Base de dados : LILACS
Pesquisa : G01.645 [Categoria DeCS]
Referências encontradas : 23 [refinar]
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Id: biblio-889495
Autor: Gonçalves, Flávia; Campos, Luiza Mello de Paiva; Rodrigues-Júnior, Ezequias Costa; Costa, Fabrícia Viana; Marques, Pamela Adeline; Francci, Carlos Eduardo; Braga, Roberto Ruggiero; Boaro, Letícia Cristina Cidreira.
Título: A comparative study of bulk-fill composites: degree of conversion, post-gel shrinkage and cytotoxicity
Fonte: Braz. oral res. (Online);32:e17, 2018. tab, graf.
Idioma: en.
Projeto: FAPESP.
Resumo: Abstract: Bulk-fill composites are claimed to be restorative materials used in deep preparations and effectively photoactivated in layers up to 4 mm. The aim of the present study was to evaluate the degree of conversion, post-gel volumetric shrinkage, and cytotoxicity of six bulk-fill and two conventional composites. Degree of conversion was determined by FTIR spectroscopy; post-gel volumetric shrinkage was determined using the strain gauge method; and cytotoxicity in human fibroblasts was evaluated indirectly by the MTT assay. Data were subjected to one-way ANOVA/Tukey's test (α = 0.05). All materials, including bulk-fill and conventional composites, were classified as non-toxic, with cell viability higher than 70%. Bulk-fill composites exhibited volumetric shrinkage similar to or lower (1.4 to 0.4%) than that of conventional composites (1.7-2.1%). However, only four of the bulk-fill composites were able to sustain a homogeneous conversion at the 4-mm depth. Despite their non-toxicity and shrinkage similar to that of conventional materials, not all commercial bulk-fill materials were able to maintain a conversion as high as 80% of the superficial layer, at the 4-mm depth, indicating some failure in the bulk-fill design of some commercial brands. Therefore, the use of bulk-fill materials in dental practice is advantageous, but special attention should be given to the selection and correct use of the materials.
Descritores: Resinas Compostas/toxicidade
Resinas Compostas/química
Polimerização
-Valores de Referência
Propriedades de Superfície
Fatores de Tempo
Teste de Materiais
Sobrevivência Celular/efeitos dos fármacos
Reprodutibilidade dos Testes
Análise de Variância
Espectroscopia de Infravermelho com Transformada de Fourier
Transição de Fase
Processos Fotoquímicos
Fibroblastos/efeitos dos fármacos
Limites: Humanos
Tipo de Publ: Estudo Comparativo
Responsável: BR1.1 - BIREME


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Id: biblio-889485
Autor: ALMEIDA, Carianne Mendes de; MEEREIS, Carine Tais Welter; LEAL, Fernanda Barbosa; OGLIARI, Aline Oliveira; PIVA, Evandro; OGLIARI, Fabrício A.
Título: Evaluation of long-term bond strength and selected properties of self-adhesive resin cements
Fonte: Braz. oral res. (Online);32:e15, 2018. tab, graf.
Idioma: en.
Projeto: Conselho Nacional de Pesquisa.
Resumo: Abstract This study evaluated the shear bond strength (SBS) of self-adhesive resin cements (SARCs) to dentin and their physical-chemical properties. Five commercial SARCs were evaluated [SmartCem®2 - DENTSPLY (SC2); BisCem® - Bisco (BC); SeT PP® − SDI (SeT); Relyx U100® - 3M ESPE (U100) and YCEM® SA - Yller (YCEM)]. The SARCs were evaluated for SBS to dentin (n = 10) after 24 h, 6 months, and 12 months. The dentin demineralization caused by acidic monomers was observed by SEM, and pH-neutralization of eluate was observed for 24 h. Degree of conversion (DC), rate of polymerization (Rp), flexural strength (FS), and elastic modulus (E) were evaluated. Immediate SBS of SC2, SET, U100, and YCEM were statistically higher than that of BC (p < 0.001). After 12 months, all SARCs showed reduced SBS values and U100 showed values similar to those of SET and YCEM, and higher than those of BC and SC2 (p = 0.001). Demineralization pattern of SARCs was similar. At 24h, all SARCs showed no differences in the pH-value, except BC and U100 (p < 0.001). YCEM showed the highest Rp. U100, YCEM, and SC2 showed statistically higher FS (p<0.001) and E (p < 0.001) when compared with SET and BC. U100 and YCEM showed the best long-term bonding irrespective of the storage period. A significant reduction in SBS was found for all groups after 12 months. SBS was not shown to be correlated with physical-chemical properties, and appeared to be material-dependent. The polymerization profile suggested that an increased time of light activation, longer than that recommended by manufacturers, would be necessary to optimize DC of SARCs.
Descritores: Resinas Compostas/química
Cimentos de Resina/química
Dentina/efeitos dos fármacos
Cura Luminosa de Adesivos Dentários/métodos
-Valores de Referência
Propriedades de Superfície/efeitos dos fármacos
Fatores de Tempo
Teste de Materiais
Microscopia Eletrônica de Varredura
Reprodutibilidade dos Testes
Análise de Variância
Maleabilidade
Resistência ao Cisalhamento
Dentina/química
Transição de Fase/efeitos dos fármacos
Módulo de Elasticidade
Polimerização
Tipo de Publ: Estudo de Avaliação
Responsável: BR1.1 - BIREME


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Id: biblio-841182
Autor: CARDOSO, Kelly Antonieta Oliveira Rodrigues de Faria; ZARPELLON, Driellen Christine; MADRUGA, Camila Ferreira Leite; RODRIGUES, José Augusto; ARRAIS, Cesar Augusto Galvão.
Título: Effects of radiant exposure values using second and third generation light curing units on the degree of conversion of a lucirin-based resin composite
Fonte: J. appl. oral sci;25(2):140-146, Mar.-Apr. 2017. tab, graf.
Idioma: en.
Projeto: FAPESP.
Resumo: Abstract Alternative photoinitiators with different absorption wavelengths have been used in resin composites (RCs), so it is crucial to evaluate the effectiveness of light-curing units (LCUs) on these products. Objective Using Fourier transform infrared analysis (FTIR) in vitro, the effects of varying radiant exposure (RE) values generated by second and third generation LED LCUs on the degree of conversion (DC) and maximum rate of polymerization (Rpmax) of an experimental Lucirin TPO-based RC were evaluated. Material and Methods 1 mm or 2 mm thick silicon molds were positioned on a horizontal attenuated total reflectance (ATR) unit attached to an infrared spectroscope. The RC was inserted into the molds and exposed to varying REs (18, 36 and 56 J/cm2) using second (Radii Plus, SDI) and third generation LED LCUs (Bluephase G2/Ivoclar Vivadent) or a quartz tungsten based LCU (Optilux 501/SDS Kerr). FTIR spectra (n=7) were recorded for 10 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm-1) immediately after their application to the ATR. The DC was calculated using standard techniques for observing changes in aliphatic to aromatic peak ratios both prior to, and 10 min after curing, as well as during each 1 second interval. DC and Rpmax data were analyzed using 3-way ANOVA and Tukey’s post-hoc test (p=0.05). Results No significant difference in DC or Rpmax was observed between the 1 mm or 2 mm thick specimens when RE values were delivered by Optilux 501 or when the 1 mm thick composites were exposed to light emitted by Bluephase G2, which in turn promoted a lower DC when 18 J/cm2 (13 s) were delivered to the 2 mm thick specimens. Radii Plus promoted DC and Rpmax values close to zero under most conditions, while the delivery of 56 J/cm2 (40 s) resulted in low DC values. Conclusions The third generation LCU provided an optimal polymerization of Lucirin TPO-based RC under most tested conditions, whereas the second generation LED-curing unit was useless regardless of the RE.
Descritores: Fosfinas/efeitos da radiação
Resinas Compostas/efeitos da radiação
Cura Luminosa de Adesivos Dentários/métodos
Luzes de Cura Dentária
-Doses de Radiação
Valores de Referência
Fatores de Tempo
Teste de Materiais
Reprodutibilidade dos Testes
Análise de Variância
Espectroscopia de Infravermelho com Transformada de Fourier
Transição de Fase
Fotoiniciadores Dentários/química
Polimerização/efeitos da radiação
Tipo de Publ: Estudo de Avaliação
Responsável: BR1.1 - BIREME


  4 / 23 LILACS  
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Id: biblio-841154
Autor: OLIVEIRA, Dayane Carvalho Ramos Salles de; SOUZA-JUNIOR, Eduardo José; DOBSON, Adam; CORRER, Ana Rosa Costa; BRANDT, William Cunha; SINHORETI, Mário Alexandre Coelho.
Título: Evaluation of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental dental resin-based materials
Fonte: J. appl. oral sci;24(6):555-560, Nov.-Dec. 2016. tab, graf.
Idioma: en.
Projeto: São Paulo Research Foundation.
Resumo: ABSTRACT Objective To evaluate the influence of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental resin-based materials photoactivated using different light curing units (LCUs). Material and Methods Experimental resin-based materials with the same organic matrix (60:40 wt% BisGMA:TEGDMA) were mechanically blended using a centrifugal mixing device. To this blend, different photoinitiator systems were added in equimolar concentrations with aliphatic amine doubled by wt%: 0.4 wt% CQ; 0.38 wt% PPD; or 0.2 wt% CQ and 0.19 wt% PPD. The degree of conversion (DC), flexural strength (FS), Young’s modulus (YM), Knoop hardness (KNH), crosslinking density (CLD), and yellowing (Y) were evaluated (n=10). All samples were light cured with the following LCUs: a halogen lamp (XL 2500), a monowave LED (Radii), or a polywave LED (Valo) with 16 J/cm2. The results were analysed by two-way ANOVA and Tukey’s test (α=0.05). Results No statistical differences were found between the different photoinitiator systems to KNH, CLS, FS, and YM properties (p≥0.05). PPD/CQ association showed the higher DC values compared with CQ and PPD isolated systems when photoactivated by a polywave LED (p≤0.05). Y values were highest for the CQ compared with the PPD systems (p≤0.05). Conclusion PPD isolated system promoted similar chemical and mechanical properties and less yellowing compared with the CQ isolated system, regardless of the LCU used.
Descritores: Polietilenoglicóis/química
Ácidos Polimetacrílicos/química
Bis-Fenol A-Glicidil Metacrilato/química
Chalconas/química
Cura Luminosa de Adesivos Dentários/métodos
Fotoiniciadores Dentários/química
-Espectrofotometria
Teste de Materiais
Cânfora/análogos & derivados
Cânfora/química
Reprodutibilidade dos Testes
Espectroscopia de Infravermelho com Transformada de Fourier
Pigmentação em Prótese
Cor
Estatísticas não Paramétricas
Maleabilidade
Transição de Fase
Luzes de Cura Dentária
Módulo de Elasticidade
Polimerização
Testes de Dureza
Tipo de Publ: Estudo Comparativo
Estudo de Avaliação
Responsável: BR1.1 - BIREME


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Id: biblio-893641
Autor: BRIANEZZI, Leticia Ferreira de Freitas; MAENOSONO, Rafael Massunari; BIM JÚNIOR, Odair; ZABEU, Giovanna Speranza; PALMA-DIBB, Regina Guenka; ISHIKIRIAMA, Sérgio Kiyoshi.
Título: Does laser diode irradiation improve the degree of conversion of simplified dentin bonding systems?
Fonte: J. appl. oral sci;25(4):381-386, July-Aug. 2017. tab, graf.
Idioma: en.
Resumo: Abstract Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC), water sorption (WS), and water solubility (WSB) of these bonding systems in an attempt to improve their physico-mechanical resistance. Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB)] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU)]. Square-shaped specimens were prepared and assigned into 4 groups (n=5): SB and SU (control groups - no laser irradiation) and SB-L and SU-L [SB and SU laser (L) - irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5) of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10) were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm), irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2). Results Laser irradiation immediately before photopolymerization increased the DC (%) of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3), only the dentin bonding system (DBS) was a significant factor (p<0.05): SB>SU. Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.
Descritores: Adesivos Dentinários/efeitos da radiação
Lasers Semicondutores
Polimerização/efeitos da radiação
-Luzes de Cura Dentária
Cimentos Dentários/química
Cimentos Dentários/efeitos da radiação
Adesivos Dentinários/química
Cura Luminosa de Adesivos Dentários/métodos
Transição de Fase/efeitos da radiação
Processos Fotoquímicos/efeitos da radiação
Valores de Referência
Reprodutibilidade dos Testes
Solubilidade/efeitos da radiação
Espectroscopia de Infravermelho com Transformada de Fourier
Estatísticas não Paramétricas
Propriedades de Superfície/efeitos da radiação
Tipo de Publ: Estudo de Avaliação
Responsável: BR1.1 - BIREME


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Id: biblio-889493
Autor: Genari, Bruna; Leitune, Vicente Castelo Branco; Jornada, Denise Soledade; Aldrigui, Bibiana Rocha; Pohlmann, Adriana Raffin; Guterres, Sílvia Stanisçuaski; Samuel, Susana Maria Werner; Collares, Fabrício Mezzomo.
Título: Effect on adhesion of a nanocapsules-loaded adhesive system
Fonte: Braz. oral res. (Online);32:e008, 2018. tab.
Idioma: en.
Resumo: Abstract This study aimed to evaluate the in situ degree of conversion, contact angle, and immediate and long-term bond strengths of a commercial primer and an experimental adhesive containing indomethacin- and triclosan-loaded nanocapsules (NCs). The indomethacin- and triclosan-loaded NCs, which promote anti-inflammatory and antibacterial effects through controlled release, were incorporated into the primer at a concentration of 2% and in the adhesive at concentrations of 1, 2, 5, and 10%. The in situ degree of conversion (DC, n=3) was evaluated by micro-Raman spectroscopy. The contact angle of the primer and adhesive on the dentin surface (n = 3) was determined by an optical tensiometer. For the microtensile bond strength µTBS test (12 teeth per group), stick-shaped specimens were tested under tensile stress immediately after preparation and after storage in water for 1 year. The data were analyzed using two-way ANOVA, three-way ANOVA and Tukey's post hoc tests with α=0.05. The use of the NC-loaded adhesive resulted in a higher in situ degree of conversion. The DC values varied from 75.07 ± 8.83% to 96.18 ± 0.87%. The use of NCs in only the adhesive up to a concentration of 5% had no influence on the bond strength. The contact angle of the primer remained the same with and without NCs. The use of both the primer and adhesive with NCs (for all concentrations) resulted in a higher contact angle of the adhesive. The longitudinal μTBS was inversely proportional to the concentration of NCs in the adhesive system, exhibiting decreasing values for the groups with primer containing NCs and adhesives with increasing concentrations of NCs. Adhesives containing up to 5% of nanocapsules and primer with no NCs maintained the in situ degree of conversion, contact angle, and immediate and long-term bond strengths. Therefore, the NC-loaded adhesive can be an alternative method for combining the bond performance and therapeutic effects. The use of an adhesive with up to 5% nanocapsules containing indomethacin and triclosan and a primer with no nanocapsules maintained the long-term bond performance.
Descritores: Colagem Dentária/métodos
Indometacina/química
Nanocápsulas/química
Cimentos de Resina/química
Triclosan/química
-Análise de Variância
Falha de Restauração Dentária
Dentina/efeitos dos fármacos
Teste de Materiais
Transição de Fase/efeitos dos fármacos
Polimerização/efeitos dos fármacos
Valores de Referência
Reprodutibilidade dos Testes
Análise Espectral Raman
Propriedades de Superfície/efeitos dos fármacos
Resistência à Tração
Fatores de Tempo
Limites: Animais
Bovinos
Tipo de Publ: Estudo de Avaliação
Responsável: BR1.1 - BIREME


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Id: biblio-882831
Autor: Melo, Gislane Ferreira de; Rubio, Katia.
Título: Mulheres atletas olímpicas brasileiras: início e final de carreira por modalidade esportiva / Brazilian olympic athletes women: initial and final career by sports modality
Fonte: Rev. bras. ciênc. mov;25(4):104-116, out.- dez.2017. tab, ilus.
Idioma: pt.
Resumo: Este estudo buscou investigar o contexto e a idade de início e final de carreira das mulheres atletas olímpicas brasileiras, bem como a razão do encerramento da carreira. Para tanto, participaram da amostra 444 mulheres brasileiras participantes de Jogos Olímpicos até Londres em 2012. Dos relatos de vida, foram retirados dados relacionados aos objetivos deste estudo. Os resultados nos permitem inferir que, em modalidades como natação, ginástica e tênis, o início foi muito precoce, já nos esportes coletivos a idade de início corresponde à fase escolar, quando neste momento o profissional de Educação Física é o principal responsável pela iniciação ao rendimento. Esportes como tiro, arco, boxe e levantamento de peso têm seu início já no final da adolescência. Com relação ao final de carreira, a faixa etária de aposentadoria corresponde à modalidade, e naqueles esportes em que se começa cedo, as idades de aposentadoria são menores. Observou-se também que os motivos principais para a finalização da carreira são: número de lesões, fadiga e cansaço, percepção de que a idade estava atrapalhando, maternidade e casamento e a necessidade de continuar os estudos. Outro fato abordado foi a exclusão da atleta pela comissão técnica, o que foi determinante para que a atleta não quisesse mais fazer parte daquele meio. A escolha de uma nova profissão e outro fator importante e que nos apresenta um panorama diferenciado para as atletas olímpicas, já que 50% destas se formaram e hoje, a grande maioria (65%) trabalham na área esportiva. Pode-se concluir que cada modalidade tem o momento ideal de início e que as atletas olímpicas não saíram deste padrão. Quanto ao término da carreira, este pode não ser compulsório (lesões, cansaço e fadiga, dispensas da equipe, maternidade, casamento) ou programado (formação acadêmica e profissional, necessidade de novas metas)....(AU)

The purpose of this study was to investigate the context of Brazilian women athletes, specifically the age at which they began and ended their careers, the reason for ending their careers and surrounding factors. For that, the sample was attended by 444 Brazilian women participating in the Olympic Games until London in 2012. Data related to the objectives of this study were collected from self-reports from the athletes. The results showed that in modalities such as swimming, gymnastics and tennis, the starting age for athletes was very young. In collective sports, the starting age corresponded to the age of schooling, wherein Physical Education is responsible for the initiation to the sport. Sports such as shooting, archery, boxing and weight lifting have their beginning as early as the end of adolescence. The age of retirement was found to correspond with the modality, whereby those sports that are begun at an early age were found to be associated with earlier retirement ages. It was also noted that the main reasons for career completion are: multiple injuries, fatigue, distress caused by self-perception of old age, maternity and marriage, and the continuation of studies. Another factor addressed was the exclusion of an athlete by a technical committee, acting as a driving force for the athlete to no longer want to be part of the sport environment. Following departure from a sport, the choice of a new profession is another important factor that presents us with a view of the Olympic athletes, since 50% of retired athletes went on to complete undergraduate degrees and the vast majority (605) went on to work in sport. It can be concluded that each modality has an ideal age at which to begin the sport and the Olympic athletes adhered to this standard. As for the end of the careers, the age of completion cannot be programmed in some cases (e.g. due to injuries, fatigue, team layoffs, maternity, marriage) and can be programmed in other cases (academic and professional training, need for new goals)....(AU)
Descritores: Efeito Idade
Atletas
Transição de Fase
Educação Física e Treinamento
Esportes
Mulheres
-Provas de Rendimento
Limites: Humanos
Feminino
Criança
Adolescente
Adulto
Responsável: BR1552.1 - Biblioteca Central


  8 / 23 LILACS  
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Id: biblio-841155
Autor: KÖROĞLU, Ayşegül; ŞAHİN, Onur; KÜRKÇÜOĞLU, Işın; DEDE, Doğu Ömür; ÖZDEMİR, Tonguç; HAZER, Baki.
Título: Silver nanoparticle incorporation effect on mechanical and thermal properties of denture base acrylic resins
Fonte: J. appl. oral sci;24(6):590-596, Nov.-Dec. 2016. tab, graf.
Idioma: en.
Resumo: ABSTRACT Objective The aim of the present study was to evaluate the mechanical and thermal characteristics of two denture base acrylic resins containing silver nanoparticles (AgNPs). Material and Methods Two different acrylic denture base resins (heat-polymerized and microwave polymerized) containing 0.3, 0.8 and 1.6 wt% AgNPs were evaluated for flexural strength, elastic modulus and impact strength. The glass transition temperature (Tg) and relative heat capacity (Cp) of the samples were determined from the Differential Scanning Calorimetry (DSC) results. For statistical analysis, two-way ANOVA and Tukey-HSD tests were performed. Results Addition of 0.8% and 1.6% AgNPs in microwave-polymerized resin significantly decreased the transverse strength and elastic modulus. In terms of impact strength, the addition of AgNPs has no effect on both resin groups. Glass transition temperature (Tg) was decreased with the addition of AgNPs for both denture base resins. Conclusions The incorporation of AgNPs, generally used for antimicrobial efficiency, affected the transverse strength of the denture base acrylic resins depending on the concentration of nanoparticles. Tg was decreased with the addition of AgNPs for both denture base resins.
Descritores: Resinas Acrílicas/química
Bases de Dentadura
Nanopartículas Metálicas/química
Prata/química
-Análise de Variância
Varredura Diferencial de Calorimetria
Módulo de Elasticidade
Vidro/química
Teste de Materiais
Tamanho da Partícula
Transição de Fase
Maleabilidade
Polimerização
Valores de Referência
Reprodutibilidade dos Testes
Fatores de Tempo
Tipo de Publ: Estudo de Avaliação
Responsável: BR1.1 - BIREME


  9 / 23 LILACS  
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Id: biblio-839505
Autor: COLLARES, Fabrício Mezzomo; LEITUNE, Vicente Castelo Branco; FRANKEN, Patrícia; PAROLLO, Clarissa Fatturi; OGLIARI, Fabrício Aulo; SAMUEL, Susana Maria Werner.
Título: Influence of addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride to an experimental adhesive
Fonte: Braz. oral res. (Online);31:e31, 2017. tab, graf.
Idioma: en.
Resumo: Abstract The aim of this study was to develop an experimental adhesive with addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) and to evaluate its mechanical and biological properties and its in vitro antibacterial activity. An experimental adhesive resin was formulated with Bis-GMA, TEGDMA, and HEMA. The antibacterial monomer was added at concentrations of 1%, 2.5%, and 5% (METAC groups). A group without METAC addition was used as control. The experimental adhesives were evaluated as to their antibacterial potential against Streptococcus mutans, degree of conversion, and softening in ethanol for 2 hours. The data were analyzed by one-way ANOVA, Tukey’s post-hoc test, and the paired Student’s t-test (significance level of 0.05). METAC showed antibacterial activity against S. mutans at all concentrations (p < 0.05). There was no statistical difference across METAC groups (p > 0.05). The 1%, 2.5%, and 5% groups yielded the highest mean values for degree of conversion (p < 0.05). The 1% group did not differ from the control group (p > 0.05). There was no statistical difference in baseline microhardness values (p > 0.05) and microhardness values after immersion in ethanol were lower than at baseline for all groups (p < 0.05). There was no statistical difference in the reduction of Knoop hardness number (KHN) after immersion in ethanol for any of the groups (p > 0.05). The results of the present study indicate that METAC is a promising antibacterial agent when added to an adhesive system.
Descritores: Antibacterianos/química
Bis-Fenol A-Glicidil Metacrilato/química
Resinas Compostas/química
Metacrilatos/química
Polietilenoglicóis/química
Ácidos Polimetacrílicos/química
-Análise de Variância
Antibacterianos/farmacologia
Bis-Fenol A-Glicidil Metacrilato/farmacologia
Contagem de Colônia Microbiana
Resinas Compostas/farmacologia
Testes de Dureza
Imersão
Teste de Materiais
Metacrilatos/farmacologia
Transição de Fase
Polietilenoglicóis/farmacologia
Polimerização
Ácidos Polimetacrílicos/farmacologia
Reprodutibilidade dos Testes
Streptococcus mutans/efeitos dos fármacos
Tipo de Publ: Estudo de Avaliação
Responsável: BR1.1 - BIREME


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Id: lil-777197
Autor: GONÇALVES, Flávia; BOARO, Leticia Cristina Cidreira; MIYAZAKI, Caroline Lumi; KAWANO, Yoshio; BRAGA, Roberto Ruggiero.
Título: Influence of polymeric matrix on the physical and chemical properties of experimental composites
Fonte: Braz. oral res. (Online);29(1):1-7, 2015. tab, ilus.
Idioma: en.
Resumo: Nowadays, the main reasons for replacement of resin-based composite restorations are fracture or problems with the integrity of their interface, such as marginal staining, microleakage, or secondary caries. The aim of the present study was to evaluate the influence of the organic matrix on polymerization stress (PS), degree of conversion (DC), elastic modulus (E), flexural strength (FS), Knoop hardness (KHN), sorption (SP), and solubility (SL). In order to obtain a material which combines better mechanical properties with lower PS, seven experimental composites were prepared using BisGMA to TEGDMA molar ratios of 2:8, 3:7, 4:6, 5:5, 6:4, 7:3 and 8:2 and 40% of silica. PS was obtained in a universal testing machine, using acrylic as bonding substrate. DC was determined using Fourier Transform Raman spectroscopy. E and FS were obtained by the three-point bending test. KHN was measured by a microindentation test using a load of 25 g for 30 s. SP and SL were assessed according to ISO 4049. The data were submitted to one-way ANOVA. The increase in BisGMA concentration resulted in the decrease of PS, DC, E, FS and KHN. However, it did not change the SP and SL values. FS, E and KHN showed a strong and direct relationship with the DC of the materials. The composite material with a BisGMA to TEGDMA molar ratio of 1:1 was the one with better mechanical properties and lower PS.
Descritores: Resinas Compostas/química
Análise do Estresse Dentário
Metacrilatos/química
Polietilenoglicóis/química
Polimerização/efeitos dos fármacos
Ácidos Polimetacrílicos/química
-Adsorção
Análise de Variância
Módulo de Elasticidade
Testes de Dureza
Teste de Materiais
Transição de Fase/efeitos dos fármacos
Fotoiniciadores Dentários/química
Maleabilidade
Valores de Referência
Reprodutibilidade dos Testes
Solubilidade
Espectroscopia de Infravermelho com Transformada de Fourier
Fatores de Tempo
Responsável: BR1.1 - BIREME



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