durante as atividades cotidianas, como falar e comer, além de alta performance estética, quando bem indicada. Vislumbrando uma maior resistência das próteses, melhor harmonização do sorriso e adequada adaptação, as infraestruturas em zircônia vêm sendo altamente difundidas na literatura. Confeccionadas pelo método CAD/CAM, as próteses em zircônia dispensam as etapas de solda, o que elimina possíveis distorções de grandes estruturas, além de serem produzidas mais rapidamente e com uma estética maior, caracterizando-se como a melhor opção para pacientes que buscam a mimetização do sorriso natural.
The prosthetic rehabilitation using dental implants has been featured as the gold standard for retrieving patient's lost function, and may be performed by implant-supported removable or fixed dental prostheses. The implant-supported fixed prosthesis provides greater stability during daily activities, such as talking and eating, and high aesthetic performance, when properly indicated. In order to obtain higher resistance, superior smile esthetics and adequate prosthesis fit, the zirconia infrastructure have been highly disseminated in the literature. The CAD/CAM zirconia prosthesis avoids welding/soldering, which eliminates possible distortions of large structures. In addition, it is produced faster and with greater aesthetic, being nowadays characterized as the best option for patients who seek to emulate the natural smile.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Desenho Assistido por Computador , Implantação Dentária , Prótese Dentária Fixada por Implante , Prótese Total , Tecnologia Odontológica , ZircônioRESUMO
A reabilitação fixa de pacientes desdentados totais com próteses conhecidas como protocolo de Brånemark é uma alternativa indicada com grande previsibilidade e um bom prognóstico nas reabilitações com implantes osseointegrados. Essas próteses proporcionam maior eficiência mastigatória, conforto e estética, quando comparadas a próteses removíveis convencionais. Tradicionalmente, essa modalidade reabilitadora protética é confeccionada com dentes e gengiva em resina acrílica, o que favorece o acúmulo de biofilme. Além disso, apresentam degradação e desgaste, principalmente dos dentes, o que contribui para a perda da dimensão vertical de oclusão e perda da estabilidade oclusal. No intuito do controle das desvantagens apresentadas, uma alternativa utilizada é a individualização dos dentes com coroas cerâmicas. As coroas individuais, além de atribuírem melhor estética para a reabilitação, também são responsáveis por melhor passividade, longevidade, possibilidade de reparos e estabilidade oclusal.
The rehabilitation of completely edentulous patients with fixed restorations known as Brånemark protocol is an alternative with great predictability and good prognosis in the field of dental implants. These restorations provide better masticatory efficiency, comfort, and esthetics, when compared to the conventional removable dentures. In general, this prosthetic modality receives artificial gingiva and acrylic teeth, which favors plaque buildup. besides, degradation and wear can be seen, particularly at teeth, contributing to the loss of vertical occlusal dimension and stability. For this, an alternative is to provide individual ceramic crowns. Besides providing better esthetics, passivity, longevity, stability, and the chance of repair are possible in this scenario.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Coroas , Implantação Dentária , Prótese Dentária Fixada por Implante , Prótese Total , Estética Dentária , Reabilitação BucalRESUMO
The aim of this study was to evaluate by photoelastic analysis stress distribution on short and long implants of two dental implant systems with 2-unit implant-supported fixed partial prostheses of 8 mm and 13 mm heights. Sixteen photoelastic models were divided into 4 groups: I: long implant (5 × 11 mm) (Neodent), II: long implant (5 × 11 mm) (Bicon), III: short implant (5 × 6 mm) (Neodent), and IV: short implants (5 × 6 mm) (Bicon). The models were positioned in a circular polariscope associated with a cell load and static axial (0.5 Kgf) and nonaxial load (15°, 0.5 Kgf) were applied to each group for both prosthetic crown heights. Three-way ANOVA was used to compare the factors implant length, crown height, and implant system (α = 0.05). The results showed that implant length was a statistically significant factor for both axial and nonaxial loading. The 13 mm prosthetic crown did not result in statistically significant differences in stress distribution between the implant systems and implant lengths studied, regardless of load type (P > 0.05). It can be concluded that short implants showed higher stress levels than long implants. Implant system and length was not relevant factors when prosthetic crown height were increased.
RESUMO
Conventional tilted implants are used in oral rehabilitation for heavily absorbed maxilla to avoid bone grafts; however, few research studies evaluate the biomechanical behavior when different angulations of the implants are used. The aim of this study was evaluate, trough photoelastic method, two different angulations and length of the cantilever in fixed implant-supported maxillary complete dentures. Two groups were evaluated: G15 (distal tilted implants 15°) and G35 (distal tilted implants 35°) n = 6. For each model, 2 distal tilted implants (3.5 x 15 mm long cylindrical cone) and 2 parallel tilted implants in the anterior region (3.5 x 10 mm) were installed. Photoelastic models were submitted to three vertical load tests: in the end of cantilever, in the last pillar and in the all pillars at the same time. We obtained the shear stress by Fringes software and found values for total, cervical and apical stress. The quantitative analysis was performed using the Student tests and Mann-Whitney test; p ≥ 0.05. There is no difference between G15 and G35 for total stress regardless of load type. Analyzing the apical region, G35 reduced strain values considering the distal loads (in the cantilever p = 0.03 and in the last pillar p = 0.02), without increasing the stress level in the cervical region. Considering the load in all pillars, G35 showed higher stress concentration in the cervical region (p = 0.04). For distal loads, G15 showed increase of tension in the apical region, while for load in all pillars, G35 inclination increases stress values in the cervical region.
Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante/métodos , Prótese Total Superior , Módulo de Elasticidade , Análise do Estresse Dentário , Planejamento de Dentadura , Humanos , Teste de Materiais , Modelos Biológicos , Valores de Referência , Resistência ao Cisalhamento , Estatísticas não Paramétricas , Estresse Mecânico , Fatores de TempoRESUMO
Objetivo: presentar un caso de rehabilitación con implante único en el maxilar anterior con un abutment de zirconia personalizado y mostrar que la elección de este material constituye una opción para conseguir la armonía de la sonrisa. Caso clínico: un paciente de sexo masculino, de 28 años de edad, consultó en busca de una alternativa para llenar la ausencia de la pieza 11, dado que la prótesis que llevaba era estéticamente insatisfactoria. El abutment fue confeccionado en el centro de mecanizado Cubo (San Pablo, Brasil). El índice del abutment synOcta (Straumann Brasil, San Pablo, Brasil) fue escaneado con el programa Dental Wings Client v.2.0.1 (Henry Schein Company, Melville, NY, Estados Unidos). La corona y la carilla libre de metal de disilicato de litio, le otorgaron armonía, forma, color, textura superficial y translucidez incisal, respecto a la pieza dentaria contralateral. Conclusión: los abutments de zirconia constituyen una alternativa útil en los casos que requieren estética, pues proporcionan un color satisfactorio y acorde a la sonrisa, además de una mayor resistencia a la fractura, lo cual elimina la necesidad del empleo de metal.
Assuntos
Humanos , Masculino , Adulto , Dente Suporte , Implantes Dentários para Um Único Dente , Estética Dentária , Incisivo , Zircônio , Facetas Dentárias , Compostos de Lítio , Reabilitação Bucal , SorrisoRESUMO
Objetivo: presentar un caso de rehabilitación con implante único en el maxilar anterior con un abutment de zirconia personalizado y mostrar que la elección de este material constituye una opción para conseguir la armonía de la sonrisa. Caso clínico: un paciente de sexo masculino, de 28 años de edad, consultó en busca de una alternativa para llenar la ausencia de la pieza 11, dado que la prótesis que llevaba era estéticamente insatisfactoria. El abutment fue confeccionado en el centro de mecanizado Cubo (San Pablo, Brasil). El índice del abutment synOcta (Straumann Brasil, San Pablo, Brasil) fue escaneado con el programa Dental Wings Client v.2.0.1 (Henry Schein Company, Melville, NY, Estados Unidos). La corona y la carilla libre de metal de disilicato de litio, le otorgaron armonía, forma, color, textura superficial y translucidez incisal, respecto a la pieza dentaria contralateral. Conclusión: los abutments de zirconia constituyen una alternativa útil en los casos que requieren estética, pues proporcionan un color satisfactorio y acorde a la sonrisa, además de una mayor resistencia a la fractura, lo cual elimina la necesidad del empleo de metal.(AU)
Assuntos
Humanos , Masculino , Adulto , Dente Suporte , Zircônio , Estética Dentária , Implantes Dentários para Um Único Dente , Incisivo , Sorriso , Facetas Dentárias , Compostos de Lítio , Reabilitação BucalRESUMO
This report presents a prosthetic technique for the improvement of surgically positioned, buccally placed zygomatic implants with the use of custom abutments for improved retention screw position and an esthetic implant reconstruction. The patient presented four zygomatic implants with pronounced buccal inclination. The anterior implants were inclined toward the location where the anterior artificial teeth should be placed during rehabilitation. As the manufacturer does not provide angulated abutments, we attempted the waxing and overcasting of a prosthetic abutment, repositioning the access holes of the prosthetic screws to a more palatal position. This clinical report demonstrates that abutment customization could be an interesting way to relocate the access holes of the prosthetic screws in cases of zygomatic implants with pronounced buccal inclination.
Assuntos
Projeto do Implante Dentário-Pivô , Implantes Dentários , Planejamento de Dentadura , Zigoma/cirurgia , Atrofia , Ligas de Cromo/química , Bases de Dentadura , Prótese Total Superior , Feminino , Seguimentos , Humanos , Registro da Relação Maxilomandibular , Arcada Edêntula/reabilitação , Maxila/patologia , Pessoa de Meia-Idade , Dente Artificial , Resultado do TratamentoRESUMO
This study evaluated the tensile and flexural strength of tungsten inert gas (TIG) welds in specimens made of commercially pure titanium (CP Ti) compared with laser welds. Sixty cylindrical specimens (2 mm diameter x 55 mm thick) were randomly assigned to 3 groups for each test (n=10): no welding (control), TIG welding (10 V, 36 A, 8 s) and Nd:YAG laser welding (380 V, 8 ms). The specimens were radiographed and subjected to tensile and flexural strength tests at a crosshead speed of 1.0 mm/min using a load cell of 500 kgf applied on the welded interface or at the middle point of the non-welded specimens. Tensile strength data were analyzed by ANOVA and Tukey's test, and flexural strength data by the Kruskal-Wallis test (α=0.05). Non-welded specimens presented significantly higher tensile strength (control=605.84±19.83) (p=0.015) and flexural strength (control=1908.75) (p=0.000) than TIG- and laser-welded ones. There were no significant differences (p>0.05) between the welding types for neither the tensile strength test (TIG=514.90±37.76; laser=515.85±62.07) nor the flexural strength test (TIG=1559.66; laser=1621.64). As far as tensile and flexural strengths are concerned, TIG was similar to laser and could be suitable to replace laser welding in implant-supported rehabilitations.
Este estudo avaliou a resistência à tração e à flexão de soldas feitas com gás inerte de tungstênio (TIG) em amostras de titânio comercialmente puro (Ti CP) em comparação com a solda a laser. Sessenta amostras cilíndricas (diâmetro de 2 mm e espessura de 55 mm) foram distribuídas aleatoriamente em três grupos para cada ensaio (n=10): sem solda (controle), solda TIG (10V, 36A, 8 s) e solda com laser de Nd:YAG (380 V, 8 ms). As amostras foram radiografadas e submetidas aos testes de resistência à tração e à flexão em máquina de ensaios mecânicos à velocidade de 1mm/min com célula de carga de 500 kgf aplicada na interface soldada ou no ponto médio das amostras controle. Os dados de resistência à tração foram analisados estatisticamente por ANOVA e teste de Tukey e os dados de resistência à flexão pelo teste de Kruskal-Wallis (α=0,05). Espécimes não-soldados apresentaram resistência à tração (controle=605,84±19,83) (p=0,015) e resistência à flexão (controle=1908,75) (p=0,000) significantemente maiores que os solados com TIG ou laser. Não houve diferença estatisticamente significante (p>0.05) entre os tipos de solda no teste de resistência à tração (TIG=514,90±37,76; laser=515,85±62,07) nem no teste de resistência à flexão (TIG=1559,66; laser=1621,64). As resistências à tração e à flexão foram similares quando as amostras foram soldadas com TIG e a laser.
Assuntos
Lasers , Tungstênio , Titânio/química , Soldagem/métodos , Porosidade , Resistência ao Cisalhamento , Resistência à TraçãoRESUMO
Lack of passivity has been associated with biomechanical problems in implant-supported prosthesis. The aim of this study was to evaluate the passivity of three techniques to fabricate an implant framework from a Co-Cr alloy by photoelasticity. The model was obtained from a steel die simulating an edentulous mandible with 4 external hexagon analog implants with a standard platform. On this model, five frameworks were fabricated for each group: a monoblock framework (control), laser and TIG welding frameworks. The photoelastic model was made from a flexible epoxy resin. On the photoelastic analysis, the frameworks were bolted onto the model for the verification of maximum shear stress at 34 selected points around the implants and 5 points in the middle of the model. The stresses were compared all over the photoelastic model, between the right, left, and center regions and between the cervical and apical regions. The values were subjected to two-way ANOVA, and Tukey's test (α=0.05). There was no significant difference among the groups and studied areas (p>0.05). It was concluded that the stresses generated around the implants were similar for all techniques.
Assuntos
Ligas de Cromo/química , Prótese Dentária Fixada por Implante , Soldagem em Odontologia/métodos , Lasers , Gases em Plasma , Técnica de Fundição Odontológica , Projeto do Implante Dentário-Pivô , Implantes Dentários , Soldagem em Odontologia/instrumentação , Resinas Epóxi/química , Humanos , Arcada Edêntula/reabilitação , Mandíbula/patologia , Teste de Materiais , Modelos Dentários , Estresse Mecânico , Propriedades de Superfície , Soldagem/instrumentação , Soldagem/métodosRESUMO
Lack of passivity has been associated with biomechanical problems in implant-supported prosthesis. The aim of this study was to evaluate the passivity of three techniques to fabricate an implant framework from a Co-Cr alloy by photoelasticity. The model was obtained from a steel die simulating an edentulous mandible with 4 external hexagon analog implants with a standard platform. On this model, five frameworks were fabricated for each group: a monoblock framework (control), laser and TIG welding frameworks. The photoelastic model was made from a flexible epoxy resin. On the photoelastic analysis, the frameworks were bolted onto the model for the verification of maximum shear stress at 34 selected points around the implants and 5 points in the middle of the model. The stresses were compared all over the photoelastic model, between the right, left, and center regions and between the cervical and apical regions. The values were subjected to two-way ANOVA, and Tukey's test (α=0.05). There was no significant difference among the groups and studied areas (p>0.05). It was concluded that the stresses generated around the implants were similar for all techniques.
Resumo A falta de passividade tem sido associada a problemas biomecânicos em próteses implantossuportadas. A proposta deste estudo foi avaliar, por meio da fotoelasticidade, a influência de três diferentes de fabricação de infraestrutura em liga de Co-Cr na passividade destas. O modelo foi obtido a partir de uma matriz de aço simulando uma mandíbula edêntula com 4 análogos de implantes de hexágono externo com plataforma padrão. Neste modelo, foram confeccionados cinco amostras para cada grupo: infraestruturas em monobloco, infraestruturas soldadas a laser e soldadas a TIG. O modelo fotoelástico foi feito com uma resina epóxi flexível (GIII, Polipox Industria e Comercio Ltda.). Na análise fotoelástica, as infraestruturas foram aparafusadas no modelo para a verificação da tensão de cisalhante máxima em 34 pontos selecionados ao redor dos implantes e 5 pontos na região média do modelo. Foram comparadas as tensões em todo o modelo fotoelástico, entre as regiões direita, esquerda e centro e também entre as regiões cervical e apical. Os valores foram submetidos à análise de variância a dois critérios, seguido pelo teste de Tukey (α=0,05). Os resultados não mostraram diferença significativa entre as tensões presentes nos grupos e nas áreas estudadas. Conclui-seque as tensões geradas ao redor dos implantes foram semelhantes entre as diferentes técnicas de confecção e entre todas as regiões analisadas. .
Assuntos
Humanos , Ligas de Cromo/química , Prótese Dentária Fixada por Implante , Soldagem em Odontologia/métodos , Lasers , Gases em Plasma , Técnica de Fundição Odontológica , Projeto do Implante Dentário-Pivô , Implantes Dentários , Modelos Dentários , Soldagem em Odontologia/instrumentação , Resinas Epóxi/química , Arcada Edêntula/reabilitação , Teste de Materiais , Mandíbula/patologia , Estresse Mecânico , Propriedades de Superfície , Soldagem/instrumentação , Soldagem/métodosRESUMO
This study evaluated the tensile and flexural strength of tungsten inert gas (TIG) welds in specimens made of commercially pure titanium (CP Ti) compared with laser welds. Sixty cylindrical specimens (2 mm diameter x 55 mm thick) were randomly assigned to 3 groups for each test (n=10): no welding (control), TIG welding (10 V, 36 A, 8 s) and Nd:YAG laser welding (380 V, 8 ms). The specimens were radiographed and subjected to tensile and flexural strength tests at a crosshead speed of 1.0 mm/min using a load cell of 500 kgf applied on the welded interface or at the middle point of the non-welded specimens. Tensile strength data were analyzed by ANOVA and Tukey's test, and flexural strength data by the Kruskal-Wallis test (α=0.05). Non-welded specimens presented significantly higher tensile strength (control=605.84 ± 19.83) (p=0.015) and flexural strength (control=1908.75) (p=0.000) than TIG- and laser-welded ones. There were no significant differences (p>0.05) between the welding types for neither the tensile strength test (TIG=514.90 ± 37.76; laser=515.85 ± 62.07) nor the flexural strength test (TIG=1559.66; laser=1621.64). As far as tensile and flexural strengths are concerned, TIG was similar to laser and could be suitable to replace laser welding in implant-supported rehabilitations.
Assuntos
Lasers , Titânio/química , Tungstênio , Soldagem/métodos , Porosidade , Resistência ao Cisalhamento , Resistência à TraçãoRESUMO
OBJECTIVES: This study evaluated the microleakage at the implant/abutment interface of external hexagon (eH) implants and abutments with different amounts of bacteria and tightening torques. MATERIAL AND METHODS: A bacterial suspension was prepared to inoculate the implants. The first phase of this study used nine EH implants and abutments that were divided into three groups with different amounts of bacterial suspension (n=3): V0.5: 0.5 µL; V1.0: 1.0 µL e V1.5: 1.5 µL, and tightened to the manufacturer's recommended torque. The second phase of this experiment used 27 assemblies that were similar to those used in the first phase. These samples were inoculated with 0.5 µL of bacterial suspension and divided into three groups (n=9). T10: 10 Ncm; T20: 20 Ncm and T32: 32 Ncm. The samples were evaluated according to the turbidity of the broth every 24 hours for 14 days, and the bacteria viability was tested after that period. The statistical evaluation was conducted by Kruskal-Wallis testing (p<.05). RESULTS: During the first phase, groups V1.0 and V1.5 was presented with bacterial contamination in all samples after 24 h. During the second phase, two samples from group T10 and one from T20 presented positive results for bacterial contamination. Different amounts of bacterial solution led to overflow and contamination during the first 24 h of the experiment. The tightening torques did not statistically affect the microleakage in the assemblies. However, the group that was tightened to 32 Ncm torque did not show any bacterial contamination. CONCLUSION: After 14 days of experimentation, the bacteria were proven to remain viable inside the implant internal cavity.
Assuntos
Dente Suporte/microbiologia , Projeto do Implante Dentário-Pivô/métodos , Implantes Dentários/microbiologia , Infiltração Dentária/microbiologia , Torque , Parafusos Ósseos , Escherichia coli/crescimento & desenvolvimento , Humanos , Teste de Materiais , Estatísticas não Paramétricas , Fatores de TempoRESUMO
OBJECTIVES: This study evaluated the microleakage at the implant/abutment interface of external hexagon (eH) implants and abutments with different amounts of bacteria and tightening torques. MATERIAL AND METHODS: A bacterial suspension was prepared to inoculate the implants. The first phase of this study used nine EH implants and abutments that were divided into three groups with different amounts of bacterial suspension (n=3): V0.5: 0.5 µL; V1.0: 1.0 µL e V1.5: 1.5 µL, and tightened to the manufacturer's recommended torque. The second phase of this experiment used 27 assemblies that were similar to those used in the first phase. These samples were inoculated with 0.5 µL of bacterial suspension and divided into three groups (n=9). T10: 10 Ncm; T20: 20 Ncm and T32: 32 Ncm. The samples were evaluated according to the turbidity of the broth every 24 hours for 14 days, and the bacteria viability was tested after that period. The statistical evaluation was conducted by Kruskal-Wallis testing (p<.05). RESULTS: During the first phase, groups V1.0 and V1.5 was presented with bacterial contamination in all samples after 24 h. During the second phase, two samples from group T10 and one from T20 presented positive results for bacterial contamination. Different amounts of bacterial solution led to overflow and contamination during the first 24 h of the experiment. The tightening torques did not statistically affect the microleakage in the assemblies. However, the group that was tightened to 32 Ncm torque did not show any bacterial contamination. CONCLUSION: After 14 days of experimentation, the bacteria were proven to remain viable inside the implant internal cavity.
Assuntos
Humanos , Dente Suporte/microbiologia , Projeto do Implante Dentário-Pivô/métodos , Implantes Dentários/microbiologia , Infiltração Dentária/microbiologia , Torque , Parafusos Ósseos , Escherichia coli/crescimento & desenvolvimento , Teste de Materiais , Estatísticas não Paramétricas , Fatores de TempoRESUMO
PURPOSE: This study sought to evaluate the influence of methodologic aspects on variations in the findings of in vitro microleakage studies of the implant-abutment interface. MATERIALS AND METHODS: The MEDLINE, EMBASE, and Cochrane Library databases were consulted for in vitro studies published between 1990 and August 2011. Date from the studies that met the inclusion and exclusion criteria were arranged in tables and subjected to descriptive analysis. RESULTS: Twenty-one studies were found to be eligible for the analysis after application of the inclusion/exclusion criteria. Sixteen studies used bacteria (76.2%), one used a bacterial toxin (4.76%), one used saliva (4.76%), two employed dyes (9.52%), and one used a combination of dyes and bacteria (4.76%). Eight studies evaluated microleakage from the inner portion of the implant to the external portion (38.1%) and nine examined the reverse (42.85%), while four studies investigated the relationship between them (19.05%). The volume inoculated inside the implants ranged from 0.1 to 5.0 mL. The bacterial concentrations used in the tests ranged from 2.41 x 106 to 8 x 108 colony-forming units/mL. Oral bacterial flora; mixtures of bacteria, toluidine blue, and gentian violet; and lipopolysaccharide of Salmonella enterica bacterial toxins were used. The monitoring period of test results ranged from 24 hours to 11 weeks for bacteria, 5 minutes to 7 days for dye, and 7 days for bacterial toxins. In four studies, microleakage was correlated with the size of the implant-abutment microgap. The external-hexagon implant configuration showed the greatest microleakage, followed by internal-trilobe, internal-hexagon, and internal-taper configurations. CONCLUSION: The lack of standardization hinderd comparisons of the studies and could explain the divergent results. It is suggested for future studies that special emphasis be placed upon inoculation and analysis of the specific volume for each system, lower concentrations of inoculated bacterial suspensions, and shorter follow-up time when using bacteria.
Assuntos
Dente Suporte , Projeto do Implante Dentário-Pivô , Implantes Dentários , Infiltração Dentária/diagnóstico , Carga Bacteriana/métodos , Corantes , Implantes Dentários/microbiologia , Infiltração Dentária/microbiologia , Violeta Genciana , Humanos , Polissacarídeos Bacterianos , Saliva , Salmonella enterica , Fatores de Tempo , Cloreto de TolônioRESUMO
Objetivo: avaliar por meio da fotoelasticidade, as tensões geradas ao redor de implantes após o aparafusamento de estruturas confeccionadas por soldagem a Laser ou a TIG de barras cilíndricas de Cobalto-Cromo. Metodologia: foi realizado um estudo experimental a partir de um modelo de trabalho com dois implantes rosqueáveis. Nele foram realizadas a união dos UCLAs calcináveis à barra metálica, ambos de Cobalto-Cromo, por meio de soldagens à Laser(Grupo 1) e a TIG (Grupo 2), para confecção das amostras. Em seguida, sobre um modelo fotoelástico foram parafusadas as estruturas metálicas com torque manual de 20 Ncm, levadas ao polariscópio circular e submetidas a fotografias digitais padronizadas .Resultados: foi constatada a presença de tensões em ambos os grupos, contudo, a solda TIG exibiu maior número de franjas entre os implantes e nas cervicais distais. Conclusão: a estrutura confecciona por soldagem a Laser gerou menos tensões ao redor dos implantes que a confeccionada por soldagem a TIG para as infraestruturas de Co-Cr.
Aim: evaluate by using photoelasticity, the influence of laser welding or TIG welding of cylindrical rods of Cobalt-Chromium in the generation of tensions around implants. Methodology: using a working model with two screw implants, Cobalt-Chrome frameworks were made by laser welding method (Group 1) and TIG method(Group 2). Then, on a photoelastic model were bolted steel structures with manual torque of 20 Ncm, put to the circular polariscope and subjected to standardized digital photographs.Results: confirmed the presence of tensions in both groups, however, the TIG welding exhibited higher number of fringes between the implants and the distal neck. Conclusion: laser welding framework has generated less tension on the implants that the TIG welding for Cobalt-Chrome framework.
Assuntos
Parafusos Ósseos , Implantes Dentários , Lasers , Ligas de Cromo/química , Soldagem em Odontologia/métodos , Planejamento de Prótese Dentária , Análise do Estresse Dentário , Implantação Dentária/métodos , Teste de Materiais , Reprodutibilidade dos Testes , Fatores de Tempo , Tungstênio/químicaRESUMO
Reabilitações protéticas sobre implantes ainda é um desafio para Odontologia. Existem situações em que os implantes são colocados em locais não compatíveis com o posicionamento dos dentes no arco, sendo necessário utilizar compensações protéticas capazes de corrigir essa dificuldade. Este trabalho tem como objetivo, relatar um caso clínico que apresenta uma opção protética para compensar o mau posicionamento dos implantes, pelo uso de uma mesoestrutura metálica. O paciente apresentava uma deformação óssea na região anterior de maxila onde foram instalados quatro implantes, posicionados de tal forma que os acessos aos parafusos protéticos ocorriam em áreas estética e biomecanicamente desfavoráveis. Portanto, foi planejado a confecção de uma mesoestrutura metálica, alterando a região de acesso aos parafusos protéticos, o que proporcionou ótimo resultado estético e satisfação do paciente.
Prosthetic rehabilitation on implants is still a challenge for Dentistry. There are situations where the implants are placed in locations that are not compatible with the positioning of the teeth in the arch, prosthetic compensation is necessary to be able to fix this problem. This study aims, report a clinical case that presents a prosthetic option to compensate the poor positioning of implants, by using a metallic mesostructure.The patient had a bone deformation in the anterior maxilla where four implants were installed, positioned so that access to prosthetic screws occurred in areas aesthetics and biomechanically unfavorable. So it was planned the construction of a metallic mesostructure, changing the area of access to prosthetic screws, which provided excellent aesthetic results and patient satisfaction.
RESUMO
PURPOSE: This study evaluated the resistance to corrosion in welds made with Tungsten Inert Gas (TIG) in specimens made of commercially pure titanium (cp Ti) in comparison with laser welds. MATERIALS AND METHODS: A total of 15 circular specimens (10-mm diameter, 2-mm thick) were fabricated and divided into two groups: control group-cp Ti specimens (n = 5); experimental group-cp Ti specimens welded with TIG (n = 5) and with laser (n = 5). They were polished mechanically, washed with isopropyl alcohol, and dried with a drier. In the anodic potentiodynamic polarization assay, measurements were taken using a potentiostat/galvanostat in addition to CorrWare software for data acquisition and CorrView for data visualization and treatment. Three curves were made for each working electrode. Corrosion potential values were statistically analyzed by the Student's t-test. RESULTS: Statistical analysis showed that corrosion potentials and passive current densities of specimens welded with TIG are similar to those of the control group, and had lower values than laser welding. TIG welding provided higher resistance to corrosion than laser welding. CONCLUSION: Control specimens welded with TIG were more resistant to local corrosion initiation and propagation than those with laser welding, indicating a higher rate of formation and growth of passive film thickness on the surfaces of these alloys than on specimens welded with laser, making it more difficult for corrosion to occur.
Assuntos
Ligas Dentárias/química , Titânio , Soldagem/métodos , Corrosão , Técnicas Eletroquímicas , Lasers , Teste de Materiais , Gases Nobres , Óxidos , Saliva Artificial , Titânio/química , TungstênioRESUMO
A reabilitação total maxilar com próteses implantossuportadas representa em algumas situações clínicas dificuldades quanto a estética, fonética, suporte labial e higienização. As próteses destacáveis implantossuportadas são uma opção de tratamento frente a essa situação, onde o uso de encaixes permite a conexão entre uma prótese removível e uma infraestrutura metálica, sendo estéticos e funcionalmente eficientes. O objetivo deste trabalho foi de apresentar por meio de um caso clínico a confecção de uma protese destacável do sistema Swivel Loc como alternativa de aperfeiçoar a previsibilidade dessas reabilitações
The total rehabilitation of maxilla with supported implant prostheses represent in some clinical difficulties regarding aesthetics, phonetics, lip support and hygiene. The detachable implant supported dentures are a treatment option when faced with this situation, the use of attachments allows a connection between a removable prosthesis and a metallic infrastructure, being aesthetic and functionally efficient. The aim of this work was present through a clinical case the making of a detachable prosthesis with Swivel Loc system as an alternative to improve the predictability of these rehabilitations
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Estética Dentária , Encaixe de Precisão de Dentadura , Osseointegração , Prótese Dentária Fixada por Implante , Reabilitação Bucal , Retenção de Dentadura/métodos , Materiais DentáriosRESUMO
Widely used in dentistry, Ti-6Al-4V alloy is difficult to cast and solder, as it frequently exhibits pores inside the structure. This study was conducted to evaluate the effect of joint openings and diameters of laser-welded joints executed in Ti-6Al-4V structures on the presence of pores as checked by radiographic procedures. Sixty dumbbell rods with central diameters of 1.5, 2.0 and 3.5 mm were created from Ti-6Al-4V-wrought bars. Specimens were sectioned and welded using two joint openings (0.0 and 0.6 mm). The combination of variables created six groups (n = 10). Laser welding was executed using 360V/8ms (1.5 and 2.0 mm) and 380V/9ms (3.5 mm), with the focus and frequency set to zero. The joints were finished, polished and submitted to radiographic examination. The radiographs were visually examined for the presence of pores in the joints, qualitatively. The percentage of radiographic presence of pores was calculated without counting pores per joint. Data were analyzed using a chi-square test (α = 0.05). For the 1.5-mm specimens, the incidence of pore presence was significantly higher (p = 0.0001) when using 0.6-mm joint openings (40 percent) compared to 0.0-mm openings (0 percent). For the 2.0-mm specimens, there was no significant difference between groups (p = 0.2008). However, for the 3.5-mm specimens, the incidence of pore presence was lower (p = 0.0061) for 0.6-mm openings (50 percent) compared to 0.0-mm openings (70 percent). Therefore, laser welding of Ti-6Al-4V structures with thin diameters provides the best condition for the juxtaposition of the parts.