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For nearly three decades, tissue engineering strategies have been leveraged to devise effective therapeutics for dental, oral, and craniofacial (DOC) regenerative medicine and treat permanent deformities caused by many debilitating health conditions. In this regard, additive manufacturing (AM) allows the fabrication of personalized scaffolds that have the potential to recapitulate native tissue morphology and biomechanics through the utilization of several 3D printing techniques. Among these, melt electrowriting (MEW) is a versatile direct electrowriting process that permits the development of well-organized fibrous constructs with fiber resolutions ranging from micron to nanoscale. Indeed, MEW offers great prospects for the fabrication of scaffolds mimicking tissue specificity, healthy and pathophysiological microenvironments, personalized multi-scale transitions, and functional interfaces for tissue regeneration in medicine and dentistry. Excitingly, recent work has demonstrated the potential of converging MEW with other AM technologies and/or cell-laden scaffold fabrication (bioprinting) as a favorable route to overcome some of the limitations of MEW for DOC tissue regeneration. In particular, such convergency fabrication strategy has opened great promise in terms of supporting multi-tissue compartmentalization and predetermined cell commitment. In this review, we offer a critical appraisal on the latest advances in MEW and its convergence with other biofabrication technologies for DOC tissue regeneration. We first present the engineering principles of MEW and the most relevant design aspects for transition from flat to more anatomically relevant 3D structures while printing highly-ordered constructs. Secondly, we provide a thorough assessment of contemporary achievements using MEW scaffolds to study and guide soft and hard tissue regeneration, and draw a parallel on how to extrapolate proven concepts for applications in DOC tissue regeneration. Finally, we offer a combined engineering/clinical perspective on the fabrication of hierarchically organized MEW scaffold architectures and the future translational potential of site-specific, single-step scaffold fabrication to address tissue and tissue interfaces in dental, oral, and craniofacial regenerative medicine. STATEMENT OF SIGNIFICANCE: Melt electrowriting (MEW) techniques can further replicate the complexity of native tissues and could be the foundation for novel personalized (defect-specific) and tissue-specific clinical approaches in regenerative dental medicine. This work presents a unique perspective on how MEW has been translated towards the application of highly-ordered personalized multi-scale and functional interfaces for tissue regeneration, targeting the transition from flat to anatomically-relevant three-dimensional structures. Furthermore, we address the value of convergence of biofabrication technologies to overcome the traditional manufacturing limitations provided by multi-tissue complexity. Taken together, this work offers abundant engineering and clinical perspectives on the fabrication of hierarchically MEW architectures aiming towards site-specific implants to address complex tissue damage in regenerative dental medicine.

The aim of this study was to evaluate physical-mechanical properties, degree of conversion, and chemical stability of a nanohybrid composite containing diatomite as filler. Degree of conversion (DC%) of diatomite-containing composite (Zirconfill®) was performed using FTIR immediately, and 1-, and 7-days post-curing. SEM was conducted to evaluate the surface of the resin after curing and measure particles size. Also, elemental characterization was performed to verify the major components of the composite through EDS. Mechanical characterization using 3-point bending test was performed prior and after thermo-cycling (10000 cycles) (n=10). Knoop microhardness (KHN) was used to characterize mechanical stability after chemical solutions aggression (water, juice, coffee, coke) up to 28 days (n=10/solution). After data normality evaluation using Shapiro-Wilk, One-way ANOVA and Tukey post hoc were conducted to verify differences between groups for DC% and mechanical properties. Split-plot ANOVA was used to compare groups for microhardness characterization (α=0.05). Immediate DC was 60% and significantly increased up to 80% at 7 days (p0.05). All the dietary solutions affected the KHN of the composite up to 21 days. For 28 days, the KHN evidenced and stabilization regarding all the solutions. Diatomite-containing composites present good degree of conversion and relevant mechanical properties and demonstrate time-dependent stability against chemical degradation. El objetivo de este estudio fue evaluar las propiedades físico-mecánicas, el grado de conversión y la estabilidad química de un compuesto nanohíbrido que contiene diatomita como relleno. El grado de conversión (DC%) del compuesto que contiene diatomeas (Zirconfill®) se realizó usando FTIR inmediatamente y 1 y 7 días después del curado. Se realizó SEM para evaluar la superficie después del curado y medir las partículas. Se realizó la caracterización elemental para verificar los componentes mayoritarios del compuesto a través de EDS. La caracterización mecánica mediante la prueba de flexión de 3 puntos se realizó antes y después del termociclado (10000 ciclos) (n = 10). Se utilizó la microdureza Knoop (KHN) para caracterizar la estabilidad mecánica después de la agresión de soluciones químicas (agua, jugo, café, coque) hasta 28 días (n=10/solución). Después de la evaluación de la normalidad de los datos usando Shapiro-Wilk, se realizaron ANOVA unidireccional y post hoc de Tukey para verificar las diferencias entre los grupos para el % de DC y las propiedades mecánicas. Se usó ANOVA de parcela dividida para comparar grupos para la caracterización de microdureza (α = 0.05). La DC inmediata fue del 60 % y aumentó significativamente hasta el 80 % a los 7 días (p0.05). Todas las soluciones dietéticas afectaron el KHN del compuesto hasta 21 días. Durante 28 días, la KHN evidenció una estabilización respecto a todas las soluciones. Los compuestos que contienen diatomita presentan un buen grado de conversión y propiedades mecánicas relevantes y demuestran una estabilidad dependiente del tiempo frente a la degradación química. O objetivo deste estudo foi avaliar as propriedades físico-mecânicas, grau de conversão e estabilidade química de um compósito nano-híbrido contendo carga de diatomita. O grau de conversão (DC%) do compósito contendo diatomita (Zirconfill®) foi avaliado utilizando FTIR imediatamente, 1 dia e 7 dias após a polimerização. Microscopia Eletrônica de Varredura foi utilizada para avaliar a microestrutura após a polimerização e medir as partículas. A análise elementar dos componentes do compósito foi realizada por meio de EDS. A caracterização mecânica foi realizada utilizando flexão de três pontos (n=10) antes e após termo-ciclagem (10000 ciclos). Microdureza knoop (KHN) foi usada para caracterizar a estabilidade mecânica após agressão por agentes químicos da dieta (água, suco, café e refrigerante) até 28 dias (n=10/solução). A normalidade dos dados foi verificada pelo teste Shapiro-Wilk. Anova One-way e Tukey post hoc foram conduzidos para verificar diferenças para o grau de conversão e flexão. Anova de medidas repetidas foi usada para comparer os grupos para microdureza (α=0.05). O grau de conversão imediato foi de 60% e aumentou significativamente (80%) após 7 dias (p0.05). O módulo flexural também não foi afetado pela termociclagem. Todas as soluções testadas afetaram a KHN do compósito até 21 dias. Para 28 dias, os valores de KHN estabilizaram para todas as soluções. O compósito contendo diatomita demonstra bom grau de conversão e propriedades mecânicas relevantes além de uma estabilidade contra degradação química que é tempo-dependente.

OBJECTIVES: Self-assembling peptide P(11)-4 is amphiphilic and pH-triggered, effective on repairing early enamel carious lesions and dentin remineralization. However, P(11)-4 effects on dentin biomineralization and repair ability remain unexplored. Thus, cytocompatibility and effectiveness of P(11)-4 on inducing mineralization and migration of odontoblast-like cells (MDPC-23) were investigated. METHODS: MDPC-23 were seeded in contact with P(11)-4 (0.5 and 1 μg/ml), Dentin Matrix Protein 1 (DMP1 0.5 and 1 μg/ml) or Calcium hydroxide (Ca(OH)(2) 100 μg/ml) solutions. Cell viability was verified using MTT (n = 6/group). Mineral deposition was tested using Alizarin Red (n = 4/group). Cell migration was assessed by light microscopy (n = 2/group). MTT and Alizarin Red data were compared using Kruskal-Wallis and Mann-Whitney (α=0.01). RESULTS: P(11)-4 (0.5 and 1 μg/ml) and DMP1 (0.5 and 1 μg/ml) resulted the highest cell viability; Ca(OH)(2) presented the lowest. 1 μg/ml DMP1 and 1 μg/ml P(11)-4 promoted the highest mineral deposition. Ca(OH)(2) presented lower values of mineral deposits than DMP1 1 μg/ml (p < 0.01), but similar to P(11)-4 1 μg/ml. P(11)-4 and DMP1 at 0.5 μg/ml induced lesser mineral precipitation than P(11)-4 and DMP1 at 1 μg/ml (p < 0.01), with no difference to Ca(OH)(2). All materials stimulated cell migration, however, lower concentrations of DMP1 and P(11)-4 demonstrated a higher migration potential. CONCLUSION: P(11)-4 did not affect cell viability, induces mineral deposition and MDPC-23 migration like DMP1. CLINICAL SIGNIFICANCE: Self-assembling peptide P(11)-4 does not affect the cell viability and induces mineral deposition comparable to native protein involved in biomineralization. Combined with its ability to bind type I collagen, P(11)-4 is a promising bioinspired molecule that provides native-tissue conditions and foster further studies on its ability to form dentin bridges in pulp-capping strategies.

Made available in DSpace on 2019-10-04T12:42:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-08-20 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) A series of experiments were conducted to characterize a novel restorative material. We explored the effect on biological, physical and chemical properties of glass ionomer cement (GIC) adding-the naturally occurring tt-farnesol (900 mM). Two groups were accomplished for all assays: GIC+tt-farnesol and GIC (control). Biological assays: 1) agar diffusion against some cariogenic bacteria; 2) S. mutans biofilm formation and confocal laser scanning microscopy-CLSM. 3) gtfB, gtfC, gtfD, gbpB, vicR, and covR expression; 4) MTT and microscopic morphology. Physical properties assays: 1) roughness; 2) hardness; 3) compressive strength and 4) diametral tensile strength. Chemical assay: Raman spectroscopy. The adding of tt-farnesol to GIC led to larger zones of inhibition (p0.05). Polysaccharides levels increased over time, similarly over groups (p>0.05). Viable and non-viable S. mutans were seen on the specimens' surface by CLSM but their virulence was not modulated by tt-farnesol. The tt-farnesol increased the HaCaT cell viability without impact on compressive and diametral tensile strength and roughness although the hardness was positively affected (p

(1) Background: The amino acid arginine is now receiving great attention due to its potential anti-caries benefits. The purpose of this in vitro study was to evaluate the shear bond strength (SBS), ultimate tensile strength (UTS), and antimicrobial potential (CFU) of two arginine-containing orthodontic resin cements. (2) Methods: Forty bovine incisors were separated into four groups (n = 10): Orthocem, Orthocem + arginine (2.5 wt%), Transbond XT, and Transbond XT + arginine (2.5 wt%). The brackets were fixed to the flat surface of the enamel, and after 24 h the SBS was evaluated using the universal testing machine (Instron). For the UTS test, hourglass samples (n = 10) were made and tested in a mini-testing machine (OM-100, Odeme). For the antibacterial test (colony forming unit-CFU), six cement discs from each group were made and exposed to Streptococcus mutans UA159 biofilm for 7 days. The microbiological experiment was performed by serial and triplicate dilutions. The data from each test were statistically analyzed using a two-way ANOVA, followed by Tukey’s test (α = 0.05). (3) Results: The enamel SBS mean values of Transbond XT were statistically higher than those of Orthocem, both with and without arginine (p = 0.02033). There was no significant difference in the SBS mean values between the orthodontic resin cements, either with or without arginine (p = 0.29869). The UTS of the Transbond XT was statistically higher than the Orthocem, but the addition of arginine at 2.5 wt% did not influence the UTS for either resin cement. The Orthocem + arginine orthodontic resin cement was able to significantly reduce S. mutans growth, but no difference was observed for the Transbond XT (p = 0.03439). (4) Conclusion: The incorporation of arginine to commercial orthodontic resin cements may be an efficient preventive strategy to reduce bacterial growth without compromising their adhesive and mechanical properties.

Self-assembling peptide P11-4 is amphiphilic and pH-triggered with demonstrated effectivity repairing early carious lesions in enamel. However, P11-4 effects on dentin biomineralization and repair remain unexplored. Thus, cytocompatibility and effectiveness of P11-4 inducing mineralization and migration of odontoblast-like cells (MDPC-23) were investigated. MDPC-23 were seeded in contact with P11-4(0.5µg/ml and 1µg/ml), Dentin Matrix Protein 1 (DMP1 0.5µg/ml and 1 µg/ml) or Calcium hydroxide (Ca(OH)2 100µg/ml) solutions. Cytotoxicity was verified using MTT (n=6/group). Mineralization was tested using Alizarin Red (n=4/group). Cell migration was assessed by light microscopy (n=2/group). MTT and Alizarin Red data were compared using Krus-kal-Wallis and Mann-Whitney (α=0.05). P11-4 (0.5µg/ml and 1µg/ml) and DMP1 (0.5µg/ml and 1µg/ml) presented the highest cytocompatibility; Ca(OH)2 presented the lowest. DMP1 1µg/ml exhibited the highest mineralization ability, with no difference to P11-4 1µg/ml. Ca(OH)2 presented lower values than DMP1 1µg/ml (p

Objective: To evaluate the antibacterial activity of four formulations of calcium hydroxide paste against microorganisms commonly found in infected root canals. Methods: To evaluate antibacterial activity through the agar diffusion method, pastes of calcium hydroxide were made from its pro-analysis form, diffused into four separate vehicles: distilled water, camphorated p-monochlorophenol, propylene glycol and Otosporin®, testing the antimicrobial activity of these on strains of Staphylococcus aureus, Bacillus subtilis and Enterococcus faecalis. After the incubation period, the presence or otherwise of inhibition zones were observed and their sizes in three stages: 24h, 48h and 72h. With this data, the median between the four dishes was obtained and the consequent value was submitted to Kruskal-Wallis nonparametric statistical analysis, with post-tests of Mann-Whitney and Bonferroni correction, at a significance level of 5%. Results: Only pastes with camphorated p-monochlorophenol and Otosporin vehicles caused the formation of significant inhibition zones, with medians of 8.0 mm. Against the strains of Enterococcus faecalis, only pastes with the camphorated p-monochlorophenol vehicle resulted in the formation of significant inhibition zones, with a median of 3.0 mm. Conclusion : Otosporin and CMCP vehicles provide greater antimicrobial potential to calcium hydroxide against the studied bacteria. However, only the Ca(OH)2 and CMCP combination was effective against all the strains, and can thus be regarded as the paste formulation with the greatest antimicrobial effectiveness in this study.

Neste estudo foi avaliado caracteristicas de sorcao e solubilidade e de tenacidade a fratura de compositos com diferentes tipos de carga em comparacao ao novo composito com carga contendo diatomita (Zirconfill). Para os testes foram utilizadas as resinas Zirconfill, Z350 e Mosaic. As analises de sorcao e solubilidade foram feitas conforme a ISO 4049 por meio da confeccao de discos (15x1mm) de cada composito (n=8). Todas as amostras, em todas as analises, foram foto-ativadas por 40s (1200 mW/cm2). Os discos foram secos e pesados ate se obter o peso sem variacao. Foram armazenados em agua destilada por 7 dias e novamente pesados para o teste de sorcao. Em seguida, armazenados em estufa 37 °C ate atingir um peso constante para que fosse usado no teste de solubilidade. A tenacidade a fratura foi avaliada conforme a ISO 13586. As amostras (n=10) foram confeccionadas utilizando matrizes metalicas com um defeito em forma de cunha no centro. Apos a fotoativacao, as amostras foram submetidas ao teste de flexao e os dados incluidos na formula de tenacidade a fratura. Foram aplicados os testes de normalidade dos dados e estatistica descritiva adequada considerando o nivel de significância de 5%. Para o teste de sorcao foi aplicado Kruskal-Wallis e nao houve diferenca entre os grupos. Para solubilidade, foi feita com Anova One-way e a resina Mosaic solubilizou mais que Zirconfill e Z350. Com relacao a tenacidade a fratura, Anova One-way e nao houve diferenca estatistica entre os grupos.

O estudo?in vitro?objetivou?investigar a influencia da incorporacao de diferentes concentracoes de nanotubos de?dioxido de titânio?(n-?TiO2)?nas propriedades fisicas do cimento de ionomero de vidro (CIV).?Ao?Ketac?Molar?EasyMix?foi incorporado concentracoes de?n-TiO2?(0%,?3%; 5%; 7% em peso), sintetizados pelo metodo alcalino (20?nm). O?tempo de reacao de presa inicial e final, apos a aglutinacao do?CIV?foi avaliado apos?90?s?da aglutinacao usando?as agulhas?maior e menor calibre de?Gillmore,?respectivamente?(n=12). Enquanto o?tempo da?perda de?brilho foi?calculado?utilizando um cronometro digital TIMEX.?As avaliacoes foram realizadas seguindo as especificacoes da?ISO 9917-1?e o experimento foi repetido?por duas vezes.?Os dados foram submetidos a ANOVA?e?teste de?Tukey?(?=0,05).? O CIV contendo 7% de TiO2 exibiu o valor mais elevado de tempo de presa inicial (344,16 ± 6,84 s), diferindo estatisticamente do grupo controle (334,25 ± 7,47 s) e do grupo contendo 3% de TiO2 (331,75 ± 7,23 s) (p

Introduction Much advertising in mouthwash is conveyed in all media appealing to the anti-plaque effect and rendering a disservice to the community. Mouth rinses are available over-the-count and differ on their compositions and antimicrobial effectiveness. Objective In this study, we evaluated the antimicrobial activity of 35 widely available mouth rinses against bacterial species involved in initiation of dental biofilm – Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius, and Streptococcus sanguinis. Material and method The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of the evaluated mouth rinses were determined according to the Clinical & Laboratory Standards Institute protocols. Data were submitted to Kruskal-Wallis test and Mann-Whitney post hoc (α=0.05). Result About 70% of the mouth rinses achieved high antibacterial activity and 30%, a low antibacterial activity against all the species tested. The most ineffective mouth rinse showed antibacterial activity (MIC) at 1:1 dilution, while the most effective showed activity even at 1:2048 dilution, which may imply prolonged effect in the mouth. About 51% of mouth rinses showed bactericidal activity, and it was verified that cetylpyridinium chloride or chlorhexidine digluconate containing in the formulation were associated with the highest activity. Conclusion Most - but not all - mouth rinses commercially available are effective in inhibiting in vitro initial colonizers of dental surfaces. Resumo Introdução Muita publicidade sobre enxaguatórios bucais é veiculada em todos os meios de comunicação apelando para o efeito anti-placa e prestando um desserviço à comunidade. Grande quantidade de enxaguatórios bucais está disponível no mercado e estes diferem em suas composições e eficácia antimicrobiana. Objetivo Neste estudo, avaliamos a atividade antimicrobiana de 35 enxaguatórios bucais amplamente disponíveis contra espécies bacterianas envolvidas na iniciação do biofilme dental - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius e Streptococcus sanguinis. Material e método A Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) dos enxaguatórios avaliados foram determinadas de acordo com os protocolos do Clinical & Laboratory Standards Institute. Os dados foram submetidos ao teste Kruskal-Wallis e Mann-Whitney post hoc (α=0,05). Resultado Aproximadamente 70% dos enxaguatórios bucais alcançaram alta atividade antibacteriana e 30%, baixa atividade antibacteriana contra todas as espécies testadas. O enxaguatório bucal mais ineficaz mostrou atividade antibacteriana (CIM) na diluição de 1:1, enquanto a mais eficaz mostrou atividade mesmo na diluição de 1:2048, o que pode implicar em efeito prolongado na boca. Cerca de 51% dos enxaguatórios bucais apresentaram atividade bactericida, e verificou-se que formulações contendo cloreto de cetilpiridíneo ou digluconato de clorexidina estavam associados à maior atividade. Conclusão A maior parte - mas não todos – dos enxaguatórios bucais comercialmente disponíveis são eficazes na inibição de colonizadores iniciais de superfícies dentárias in vitro.

The use of antimicrobial monomers, linked to the polymer chain of resin composites, is an interesting approach to circumvent the effects of bacteria on the dental and material surfaces. In addition, it can likely reduce the incidence of recurrent caries lesions. The aim of this study was to evaluate the effects of a novel Triclosan Methacrylate (TM) monomer, which was developed and incorporated into an experimental resin composite, on Streptococcus mutans (S. mutans) biofilms, focusing on the analyses of vicR, gtfD, gtfC, covR, and gbpB gene expression, cell viability and biofilm characteristics. The contact time between TM-composite and S. mutans down-regulated the gbpB and covR and up-regulated the gtfC gene expression, reduced cell viability and significantly decreased parameters of the structure and characteristics of S. mutans biofilm virulence. The presence of Triclosan Methacrylate monomer causes harmful effects at molecular and cellular levels in S. mutans, implying a reduction in the virulence of those microorganisms.

Orientador: Regina Maria Puppin Rontani Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba Resumo: O objetivo neste estudo foi avaliar a influencia de resina composta experimental, com antimicrobiano na composicao, sobre a expressao genica de Streptococcus mutans em 4 e 24 horas. Tres grupos foram preparados: CE . Grupo controle . Ceramica (IPS Empress Esthetic); RSA . TEGDMA/BISEMA+fotoiniciador+carga; RCA . RSA+Metacrilato de triclosan. Discos (2x6 mm) de cada grupo foram confeccionados e posteriormente mantidos sob luz UV por 15 minutos para descontaminacao em camara de fluxo laminar. Cada disco foi colocado em um poco de uma placa de cultura imerso em 1,5 mL de BHI com 1% de sacarose com inoculo de uma cepa de Streptococcus mutans UA159 e armazenado a 37 ¿C em ambiente enriquecido com 10% de CO2 por 4 e 24 horas. Apos decorridos os tempos, os discos foram removidos dos pocos e as celulas lavadas com 2 mL de solucao salina gelada. Sequentemente transferidas para microtubos de 2 mL e centrifugados a 16000 gF a 4 ¿C por 2 minutos para precipitacao do pellet celular (o pellet foi a unidade experimental do estudo n=5). O pellet foi imediatamente congelado a .80 ¿C para posterior purificacao do RNA. A purificacao do RNA total foi feita utilizando RNeasy Mini Kit (50). O RNA foi em seguida convertido para cDNA com o uso do iScript Transcriptase Reverse e o cDNA foi armazenado a .20 ¿C para posterior analise da expressao genica. As analises da expressao dos genes estudados, gtfC, gtfD, gbpB, vicR e covR, foram feitas utilizando o aparelho Step One Real-Time qPCR com primers especificos para cada gene e as analises normalizadas pela expressao do gene de referencia 16S. Kruskal-Wallis foi utilizado para analise de gtfC em 24 horas com Student-Newman-Keus para comparacao entre os grupos. Os demais genes em 4 e 24 horas foram analisados por ANOVA um fator utilizando Tukey para comparacao entre grupos (¿¿=0,05). Os genes gtfD e vicR apresentaram valores de expressao significativamente menores para a resina com antimicrobiano em relacao aos outros grupos no tempo de 4 horas. Os genes covR e gbpB do grupo da resina com antimicrobiano apresentaram valores de expressao significativamente menores em relacao aos outros grupos para o tempo de 24 horas. O gene gtfC na resina com metacrilato de triclosan, apresentou valores maiores de expressao em relacao aos outros grupos no tempo de 24 horas. Nao houve diferenca nos valores de expressao para nenhum dos genes analisados entre os grupos ceramica e resina sem antimicrobiano. Conclui-se que apenas a resina composta com metacrilato de triclosan foi capaz de alterar a expressao dos genes de Streptococcus mutans analisados nesse estudo Abstract: The aim of this study was to evaluate the influence of experimental antimicrobial-adding composite resin on gene expression of Streptococcus mutans after 4 and 24 hours. Three groups were accomplished for this study: CE ¿Control group - Ceramic (IPS Empress Esthetic); RSA-TEGDMA/BISEMA+fotoinitiators+filler; RCA ¿ RSA+triclosan methacrylate. Discs (2x6 mm) from each group were made and subsequently kept under UV light for 15 minutes for decontamination in a laminar flow hood. Each disc was placed in a well of a culture plate immersed in 1.5 mL of 1% sucrose supplemented BHI broth with an inoculum of Streptococcus mutans UA159 strain and stored at 37 °C in atmosphere enriched with 10% CO2 for 4 or 24 hours. Next, the discs were removed from the wells and the cells washed with 2 mL of cold saline solution and transferred to 2 mL microtubes and centrifuged at 16000 gF at 4 °C for 2 min to cell pellet precipitation (pellet was considered the experimental unit, n=5). The pellet was frozen immediately at ¿80 °C. RNA total purification was performed using RNeasy Mini Kit (50). Then, the RNA was converted to cDNA using the iScript reverse transcriptase and the cDNA was stored at ¿20 °C for subsequent gene expression analysis. The analysis of gtfC, gtfD, gbpB, vicR and covR gene expression were performed using Step One Real-Time qPCR device with specific primers for each gene and analyzes were normalized by expression of 16S reference gene. Kruskal-Wallis test was used to gtfC/24 hours with Student-Newman-Keus for comparison between groups. The remaining genes and 4 or 24h period were analyzed by ANOVA One-way using Tukey for comparison between groups (á=0.05). At 4h analyisis antimicrobial-containing composite resin provided vicR and gtfD gene expression significantly lower than control group. At 24-hour analysis antimicrobial-containing composite resin provided significantly higher expression for gtfC, but the lower expression for covR and gbpB genes than the control group. There was no significant difference in the gene expression values for any of the analyzed genes between the ceramic and resin with no antimcrobial groups. It can be concluded that only the antimicrobial-containing resin composite was able to alter the expression of Streptococcus mutans genes analyzed in this study Mestrado Materiais Dentários Mestre em Materiais Dentários CAPES

Neste estudo avaliou-se a toxicidade de compósito experimental, com monômero Metacrilato de Triclosan (MT), sobre células bacterianas e humanas. Foram confeccionados discos (2x5 mm) de dois compósitos C1 (TEGDMA/BISEMA + carga) e C2 (C1 + MT). Para a viabilidade bacteriana foi utilizada cepa de S. mutans UA159. Os discos foram colocados em placas de cultura de 24 poços, com 2 ml de BHI e inóculo bacteriano, por 24 h. Decorrido o tempo, os discos foram lavados com PBS e a viabilidade celular avaliada por XTT. A solução de XTT foi dispensada sobre os discos, e armazenada em estufa a 37 ºC, com 10% de CO2, por 4 h. Após a incubação, 200 μl da solução foram dispensados em eppendorfs, centrifugados e o sobrenadante transferido para uma placa de 96 poços para leitura das absorbâncias. Para avaliação em células humanas, foram utilizadas células NOK cultivadas em soro fetal bovino 10% a 37 °C. As células (1X105 células/ml) ficaram em contato com os discos por 24 h. Em seguida, as células foram tratadas com reagente MTT e reincubadas por 4 h. Após, 100 μL de álcool isopropílico foram usados para solubilizar o precipitado e permitir as leituras. As absorbâncias, 450nm (XTT) e 560nm (MTT), foram medidas com leitor de ELISA. A análise estatística foi feita com o teste Mann-Whitney (a0.05). Nas análises de XTT, C2 (0,582 ±0,041) reduziu a viabilidade celular (p0,0076) em relação a C1 (0,634 ±0,030). Nas análises de MTT, C1 (88% ±6,77) apresentou maior viabilidade celular (p0,0219) que C2 (70,6 ±7,67). Conclusão: C1 e C2 não foram tóxicos para NOK (viabilidade >50%) e C2 reduz a viabilidade de S. mutans.Palavras-chave: Compósitos. Viabilidade Celular. Antimicrobianos.

Aim: To evaluate the clinical performance of a composite resin (CR) and a resin-modified glass-ionomer cement (RMGIC) for the treatment of abfraction lesions. Methods: Thirty patients with abfraction lesions in at least two premolar teeth were selected and invited to participate in this study. All restorations were made within the same clinical time frame. One tooth was restored with CR Z100TM (3M, St. Paul, MN, USA), and the other was restored with RMGIC VitremerTM (3M). The restorations were assessed immediately and 1, 6 and 12 months after the restoration, using modified US Public Health Service (USPHS) criteria: marginal integrity, marginal discoloration, wear, retention, secondary caries and hypersensitivity. The statistical analysis was based on Friedman ANOVA test and Mann-Whitney test, considering p