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The aim of the study was to quantify the micro-architectural changes of the jaw bone in response to ovariectomy, exposed or not to bisphosphonate treatment. A total of 47 Wistar rats were ovariectomized (OVX) or sham-operated (shOVX) and exposed to osteoporosis preventive treatment for eight weeks either with bisphosphonates (alendronate, ALN; group OVX-ALN) three days/week at a dose of 2 mg/kg or with saline solution (untreated control condition; group OVX). The bone morphometric parameters of the trabecular jaw bone were assessed using ex vivo micro-computed tomography. The regions of interest investigated in the maxilla were the inter-radicular septum of the second molar and the tuber. The regions quantified in the mandible included the three molar regions and the condyle. A one-way analysis of variance followed by pairwise comparison using Tukey's HSD and the Games-Howell test was conducted to explore significant differences between the groups. In the maxilla, OVX decreased the bone volume in the inter-radicular septum of the second molar. Bisphosphonate treatment was able to prevent this deterioration of the jaw bone. The other investigated maxillary regions were not affected by (un)treated ovariectomy. In the mandible, OVX had a significant negative impact on the jaw bone in the buccal region of the first molar and the inter-radicular region of the third molar. Treatment with ALN was able to prevent this jaw bone loss. At the condyle site, OVX significantly deteriorated the trabecular connectivity and shape, whereas preventive bisphosphonate treatment showed a positive effect on this trabecular bone region. No significant results between the groups were observed for the remaining regions of interest. In summary, our results showed that the effects of ovariectomy-induced osteoporosis are manifested at selected jaw bone regions and that bisphosphonate treatment is capable to prevent these oral bone changes.
Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Difosfonatos/uso terapêutico , Mandíbula/ultraestrutura , Maxila/ultraestrutura , Osteoporose Pós-Menopausa/tratamento farmacológico , Animais , Osso Esponjoso/ultraestrutura , Feminino , Humanos , Ratos , Ratos WistarRESUMO
A new consumer profile for pharmaceutical and cosmetic products has motivated research into natural raw materials in the development of "green" products such as herbal medicines and biocosmetics. However, various limitations have been encountered in the marketing of these products, for example the quality control of the natural raw materials used by the industrial market. This study aims to evaluate the sensory and physicochemical parameters of murumuru (Astrocaryum murumuru Mart.), bacuri (Platonia insignis Mart.), tucuma (Astrocaryum vulgare Mart.), and ucuuba (Virola sebifera Aubl.) butters for applications in pharmaceutical and cosmetic bioproducts. The acidity and saponification as well as the iodine and peroxide indexes were evaluated and fatty acid profiles for the samples obtained by GC-MS. The sensory properties of the butters showed the appearance of solid to soft cream, color (yellow, brown, buttercup, and ochre), and characteristic odor. The melting temperatures of all butters ranged between 31 ºC and 49 °C. The acidity, saponification, iodine and peroxide indexes for the butters were of 5.82 17.73 mg (NaOH or KOH) g−1, 181.10 573.55 mg KOH g−1, 2.78 44.96 gl2 100 g−1, and 1.39 9.30 meq kg−1, respectively. From analyses of the fatty acid profiles, the major components identified were lauric acid in murumuru (40%) and ucuuba butters (73%), myristic acid in tucuma butter (53%), and palmitic acid in bacuri butter (42%). In general, the results of the analyses differed from the specifications of the supplier reports and official compendia. These findings highlight the importance of quality control in natural raw materials to ensure their functionality in pharmaceutical and cosmetic bioproducts.
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Micro-computed tomography can be applied for the assessment of the micro-architectural characteristics of the cortical and trabecular bones in either physiological or disease conditions. However, reports often lack a detailed description of the methodological steps used to analyse these images, such as the volumes of interest, the algorithms used for image filtration, the approach used for image segmentation, and the bone parameters quantified, thereby making it difficult to compare or reproduce the studies. This study addresses this critical need and aims to provide standardized assessment and consistent parameter reporting related to quantitative jawbone image analysis. Various regions of the rat jawbones were screened for their potential for standardized micro-computed tomography analysis. Furthermore, the volumes of interest that were anticipated to be most susceptible to bone structural changes in response to experimental interventions were defined. In the mandible, two volumes of interest were selected, namely, the condyle and the trabecular bone surrounding the three molars. In the maxilla, the maxillary tuberosity region and the inter-radicular septum of the second molar were considered as volumes of interest. The presented protocol provides a standardized and reproducible methodology for the analysis of relevant jawbone volumes of interest and is intended to ensure global, accurate, and consistent reporting of its morphometry. Furthermore, the proposed methodology has potential, as a variety of rodent animal models would benefit from its implementation.
Assuntos
Algoritmos , Mandíbula/diagnóstico por imagem , Mandíbula/ultraestrutura , Maxila/diagnóstico por imagem , Maxila/ultraestrutura , Microtomografia por Raio-X/métodos , Animais , Feminino , Técnicas In Vitro , Ratos , Ratos WistarRESUMO
Objective: The aim of this study was to assess the stresses and strains generated after the application of two types of forces (traction of 200 gf and torsion of 20 N.cm) in two types of orthodontic mini-implants inserted at different (45° and 90° to the cortical bone) angles. Material and method: three-dimensional models of two brands of mini-implant (SIN - Sao Paulo, Brazil, and RMO - South Korea) were exported and analyzed by finite element analysis (FEA). Analyses were performed on simulations of cortical bone, cancellous bone and the screw. Result: FEA analysis showed that RMO mini-implants had greater elastic deformation when subjected to tensile and torsional forces when compared with SIN mini-implants. For both trademarks and insertion angles tested, there was greater cortical bone deformation, but with the greatest strain located on the mini-implant. Tension on the mini-implant was located in its transmucosal profile region. Conclusion: When comparing the two brands of mini-implants by FEA, it is fair to conclude that that the larger number of threads and their greater angle of inclination resulted in less resistance to deformation and induced a higher level of tension in the mini-implant and cortical bone when subjected to forces, especially when inserted at an angle of 45º to the cortical bone.
Objetivo: O objetivo deste estudo foi avaliar as tensões e deformações de duas marcas comerciais de mini-implantes ortodônticos geradas após a aplicação de dois tipos de forças (de tração de 200 gf e torção de 20 N.cm) inseridos em duas angulações (45° e 90° em relação ao osso cortical). Material e método: Modelos tridimensionais das duas marcas de mini-implantes (SIN - Sao Paulo, Brasil, e RMO - Coréia do Sul) foram construídos e analisados por análise de elementos finitos (FEA). As análises foram realizadas em simulações no osso cortical, osso esponjoso e no parafuso. Resultado: A análise FEA mostrou que os mini-implantes da marca RMO apresentaram maior deformação elástica quando submetidos à tração e as forças de torção quando comparado aos mini-implantes da marca SIN. Em ambas as marcas testadas, e para os diferentes ângulos de inserção, houve uma maior deformação do osso cortical, com maior tensão localizado no mini-implante. A tensão no mini-implante foi localizado na região do perfil transmucoso. Conclusão: Ao comparar as análises de elementos finitos das duas marcas comerciais de mini-implantes, concluiu-se que um maior número de roscas e maior inclinação resultam em menor resistência à deformação e induzem uma maior tensão no osso cortical quando submetidos à forças de torção e tração, especialmente quando inserido em um ângulo de 45º com o osso cortical.
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Ortodontia , Análise de Elementos Finitos , Procedimentos de Ancoragem OrtodônticaRESUMO
Introduction and Objective: Photoelasticity consists of an experimental technique of stress analysis. This technique is very used in most different areas including Dentistry. This literature review presents the several applications of photoelastic technique in Dentistry as well as its advantages and disadvantages. Literature review: Based on this method of analysis, it is possible the verification of the stress distribution and deformation in structures with complex geometry as maxilla and mandible. It can be used to evaluate the distribution of stress on several types of prosthesis as removable partial denture systems with different retention systems, conventional implant prosthesis, overdentures and Brånemark protocols. Moreover, photoelasticity can be used to assess the stress generated by various orthodontic movements, different orthodontic systems and different materials (orthodontic wires). In addition, it is used to analyze different defects of maxillectomy, splint types on traumatized tooth and post-core restoration methods. This technique can also be used to assess dental instruments such as evaluation of different designs of periodontal probe. Conclusion: The photoelastic analysis has been a technique of great importance in health area studies, more specifically in Dentistry. Based on this method of analysis, it is possible to measure the stress distribution and deformation in structures with complex geometry as maxilla and mandible.
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Introdução : O adequado posicionamento tridimensional dos implantes é indispensável para garantir a previsibilidade no tratamento com implantes dentários. Objetivo : Analisar comparativamente o comportamento mecânico do sistema prótese/implante em região anterior de maxila, diferindo os sistemas de encaixe e posicionamento dos implantes. Material e Método : Utilizando um modelo prototipado de maxila, as situações estudadas foram: Grupo IC - implantes nos incisivos centrais e cantilever nos incisivos laterais; Grupo IL - implantes nos incisivos laterais e pônticos nos incisivos centrais; Grupo ICIL - implantes no incisivo central e no incisivo lateral, intercalados com elementos suspensos. Para cada situação estudada, foram utilizadas as três conexões protéticas: hexágono externo, hexágono interno e cone-Morse. O ensaio de ciclagem mecânica foi realizado com a aplicação de 100 N de carga e frequência de 15 Hz no cíngulo dos incisivos a 45° com o longo eixo do dente, para simular o movimento mastigatório. Resultado : No ensaio de ciclagem mecânica, todos os modelos de todos os grupos com os três tipos de conexões protéticas atingiram um milhão de ciclos sem que ocorresse ruptura do parafuso, do componente protético ou da estrutura metálica. Conclusão : Com a metodologia e as condições empregadas, pode-se concluir que o comportamento mecânico das reabilitações implantossuportadas foi semelhante para os diferentes posicionamentos dos implantes e diferentes conexões protéticas. .
Introduction: The adequate three-dimensional positioning of implants is essential to ensure predictability in dental implant treatment. Purpose : Was to comparatively evaluate the mechanical behavior of the system prosthesis/implant in the anterior maxilla, differing the prosthetic connection and the placement of implants. Material and Method: By a maxilla prototyped model the situations were studied: Group IC- implants in the central incisor positions and cantilevers in the lateral incisor positions; Group IL - implants in the lateral incisor positions and pontics in the central incisor positions; Group ICIL one implant in a lateral and one in a central incisor position, with a pontic and a cantilever in the other positions. For each situations were used the prosthetic connections, external hexagon, internal hexagon and Morse-taper. In fatigue test was applied load 100N of frequency 15Hz in the incisors cingulum 45° to the long axis of the tooth to simulate a masticatory movement. Result: After the fatigue test all models of all groups with all three types of connections prosthetic reached 1 million cycles without rupture occurred screw, prosthetic component or metallic structure. Conclusion: According to methodology and conditions studied, can be concluded that the mechanical behavior of the implant-supported rehabilitation was similar to the different positions of the dental implants and the different prosthetic connections. .
Assuntos
Estresse Mecânico , Prótese Dentária Fixada por Implante , Implantação Dentária , Maxila , Reabilitação BucalRESUMO
STATEMENT OF PROBLEM: In dental rehabilitations that involve implants, the number of implants is sometimes smaller than the number of lost teeth. This fact can affect the biomechanical behavior and success of the implants. PURPOSE: The purpose of this study was to investigate the mechanical behavior of different implant positions in the rehabilitation of the anterior maxilla. MATERIAL AND METHODS: Three-dimensional models of the maxilla were created based on computed tomography images for 3 different anterior prosthetic rehabilitations. In group IL, the implants were placed in the lateral incisor positions with pontics in the central incisor positions; in group IC, the implants were in the central incisor positions with cantilevers in the lateral incisor positions; and, in group ILIC, one implant was in a lateral incisor position and one was in a central incisor position, with a pontic and a cantilever in the remaining positions. A 150 N load was distributed and applied at the center of the palatal surface of each tooth at a 45-degree angle to the long axis of the tooth. The resulting stress-strain distribution was analyzed for each group. RESULTS: The lowest displacement of the prosthetic structure was observed in group IC, although the same group exhibited the largest displacement of the bone tissue. In the bone tissue, the von Mises stress was mainly observed in the cortical bone in all groups. The maximum value of the von Mises stress shown in the cortical tissue was 35 MPa in the implant that neighbors the cantilever in group ILIC. The maximum von Mises stress in the trabecular bone was 3.5 MPa. CONCLUSION: The prosthetic configuration of group IC limited the displacement of the prosthetic structure but led to greater displacement of the bone structure. The use of a cantilever increased the stress concentration in the implant and in the bone structure adjacent to the cantilever under the conditions studied here.
Assuntos
Arco Dental/patologia , Implantes Dentários , Arcada Parcialmente Edêntula/reabilitação , Maxila/patologia , Fenômenos Biomecânicos , Ligas de Cromo/química , Simulação por Computador , Dente Suporte , Materiais Dentários/química , Prótese Dentária Fixada por Implante , Planejamento de Dentadura , Prótese Parcial , Módulo de Elasticidade , Análise de Elementos Finitos , Humanos , Imageamento Tridimensional/métodos , Incisivo , Modelos Biológicos , Estresse Mecânico , Propriedades de Superfície , Titânio/química , Tomografia Computadorizada por Raios X/métodosRESUMO
A proposta deste estudo foi analisar, por meio do método de elementos finitos (MEF), o comportamento mecânico das estruturas envolvidas em uma reabilitação implanto suportada de 4 elementos na região anterior de maxila, utilizando apenas 2 implantes, variando os posicionamentos dos implantes e o tipo de conexão protética (hexágono externo, hexágono interno e cone-Morse) e ainda validar metodologia de análise computacional por meio da interferometria holográfica, uma técnica experimental. Modelos tridimensionais baseados em um banco de tomografias computadorizadas foram criados para todas as situações estudadas (Implantes nos Incisivos Laterais - IL; Implantes nos Incisivos Centrais - IC e Implante no Incisivo Central e Incisivo Lateral - ILIC). Uma carga equivalente à 150N foi aplicada a 45° na região de cíngulo de cada elemento dentário. Para a validação da metodologia de elementos finitos por meio da interferometria holográfica, criou-se um modelo prototipado com as mesmas situações estudadas e comparou-se os deslocamentos direcionais resultantes da aplicação de 3 intensidades de força. Como resultado foi observado: o menor deslocamento da estrutura protética e maior deslocamento na estrutura óssea no grupo IC. No tecido ósseo, a tensão de von Misses localiza-se predominantemente na região cortical. O valor máximo de tensão de von Misses foi observado no implante vizinho ao cantilever no grupo ILIC. Na conexão cone Morse, o parafuso protético mostrou metade da tensão de von Misses em relação a conexão hexágono interno e hexágono externo. Comparando-se os deslocamentos direcionais nas duas metodologias, verificou-se que havia uma correlação positiva entre os resultados, porém os valores obtidos experimentalmente eram superiores aos do modelo computacional. Pode-se concluir...
The purpose of this study was to analyze, by finite element method (FEM), the mechanical behavior of structures involved in an implant supported rehabilitation of 4 elements in the anterior maxilla, using only 2 implants, varying the placements of the implants and prosthetic connection types (external hexagon, internal hexagon and Morse taper) Moreover to validate the methodology of MEF by holographic interferometry, an experimental technique. Three-dimensional models based on a database CT scans were created for all situations studied (Implants in Lateral Incisors - IL; Implants in Central Incisors IC and Implant in Central e Lateral Incisor - ILIC). An equivalent load of150N was applied at 45° in the cingulum of each tooth. To validate the finite element method by Holographic Interferometry, a prototyped model was created with the same situations studied and compared the directional displacements, resulting from the application of the 3 intensities of force. As results it was observed: the lowest prosthetic displacement structure and greater displacement in the bone structure in the IC group. In bone tissue, the von Mises stress is located predominantly in the cortical region. The maximum value of von Mises stress was observed in the implant neighboring to cantilever in the group ILIC. In Morse taper connection, the prosthetic screw showed half the von Misses stress in relation to internal and external hexagon connection. Comparing the directional displacement in both methodologies, an positive correlation between the results was found, although the experimentally values obtained were higher than those of the computational model. It can be concluded that the placement of implants and prosthetic connection type have influence in the intensity and distribution of stress/strain on the implant-supported rehabilitation of anterior...
Assuntos
Humanos , Implantes Dentários , Prótese Dentária Fixada por Implante , Interferometria , Análise Numérica Assistida por ComputadorRESUMO
A proposta deste estudo foi analisar, por meio do método de elementos finitos (MEF), o comportamento mecânico das estruturas envolvidas em uma reabilitação implanto suportada de 4 elementos na região anterior de maxila, utilizando apenas 2 implantes, variando os posicionamentos dos implantes e o tipo de conexão protética (hexágono externo, hexágono interno e cone-Morse) e ainda validar metodologia de análise computacional por meio da interferometria holográfica, uma técnica experimental. Modelos tridimensionais baseados em um banco de tomografias computadorizadas foram criados para todas as situações estudadas (Implantes nos Incisivos Laterais - IL; Implantes nos Incisivos Centrais - IC e Implante no Incisivo Central e Incisivo Lateral - ILIC). Uma carga equivalente à 150N foi aplicada a 45° na região de cíngulo de cada elemento dentário. Para a validação da metodologia de elementos finitos por meio da interferometria holográfica, criou-se um modelo prototipado com as mesmas situações estudadas e comparou-se os deslocamentos direcionais resultantes da aplicação de 3 intensidades de força. Como resultado foi observado: o menor deslocamento da estrutura protética e maior deslocamento na estrutura óssea no grupo IC. No tecido ósseo, a tensão de von Misses localiza-se predominantemente na região cortical. O valor máximo de tensão de von Misses foi observado no implante vizinho ao cantilever no grupo ILIC. Na conexão cone Morse, o parafuso protético mostrou metade da tensão de von Misses em relação a conexão hexágono interno e hexágono externo. Comparando-se os deslocamentos direcionais nas duas metodologias, verificou-se que havia uma correlação positiva entre os resultados, porém os valores obtidos experimentalmente eram superiores aos do modelo computacional. Pode-se concluir que o posicionamento dos implantes e o tipo de conexão protética em reabilitação anterior de maxila influenciam a distribuição e intensidade de tensão/deformação nas estruturas da prótese implanto-suportada e ainda que o MEF pode ser usado como uma eficiente técnica para a análise de tensão, deformação e deslocamento quando utilizada com modelos validados experimentalmente
The purpose of this study was to analyze, by finite element method (FEM), the mechanical behavior of structures involved in an implant supported rehabilitation of 4 elements in the anterior maxilla, using only 2 implants, varying the placements of the implants and prosthetic connection types (external hexagon, internal hexagon and Morse taper) Moreover to validate the methodology of MEF by holographic interferometry, an experimental technique. Three-dimensional models based on a database CT scans were created for all situations studied (Implants in Lateral Incisors - IL; Implants in Central Incisors IC and Implant in Central e Lateral Incisor - ILIC). An equivalent load of150N was applied at 45° in the cingulum of each tooth. To validate the finite element method by Holographic Interferometry, a prototyped model was created with the same situations studied and compared the directional displacements, resulting from the application of the 3 intensities of force. As results it was observed: the lowest prosthetic displacement structure and greater displacement in the bone structure in the IC group. In bone tissue, the von Mises stress is located predominantly in the cortical region. The maximum value of von Mises stress was observed in the implant neighboring to cantilever in the group ILIC. In Morse taper connection, the prosthetic screw showed half the von Misses stress in relation to internal and external hexagon connection. Comparing the directional displacement in both methodologies, an positive correlation between the results was found, although the experimentally values obtained were higher than those of the computational model. It can be concluded that the placement of implants and prosthetic connection type have influence in the intensity and distribution of stress/strain on the implant-supported rehabilitation of anterior maxilla and moreover the FEM can be used as an efficient technique for analysis of stress, strain and displacement when used with experimentally validated models
Assuntos
Fenômenos Biomecânicos , Análise de Elementos Finitos , Maxila , Implantes Dentários , Interferometria , Prótese Dentária Fixada por ImplanteRESUMO
Para reabilitação bucal de elementos dentários perdidos, cada vez mais tem se utilizado a reabilitação implantossuportada. Porém, o paciente pode apresentar condições que limitam a condição ideal para o adequado posicionamento tridimensional dos implantes. Algumas dessas condições são a quantidade, a qualidade e o volume ósseo em rebordo maxilar anterior. O enxerto ósseo autógeno é, atualmente, a melhor opção para reconstrução óssea em espessura na região anterior de maxila. Este artigo descreve a reabilitação de um caso clínico de ausência dos incisivos maxilares, cujo tratamento consistiu de reconstrução em espessura com enxerto ósseo autógeno, instalação de dois implantes e reabilitação final implantossuportada
Oral rehabilitation of teeth lost, has been increasingly used the implant-supported rehabilitation. However, the patient may present with conditions that limit an appropriate three-dimensional positioning of the implants. Some of these conditions are quantity, quality and bone volume in the anterior maxillary ridge. The autogenous bone graft is currently the best choice to fill thickness in the anterior maxilla. This article describes the rehabilitation of a clinical case of absence of maxillary incisors, whose treatment consisted on reconstruction with autogenous bone graft in thickness, installation of two implants and implant-supported final rehabilitation
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Humanos , Feminino , Implantes Dentários , Maxila/cirurgia , Prótese Dentária Fixada por Implante/métodos , Transplante Autólogo/métodos , Transplante Autólogo , Radiografia Panorâmica/métodos , Radiografia PanorâmicaRESUMO
O trabalho investigou a influência do uso do extrato de levedura, fonte dos mediadores redox riboflavina e nicotinamida, na remoção de cor de solução de corante azo Drimaren Azul HF-RL em condições anaeróbias. O trabalho envolveu a execução de ensaios em batelada, em frascos-reatores mantidos a 25 ºC, incubados com o azo-corante e lodo anaeróbio na presença e ausência de fontes de carbono (extrato de levedura ou glicose) e de mediadores redox (riboflavina ou extrato de levedura). O monitoramento da variação temporal de cor, a demanda química de oxigênio (DQO) e ácidos graxos voláteis (AGV) mostraram que a adição de extrato de levedura (0,5 g/L) resultou em eficiências de remoção de cor de 80 a 85 por cento nas primeiras 24 horas de incubação, e que os produtos da degradação do azo-corante foram tóxicos para todo o consórcio anaeróbio, o que resultou em baixas eficiências de remoção de DQO na presença e ausência do extrato de levedura. Os resultados indicaram, ainda, que as eficiências de remoção de cor foram inferiores a 30 por cento na presença de apenas glicose (fonte de carbono) ou riboflavina (mediador redox), indicando que o extrato de levedura atuou simultaneamente como fonte de carbono e de mediadores redox.
This paper investigated the influence of using yeast extract, which is the source of redox mediators riboflavin and nicotinamide, in the decolorization of solutions containing the azo dye Drimaren Blue HF-RL in anaerobic conditions. It involved the incubation of serum bottles kept at 25 ºC and inoculated with the azo-dye, and anaerobic sludge in the presence and absence of carbon source (glucose or yeast extract) and redox mediators (riboflavin and yeast extract). The monitoring of color, chemical oxygen demand (COD) and volatile fatty acids (VFA) showed that the addition of yeast extract (0.5 g/L) resulted in 80 to 85 percent color removal in the first 24 hours of incubation; and that the metabolites of dye degradation were toxic to the anaerobic microorganisms, which led to low COD removal efficiencies either in the presence or absence of yeast extract. The results also showed that the efficiencies of color removal were below 30 percent in the presence of only glucose or riboflavin, indicating that the yeast extract acted simultaneously as source of carbon and redox mediators.
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PURPOSE: The influence of fatigue and the fluoride ion corrosion process on Streptococcus mutans adherence to commercially pure Titanium (Cp Ti) implant/component set surfaces were studied. MATERIALS AND METHODS: Thirty Nobel implants and 30 Neodent implants were used. Each commercial brand was divided into three groups. Group A: control, Group B: sets submitted to fatigue (10(5) cycles, 15 Hz, 150 N), and Group C: sets submitted to fluoride (1500 ppm, pH 5.5) and fatigue, simulating a mean use of 5 years in the oral medium. Afterward, the sets were contaminated with standard strains of S. mutans (NTCC 1023) and analyzed by scanning electronic microscopy (SEM) and colony-forming unit counts (CFU/mL). RESULTS: By SEM, bacterial adherence was verified only in group C in both brands. By CFU/mL counts, S. mutans was statistically higher in both brands in group C than in groups A and B (p < 0.05, ANOVA). CONCLUSION: The process of corrosion by fluoride ions on Cp Ti implant/component sets allowed greater S. mutans adherence than in the absence of corrosion and with the fatigue process in isolation.
Assuntos
Aderência Bacteriana , Implantes Dentários/microbiologia , Fluoretos/química , Titânio/química , Análise de Variância , Cariostáticos/química , Corrosão , Materiais Dentários/química , Análise do Estresse Dentário , Eletroquímica , Contaminação de Equipamentos , Teste de Materiais , Streptococcus mutans , Estresse Mecânico , Propriedades de SuperfícieRESUMO
PURPOSE: The objective of this study was to assess the influence of a fluoride medium with different pHs on the corrosion resistance of three commercially pure titanium-based dental implant commercial brands, under scanning electron microscopy (SEM) and EDS. MATERIALS AND METHODS: Forty-two dental implants, from three commercial brands, were used. Five years of regular use of mouth rinsing, with NaF 1500 ppm content and two different pHs, were simulated by immersing the specimens into that medium for 184 hours. RESULTS: SEM and EDS analyses demonstrated no evidence of corrosion on the specimens' surfaces after being submitted to fluoride ions or incorporation of fluoride ions to the set surface. CONCLUSION: It was possible to conclude that both the fluoride concentration and the pH of the solutions did not exert any influence upon implant corrosion resistance.
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Cariostáticos/química , Implantes Dentários , Materiais Dentários/química , Fluoretos/química , Titânio/química , Corrosão , Planejamento de Prótese Dentária , Microanálise por Sonda Eletrônica , Humanos , Concentração de Íons de Hidrogênio , Imersão , Teste de Materiais , Microscopia Eletrônica de Varredura , Antissépticos Bucais/química , Propriedades de Superfície , Fatores de TempoRESUMO
O estudo da adesão e colonização bacteriana sobre o titânio é de grande importância, pois são fatores principais na patogenia de infecções em biomateriais. A adesão e colonização bacteriana podem variar de acordo com o biomaterial, tipo de microrganismo, fase de crescimento e propriedades superficiais dos materiais. A rugosidade de superfícies sólidas intraorais também tem uma influência na adesão bacteriana. Regiões com uma alta rugosidade de superfícies acumulam e retém mais placa bacteriana. A rugosidade de implantes dentais à base de Ti c.p. pode ser alterada por meio de corrosão por fluoretos.