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This study aimed to evaluate two methods of the incorporation of nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) into acrylic resin and characterize the profile of early and late microbial communities in class and family taxonomic level by pyrosequencing. The specimens were made by adding different concentrations of AgVO3 (1, 2.5, and 5%) to the heat-activated acrylic resin by two methods: vacuum spatulation (VS) and polymeric film (PF). A control group (0%) without AgVO3 was also obtained for both methods. After 24 h and 7 days of incubation in human saliva, biofilm samples were collected, DNA was extracted, and 16S rRNA genes were sequenced by the 454-Roche sequencing platform. Seventeen classes and 51 families of bacteria were identified. The abundance of Bacteroidia, Bacilli, Negativicutes, Fusobacteria and Betaproteobacteria classes decreased after 7 days of incubation, and Clostridia, Gammaproteobacteria, and unclassified bacteria increased. The Negativicutes and Betaproteobacteria classes were more abundant when the PF method was used, and Gammaproteobacteria was more abundant when VS was used. The incorporation of 5% AgVO3 promoted a reduction in the prevalence of Bacilli, Clostridia, Negativicutes, Betaproteobacteria, and unclassified bacteria, and increased Gammaproteobacteria. The addition of AgVO3 to acrylic resin altered the early and mature microbiome formed on the specimen surface, and the PF method presented a more favorable microbial profile than the VS method.
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Nanopartículas del Metal , Microbiota , Nanoestructuras , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Polímeros , ARN Ribosómico 16S/genética , Plata , Compuestos de Plata , Vanadatos , VanadioRESUMEN
PURPOSE: To investigate the physical and mechanical behaviors of polyether ether ketone (PEEK) before and after thermocycling, as well as its potential use as a more durable prosthetic component for implant-supported and -retained removable dental prostheses (I-RDPs). MATERIALS AND METHODS: Roughness and surface hardness were evaluated in specimens obtained using the subtractive method (n = 20) with a diameter of 9 mm and a thickness of 2 mm, and retention force was measured using attachments with a diameter of 4 mm and a height of 3 mm. For fatigue resistance testing, a polyurethane matrix with two ball abutment implants (MDL, Intra-Lock International) was used to simulate the mandibular alveolar ridge. A total of 40 attachments (n = 20 pairs) were placed in acrylic resin blocks using an analog technique for the direct clinical pickup of overdenture female attachments, then submitted to 2,900 insertion/removal cycles to simulate 24 months of overdenture use. Physical analyses were performed by Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and differential scanning calorimetry (DSC) before and after thermocycling (5°C to 55°C for 10,000 cycles). After normal distribution was verified by Shapiro-Wilk test, one-way ANOVA was applied to analyze the surface roughness and hardness, and two-way ANOVA with Bonferroni adjustment was used to assess the retention force (α = .05). RESULTS: Thermocycling did not change the PEEK surface roughness or hardness (P > .05). As for the retention force, the highest average was observed after the thermocycling test (P = .006). CONCLUSION: Based on the FTIR, XRD, and DSC results, PEEK crystallinity decreased after thermocycling, and the physical and mechanical behaviors of this polymer were compatible with the proposed application, suggesting that PEEK is a component of greater durability for I-RDPs. Int J Prosthodont 2023;36:612-619.
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Implantes Dentales , Diente , Femenino , Humanos , Resinas Acrílicas/química , Prótesis de Recubrimiento , Polietilenglicoles , Prótesis Dental de Soporte Implantado , Análisis del Estrés Dental , Retención de Dentadura/métodosRESUMEN
Resumo Introdução Após o advento dos termoplásticos de baixa temperatura, sua prevalência na confecção de órteses para membros superiores é identificada por vários autores. A compreensão de suas propriedades, por parte do terapeuta ocupacional e de outros profissionais que atuam na área, é importante no processo de seleção do termoplástico, que segue uma lógica para combinar as características do material à função desejável para cada órtese. Objetivos Sistematizar as características dos termoplásticos de baixa temperatura e, a partir disso, elaborar um instrumento para realizar testes práticos empíricos com os materiais a fim de estabelecer critérios para o seu manuseio e avaliação. Método Pesquisa de caráter exploratório, constituindo a criação de procedimentos de teste e, consequentemente, a elaboração de um instrumento de avaliação de abordagem qualitativa e que valoriza a experiência prática do profissional, que manipula o material e avalia cada requisito. Resultados O instrumento criado contempla 14 caraterísticas do material, acompanhadas de uma definição, um procedimento com recomendações para o teste prático e um campo destinado ao preenchimento das alternativas de resposta. Conclusão O instrumento considera características importantes a serem verificadas durante a avaliação dos materiais e poderá direcionar o olhar e os registros do profissional, auxiliando o nas decisões clínicas. Isso será importante para melhorar a qualidade das órteses e de outros dispositivos de Tecnologia Assistiva confeccionados com esse grupo de materiais. Além disso, a sistematização da avaliação prática dos materiais termoplásticos poderá auxiliar no desenvolvimento de estudos da área da saúde e de pesquisas envolvendo materiais para órteses.
Abstract Introduction After the advent of low-temperature thermoplastics, their prevalence in the manufacture of orthoses for upper limbs has been identified by several authors. The understanding of their properties by occupational therapists and other professionals working in this field is important in the process of selecting the thermoplastic, which follows a logic to match the material's characteristics to the desired function for each orthosis. Objectives Systematize the characteristics of low-temperature thermoplastics and, from that, develop an instrument for carrying out practical empirical tests with the materials, to establish criteria for their handling and evaluation. Method Exploratory study consisting of the creation of testing procedures and, consequently, the development of a qualitative assessment instrument that values the practical experience of the professional who handles the material and evaluates each requirement. Results The created instrument includes 14 material characteristics, accompanied by a definition, a procedure with recommendations for the practical testing, and a field for filling in response alternatives. Conclusions The instrument considers important characteristics to be verified during the evaluation of materials and can direct the professional's observations and records, aiding in clinical decision-making. This will be important to improve the quality of orthoses and other assistive technology devices made with these thermoplastics. In addition, the systematization of the practical evaluation of thermoplastic materials can assist in the development of health studies and research involving materials for orthoses.
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OBJECTIVES: This study characterized the microbial diversity of formed biofilm on the surface of acrylic resins modified with nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) after incubation in human saliva. DESIGN: Resin specimens prepared with AgVO3 at concentrations 0%, 1%, 2.5%, and 5% by either vacuum mixing or polymer solubilization were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). After 24â¯h and 7 days of saliva incubation, biofilm samples were collected from the surface of the specimens. The 16S rDNA genes were amplified, sequenced with the 454-Roche next-generation sequencing platform and analyzed to identify the Operational Taxonomic Units at the genus or higher level. RESULTS: Significant differences in the dispersion pattern of the nanoparticles were observed among the two different methods of AgVO3 incorporation. In the microbiological analysis, a total of 103 genera and 7 more inclusive taxa, representing the phyla Bacteroidetes, Firmicutes and Proteobacteria were identified colonizing resin surfaces. The incorporation method of the AgVO3 had little to no significant effect on the microbiota of samples. Significant time and concentration-dependent responses to AgVO3 caused changes in the taxonomic profile at the phylum and genus level. CONCLUSIONS: The results show differences in relation to the microbial diversity of modified resins during the initial phase of biofilm maturation. The incorporation of AgVO3 seems to significantly affect the colonizing microbiota.
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Resinas Acrílicas/química , Biopelículas/efectos de los fármacos , Materiales Dentales/química , Nanopartículas del Metal/química , Microbiota , Plata/química , Vanadatos/química , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Técnicas In Vitro , Masculino , Ensayo de Materiales , Microscopía Electrónica , Persona de Mediana Edad , Polímeros/química , Propiedades de SuperficieRESUMEN
The objectives of this study were to evaluate physical properties and antibacterial activity of a light-activated composite modified with silver nanoparticles. Discs were produced with unmodified resin (control group - CG) and modified resin with silver nanoparticles at two concentrations, 0.3% wt (MR03) and 0.6% wt (MR06). Streptococcus mutans and Lactobacillus acidophilus biofilms were induced in vitro by incubation of discs in a 20% sucrose medium, followed by sonication and counting of viable cells after 1, 4 and 7 days (n=9). The arithmetic roughness of all three groups was evaluated by atomic force microscopy (n=9). Compression assay was conducted in all groups to measure the compressive strength at failure and elasticity modulus (n=5). Data were subjected to ANOVA and Tukey's tests (α=0.05%). At all three time points the number of viable cells was statistically lower for MR03 and MR06 compared with CG, for both specimens. MR03 and MR06 showed no significant differences. Microscopic analysis demonstrated no significant differences for roughness among the three groups (p>0.05). The MR03 was stronger to compression than CG, and MR06 was statistically lower than CG and MR03. It was concluded that the MR03 were less conducive to biofilm growth, without compromising the strength in compression and surface roughness.
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Resinas Compuestas , Nanopartículas del Metal/química , Plata/química , Técnicas In Vitro , Lactobacillus acidophilus/efectos de los fármacos , Plata/farmacología , Streptococcus mutans/efectos de los fármacos , Propiedades de SuperficieRESUMEN
AIM: The aim of this study was to evaluate the influence of accelerated artificial aging (AAA) on the color change of composite resins used in dentistry. MATERIALS AND METHODS: Three composite resins were evaluated: Two microhybrids and one hybrid of higher viscosity, with different amounts and sizes of filler particles, shades C2 and B2. A total of 54 specimens were obtained (18 for each composite resin), made of a Teflon matrix (15 mm in diameter and 2 mm in height). The color measurements were obtained with a Spectrophotometer, (PCB 6807 BYK Gardner) before and after AAA. Data were submitted to the Kolmogorov-Smirnov test (α >0.05), ANOVA and Tukey test (α <0.05). After statistical analysis, the color difference among composite resins with the same shades was analyzed. RESULTS: All composite resins showed unacceptable color changes after AAA (ΔE > 3). Considering the variable ∆E, it was observed that the color tone C2 was already statistically different for the microhybrid composite resin prior to AAA (P < 0.05) and in shade B2 for hybrid of higher viscosity and microhybrid with barium glass fluoride aluminum and silica dioxide (P < 0.01). After this process, a statistically significant difference was observed only for shade B2 between microhybrid composite resins (P < 0.01) and for hybrid of higher viscosity and microhybrid with barium glass fluoride aluminum and silica dioxide (P < 0.05). Regarding the color difference within a same composite resin group, before aging the composite resin hybrid of higher viscosity B2 showed the highest color variation rate and microhybrid with zirconium/silica C2 showed the lowest. CONCLUSIONS: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2) and after (B2). It was also observed color difference within a group of the same composite resin and same hue.
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Color , Resinas Compuestas , Materiales Dentales , Análisis de Varianza , ColorimetríaRESUMEN
The aim of this study was to investigate the influence of accelerated artificial aging (AAA) on the microstructure and mechanical properties of the Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma and Filtek Z100. composite resins. The composites were characterized by Fourier-transform Infrared spectroscopy (FTIR) and thermal analyses (Differential Scanning Calorimetry - DSC and Thermogravimetry - TG). The microstructure of the materials was examined by scanning electron microscopy. Surface hardness and compressive strength data of the resins were recorded and the mean values were analyzed statistically by ANOVA and Tukey's test (α=0.05). The results showed significant differences among the commercial brands for surface hardness (F=86.74, p<0.0001) and compressive strength (F=40.31, p<0.0001), but AAA did not affect the properties (surface hardness: F=0.39, p=0.53; compressive strength: F=2.82, p=0.09) of any of the composite resins. FTIR, DSC and TG analyses showed that resin polymerization was complete, and there were no differences between the spectra and thermal curve profiles of the materials obtained before and after AAA. TG confirmed the absence of volatile compounds and evidenced good thermal stability up to 200 °C, and similar amounts of residues were found in all resins evaluated before and after AAA. The AAA treatment did not significantly affect resin surface. Therefore, regardless of the resin brand, AAA did not influence the microstructure or the mechanical properties.
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Resinas Compuestas/química , Fuerza Compresiva , Análisis del Estrés Dental , Dureza , Técnicas In Vitro , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Polimerizacion , Dióxido de Silicio/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Termogravimetría , Factores de Tiempo , Rayos Ultravioleta , Circonio/químicaRESUMEN
The objectives of this study were to evaluate physical properties and antibacterial activity of a light-activated composite modified with silver nanoparticles. Discs were produced with unmodified resin (control group - CG) and modified resin with silver nanoparticles at two concentrations, 0.3% wt (MR03) and 0.6% wt (MR06). Streptococcus mutans and Lactobacillus acidophilus biofilms were induced in vitro by incubation of discs in a 20% sucrose medium, followed by sonication and counting of viable cells after 1, 4 and 7 days (n=9). The arithmetic roughness of all three groups was evaluated by atomic force microscopy (n=9). Compression assay was conducted in all groups to measure the compressive strength at failure and elasticity modulus (n=5). Data were subjected to ANOVA and Tukey's tests (α=0.05%). At all three time points the number of viable cells was statistically lower for MR03 and MR06 compared with CG, for both specimens. MR03 and MR06 showed no significant differences. Microscopic analysis demonstrated no significant differences for roughness among the three groups (p>0.05). The MR03 was stronger to compression than CG, and MR06 was statistically lower than CG and MR03. It was concluded that the MR03 were less conducive to biofilm growth, without compromising the strength in compression and surface roughness.
Os objetivos do estudo foram avaliar as propriedades físicas e a atividade antibacteriana de uma resina composta fotopolimerizável modificada com nanopartículas de prata. Discos foram produzidos com resina não modificada (grupo controle - GC) e resina modificada com nanopartículas de prata em duas concentrações 0,3 e 0,6% em massa (MR03 e MR06, respectivamente). Biofilmes de Streptococcus mutans e Lactobacillus acidophilus foram induzidos in vitro pela incubação dos discos em meio líquido com 20% de sacarose, seguida pela sonicação e contagem de células viáveis após 1, 4 e 7 dias. A rugosidade aritmética de todos os grupos foi avaliada por microscopia de força atômica (MFA). Os dados foram submetidos à ANOVA e ao Teste de Tukey (α=0,05%). Nos três períodos de tempo, o número de células viáveis foi estatisticamente mais baixo para MR03 e MR06, em comparação com GC, para ambas as espécies. MR03 e MR06 não apresentaram diferenças significantes. A análise por meio de MFA demonstrou que não houve diferença significante para a rugosidade entre os três grupos. MR03 apresentouse mais resistente em compressão do que GC, e o desempenho em compressão em MR06 foi estatisticamente pior do que em GC e MR03. Foi possível concluír que as resinas modificadas de MR03 inibiram o crescimento dos biofilmes, sem comprometimento da resistência à compressão e da rugosidade superficial.
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Resinas Compuestas , Nanopartículas del Metal/química , Plata/química , Técnicas In Vitro , Lactobacillus acidophilus/efectos de los fármacos , Propiedades de Superficie , Plata/farmacología , Streptococcus mutans/efectos de los fármacosRESUMEN
Objective: This study aimed to evaluate the occurrence of surface changes in composite resins, when subjected to surface treatment by polishing and artificial accelerated aging. Methods: The changes were quantified through rugosimetric analysis and Scanning Electron Microscopy. Five composite resins were used (Charisma, Herculite, TPH, Z-250 and Supreme) and for each one, 32 samples were made, which were subdivided into four groups according to the surface treatment received: polished and aged, polished not aged, unpolished and aged and unpolished but not aged (control). The samples were obtained through a Teflon matrix with a diameter of 9 mm and height of 2 mm. For the polishing, the Sof-Lex Pop-On system (3M) was used and to execute the artificial accelerated aging, the Artificial Aging Machine (Comexim) was used, in which a 192 hours cycle was established, corresponding to an aging of five years. The Scanning Electron Microscopy analyses were performed under magnifications of 250x, 500x, 1000x and 2000x. All 120 samples were subjected to rugosimetric analysis through three parallel readings of each sample surface.ResultsThe Kruskal Wallis statistical test showed statistically significant differences (p <0.05) only between the type TPH composite resins, polished and either with or without aging, for the average surface roughness.ConclusionThe results showed that, for surface roughness, only the polished TPH resin showed significant differences when comparing aged and non- aged specimens. In addition, all the composite resins showed lower measurements of surface roughness when subjected to polishing treatment and higher when subjected to Artificial Aging.
Objetivo: Avaliar a ocorrência de alterações superficiais em resinas compostas quando submetidas a tratamento superficial de polimento e envelhecimento artificial acelerado. Métodos: As alterações foram quantificadas através de análise rugosimétrica e microscopia eletrônica de varredura. Foram utilizadas cinco resinas compostas (Charisma, Herculite, TPH, Z-250 e Supreme), e para cada uma delas confeccionados 32 corpos de prova que foram subdivididos em quatro grupos de oito de acordo com o tratamento superficial que receberam, sendo: polidos envelhecidos, polidos não envelhecidos, não polidos envelhecidos e não polidos não envelhecidos (controle). Os corpos de prova tinham dimensões de 9mm de diâmetro por 2mm de altura e foram obtidos através de uma matriz de teflon. Para o polimento empregou-se o sistema Sof-Lex Pop-On (3M) e para a realização do envelhecimento artificial utilizou-se a Máquina de Envelhecimento Artificial C-UV da Comexim na qual foi fixado um ciclo de 192 horas, que corresponde a cinco anos de envelhecimento. As análises ao Microscópio Eletrônico de Varredura foram realizadas com magnificações de 250x, 500x, 1,000x e 2.000x. Os 120 corpos de prova foram submetidos à análise rugosimétria através de três leituras paralelas na superfície de cada amostra. Resultados: O teste estatístico de Kruskal Wallis mostrou diferenças estatisticamente significativas (p<0,05) somente entre as resinas compostas do tipo TPH polidas com ou sem envelhecimento para a rugosidade superficial média. Conclusão: Os resultados permitiram concluir que na rugosidade superficial somente a resina TPH com polimento, mostrou diferenças significantes quando comparada envelhecida e não envelhecida e que todas as resinas compostas apresentaram medidas menores de rugosidade superficial, quando submetidas a polimento e maiores quando submetidas a Envelhecimento Artificial.
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Microscopía Electrónica de Rastreo , Pulido Dental , Resinas CompuestasRESUMEN
The aim of this study was to investigate the influence of accelerated artificial aging (AAA) on the microstructure and mechanical properties of the Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma and Filtek Z100. composite resins. The composites were characterized by Fourier-transform Infrared spectroscopy (FTIR) and thermal analyses (Differential Scanning Calorimetry - DSC and Thermogravimetry - TG). The microstructure of the materials was examined by scanning electron microscopy. Surface hardness and compressive strength data of the resins were recorded and the mean values were analyzed statistically by ANOVA and Tukey's test (α=0.05). The results showed significant differences among the commercial brands for surface hardness (F=86.74, p<0.0001) and compressive strength (F=40.31, p<0.0001), but AAA did not affect the properties (surface hardness: F=0.39, p=0.53; compressive strength: F=2.82, p=0.09) of any of the composite resins. FTIR, DSC and TG analyses showed that resin polymerization was complete, and there were no differences between the spectra and thermal curve profiles of the materials obtained before and after AAA. TG confirmed the absence of volatile compounds and evidenced good thermal stability up to 200 °C, and similar amounts of residues were found in all resins evaluated before and after AAA. The AAA treatment did not significantly affect resin surface. Therefore, regardless of the resin brand, AAA did not influence the microstructure or the mechanical properties.
A influência do sistema de envelhecimento artificial acelerado (EAA) na microestrutura e nas propriedades mecânicas das resinas compostas Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma e Filtek Z100 foi investigada. Os compósitos foram caracterizados por espectroscopia de infravermelho com transformada de Fourier (FTIR) e análises térmicas (calorimetria exploratória diferencial - DSC e termogravimetria - TG). A microestrutura dos materiais foi analisada por microscopia eletrônica de varredura. Os dados de dureza superficial e resistência à compressão foram registados para as resinas e os valores médios foram submetidos ao teste de Kolmogorov-Smirnov (p>0,05), ANOVA e teste de Tukey (α=0,05). Os resultados mostraram diferenças significativas entre as marcas comerciais em termos de dureza (F=86,74, p<0,0001) e resistência à compressão (F=40,31, p<0,0001), mas o EAA não afetou as propriedades (dureza superficial: F=0,39, p=0,53, resistência à compressão: F=2,82, p=0,09) de qualquer uma das resinas. FTIR, DSC e análise de TG revelou que a polimerização da resina foi completa, e não houve diferenças entre os espectros e os perfis de curva térmica dos materiais obtidos, antes e depois de EAA. TG mostrou a ausência de compostos voláteis e evidenciou uma boa estabilidade térmica até 200 °C, e quantidades similares de resíduos foram encontradas em todas as resinas avaliadas, antes e depois de EAA. O tratamento de EAA não afetou significativamente a superfície das resinas. Portanto, independentemente do tipo de resina, o EAA não influenciou a microestrutura e as propriedades mecânicas.
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Resinas Compuestas/química , Fuerza Compresiva , Análisis del Estrés Dental , Dureza , Técnicas In Vitro , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Polimerizacion , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Dióxido de Silicio/química , Termogravimetría , Factores de Tiempo , Rayos Ultravioleta , Circonio/químicaRESUMEN
Objetivo: O objetivo deste trabalho foi avaliar a influência do envelhecimento artificial acelerado na resistência à compressão de resinas compostas. Metodologia: Foram avaliadas cinco marcas comerciais de resinas compostas: Z250®, 4Seasons®, P60®, Z100® e Charisma®. Para cada resina foram obtidos 16 corpos de prova, divididos em dois grupos de oito, sendo um grupo submetido ao sistema envelhecimento acelerado para não metálicos CUV e o outro, à análise de resistência à compressão 24 horas após sua obtenção. Posteriormente, os corpos de prova envelhecidos foram submetidos ao ensaio de compressão. As médias das leituras de resistência à compressão de cada corpo de prova foram submetidas ao teste Kolmogorov-Smirnov (p > 0,05), Anova e teste de Tukey (p < 0,05). Resultados: A análise dos fatores apresentou diferenças significantes entre as marcas de resina composta quanto à resistência à compressão (F = 40,31, p < 0,0001). Com relação ao mesmo material antes e depois do envelhecimento, nota-se que esse processo não influenciou na resistência a compressão de nenhuma das resinas compostas (F = 2,82, p = 0,09). Nota-se que houve interação entre os fatores marca da resina composta e envelhecimento (F = 3,20, p < 0,004). Conclusão: Independentemente do tipo de resina, o envelhecimento artificial acelerado não influenciou na resistência à compressão. No entanto, houve diferença significante entre as marcas de resina quanto a essa propriedade.
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Este estudo avaliou a rugosidade superficial dos gessos Tipo IV e V e de uma resina epóxica pura e uma carregada com zirconita. Para a análise da rugosidade, os polímeros e os gessos foram vertidos em matrizes hexagonais apoiadas em lâmina de vidro, permitindo, após endurecimento dos materiais, três leituras em cada corpo-de-prova. Este estudo também avaliou a compatibilidade do polímero puro e da resina carregada com zirconita quando em contato com materiais elastoméricos utilizando dois critérios: aderência do molde e alteração na coloração do modelo. Para a análise da compatibilidade, os polímeros foram colocados em contato com quatro diferentes elastômeros e, após endurecimento dos materiais, realizou-se a inspeção com lupa de quatro aumentos. A resina foi 100% compatível com os materiais de moldagem. Com análise de variância e teste Tukey com significância 5%, verificou-se que não há diferença entre o gesso IV e o gesso V e que não há diferença entre a resina epóxica pura e a modificada com zirconita. Na comparação entre gessos e resinas, verificou-se que há diferença estatisticamente significante. Concluiu-se que: a adição de zirconita na proporção de 1/1 em peso na resina epóxica Epoxiglass 1504 e no endurecedor Epoxiglass 1603 proporcionou um material resinoso para obtenção de modelos compatível com os elastômeros mercaptana, poliéter, silicona de condensação e de adição; quando comparada aos gessos tipos IV e V, a resina epóxica Epoxiglass 1504 possibilitou obtenção de modelos com superior lisura superficial; a adição de zirconita na proporção de 1/1 na resina epóxica não comprometeu sua lisura superficial.
This study evaluated the surface roughness of Type IV and V dental plasters and epoxy resin with and without zirconite filler. To analyze the roughness, the polymers and plasters were poured into hexagonal dies supported on a sheet of glass, allowing, after hardening of the materials, for three readings of each test specimen. An evaluation was also made of the compatibility of this polymer, with and without zirconite filler, when in contact with elastomeric materials, based on two criteria: adherence of the die and alteration in the color of the model. To analyze the compatibility, the polymers were put into contact with four different elastomers and, after the materials hardened, they were examined with a magnifying glass with four times magnification. The resin was found to be 100% compatible with the molding materials. A variance analysis and Tukeys test with 5% significance indicated that there was no difference between the IV and the V plasters, and that there was no difference between the pure epoxy resin and resin modified with zirconite. A comparison between plasters and resins revealed a statistically significant difference. It was concluded that the addition of zirconite in a 1:1 wt ratio to Epoxyglass 1504 resin and to Epoxyglass 1603 hardener produced a resinous material suitable for producing models compatible with the elastomers mercaptan, polyether, condensation silicone and silicone additive. When compared with the IV and V type plasters, the resinous epoxy Epoxyglass 1504 produced models with superior surface smoothness. The addition of zirconite in a proportion of 1:1 to epoxy resin did not affect the surface smoothness.
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Elastómeros , Modelos Dentales , Resinas Epoxi , Sulfato de CalcioRESUMEN
Poli e-caprolactona é um importante polímero biodegradável e miscível com o PVC, um polímero sintético industrial, termo susceptível e não biodegradável. A blenda PVC/PCL é importante em propriedades mecânicas e biodegradabilidade. Neste trabalho, há indicações que há interação dos microrganismos com a superfície polimérica e esta causa mudanças estruturais na blenda PVC/PCL.
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Poly (caprolactone) is a famous biodegradable polymer and miscible with PVC, a commercial synthetic polymer, thermal susceptible and non-biodegradable. This blend is important concerning its mechanical properties and biodegradability. In this work, we testified the biomodification of blend films of PVC/PCL by UV-Vis. spectroscopy. The results show us that there is an interaction between the PVC/PCL film and the microrganisms.
Poli épsilon-caprolactona é um importante polímero biodegradável e miscível com o PVC, um polímero sintético industrial, termo susceptível e não biodegradável. A blenda PVC/PCL é importante em propriedades mecânicas e biodegradabilidade. Neste trabalho, há indicações que há interação dos microrganismos com a superfície polimérica e esta causa mudanças estruturais na blenda PVC/PCL.