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OBJECTIVE: The present in vitro study incorporated niobium oxyhydroxide fillers into an experimental high-viscosity bulk-fill resin composite to improve its mechanical performance and provide it a bioactive potential. METHODOLOGY: Scanning electron microscopy synthesized and characterized 0.5% niobium oxyhydroxide fillers, demonstrating a homogeneous morphology that represented a reinforcement for the feature. Fillers were weighed, gradually added to the experimental resin composite, and homogenized for one minute, forming three groups: BF (experimental high-viscosity bulk-fill resin composite; control), BF0.5 (experimental high-viscosity bulk-fill resin composite modified with 0.5% niobium oxyhydroxide fillers), and BFC (commercial bulk-fill resin composite Beautifil Bulk U, Shofu; positive control). In total, 10 specimens/groups (8 × 2 × 2 mm) underwent flexural strength (FS) tests in a universal testing machine (Instron) (500N). Resin composites were also assessed for Knoop hardness (KH), depth of cure (DoC), degree of conversion (DC), elastic modulus (E), and degree of color change (ΔE). The bioactive potential of the developed resin composite was evaluated after immersing the specimens into a simulated body fluid in vitro solution and assessing them using a Fourier-transformed infrared spectroscope with an attenuated total reflectance accessory. One-way ANOVA, followed by the Tukey's test (p<0.05), determined FS, DC, KH, and ΔE. For DoC, ANOVA was performed, which demonstrated no significant difference between groups (p<0.05). CONCLUSIONS: The high-viscosity bulk-fill resin composite with 0.5% niobium oxyhydroxide fillers showed promising outcomes as reinforcement agents and performed well for bioactive potential, although less predictable than the commercial resin composite with Giomer technology.
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Resinas Compuestas , Niobio , Viscosidad , Ensayo de Materiales , Polimerizacion , Materiales DentalesRESUMEN
Abstract Objective The present in vitro study incorporated niobium oxyhydroxide fillers into an experimental high-viscosity bulk-fill resin composite to improve its mechanical performance and provide it a bioactive potential. Methodology Scanning electron microscopy synthesized and characterized 0.5% niobium oxyhydroxide fillers, demonstrating a homogeneous morphology that represented a reinforcement for the feature. Fillers were weighed, gradually added to the experimental resin composite, and homogenized for one minute, forming three groups: BF (experimental high-viscosity bulk-fill resin composite; control), BF0.5 (experimental high-viscosity bulk-fill resin composite modified with 0.5% niobium oxyhydroxide fillers), and BFC (commercial bulk-fill resin composite Beautifil Bulk U, Shofu; positive control). In total, 10 specimens/groups (8 × 2 × 2 mm) underwent flexural strength (FS) tests in a universal testing machine (Instron) (500N). Resin composites were also assessed for Knoop hardness (KH), depth of cure (DoC), degree of conversion (DC), elastic modulus (E), and degree of color change (ΔE). The bioactive potential of the developed resin composite was evaluated after immersing the specimens into a simulated body fluid in vitro solution and assessing them using a Fourier-transformed infrared spectroscope with an attenuated total reflectance accessory. One-way ANOVA, followed by the Tukey's test (p<0.05), determined FS, DC, KH, and ΔE. For DoC, ANOVA was performed, which demonstrated no significant difference between groups (p<0.05). Conclusions The high-viscosity bulk-fill resin composite with 0.5% niobium oxyhydroxide fillers showed promising outcomes as reinforcement agents and performed well for bioactive potential, although less predictable than the commercial resin composite with Giomer technology.
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Objective: Evaluate a fluoride varnish modified by nanostructures with the bioactive qualities of silica (SiO2) and niobium pentoxide (Nb2O5), testing its remineralizing potential by surface hardness (SH) and energy-dispersive X-ray spectroscopy (EDX). Material and Methods: Bovine enamel specimens (6×4×2mm) were prepared and submitted to a demineralizing/remineralizing process to produce a subsurface caries-like lesion, evaluated by transversal microradiography image (TMR) and subsequently distributed randomly into three groups: fluoride varnish (VZ); fluoride varnish + silica gelatin (VZ-SiO2) and fluoride varnish + niobium nanoparticles (VZ-Nb2O5). The specimens were subjected to a pH-cycling demineralizing/remineralizing process for 7 days at 37ºC. The %SH loss and %SH recovery (after the pH-cycling regimen) were calculated (n=10/group). The Ca/P weight ratio before and after the pH-cycling regimen was evaluated through SEM/EDX. A two-way ANOVA followed by Tukey's test (p<0.05) was performed for hardness and EDX. Results: TMR image showed the formation of an artificial subsurface lesion, and a significant SH increase was observed in the VZ-Nb2O5 group (p<0.05). Regarding the %SHL and %SHR, the VZ-Nb2O5 and VZ-SiO2 were significantly different compared to the VZ group (p<0.001), but VZ-Nb2O5 presented higher values. The Ca/P ratio showed that blocks treated with VZ-SiO2 and VZ-Nb2O5 showed greater ion deposition, particularly in the presence of Nb. Conclusion: The bioactivity of niobium facilitated greater interaction between the enamel and the varnish, leading to a slow release of nanoparticles and a longer-lasting remineralizing effect (AU)
Objetivo: Avaliar um verniz fluoretado modificado por nanoestruturas com a bioatividade da sílica (SiO2) e pentóxido de nióbio (Nb2O5), testando seu potencial remineralizador pela dureza de superfície (SH) e espectroscopia de energia dispersiva de raios-X (EDX). Material e Métodos: Espécimes de esmalte bovino (6×4×2mm) foram preparados e submetidos à desmineralização/remineralização para produzir uma lesão subsuperficial semelhante a cárie, avaliada por imagem de microrradiografia transversal (TMR) sendo distribuída em três grupos: verniz fluoretado (VZ); verniz fluoretado+gelatina de sílica (VZ-SiO2) e verniz fluoretado+nanopartículas de nióbio (VZ-Nb2O5). As amostras foram submetidas à desmineralização/remineralização por ciclagem de pH durante 7 dias a 37°C. A porcentagem de perda e recuperação de SH foram calculadas (n=10/grupo). A relação em peso Ca/P antes e depois da ciclagem foi avaliada através de MEV/EDX. ANOVA a dois critérios seguida do teste de Tukey (p<0,05) foi realizada para dureza e EDX. Resultados: A TMR mostrou a formação de uma lesão subsuperficial e um aumento significativo de SH foi observado no grupo VZ-Nb2O5 (p<0,05). Em relação ao %SHL e %SHR, o VZ-Nb2O5 e o VZ-SiO2 foram significativamente diferentes em relação ao grupo VZ (p<0,001), mas o VZ-Nb2O5 apresentou valores maiores. A relação Ca/P mostrou que os blocos tratados com VZ-SiO2 e VZ-Nb2O5 apresentaram maior deposição de íons, principalmente na presença de Nb. Conclusão: A bioatividade do nióbio facilitou maior interação entre o esmalte e o verniz, levando a uma liberação lenta de nanopartículas e a um efeito remineralizante mais duradouro (AU)
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Remineralización Dental , Operatoria Dental , Nanoestructuras , Fluoruros , NiobioRESUMEN
This in vitro study synthesized hybrid nanofibers embedded in graphene oxide (GO) and incorporated them into experimental resin composite monomers to evaluate their physical-mechanical properties. Inorganic-organic hybrid nanofibers were produced with precursor solutions of 1% wt. GO-filled Poly (d,l-lactide, PLA) fibers and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) characterized the morphology and chemical composition of the spun fibers. Resin composite monomers were developed and a total of 5% nanofibers were incorporated into the experimental materials. Three groups were developed: G1 (control resin monomers), G2 (resin monomers/PLA nanofibers), and G3 (resin monomers/inorganic-organic hybrid nanofibers). Contact angle (n=3), flexural strength (n=22), elastic modulus (n=22), and Knoop hardness (n=6) were evaluated. The mean of the three indentations was obtained for each sample. The normality of data was assessed by QQ Plot with simulated envelopes and analyzed by Welch's method (p<0.05). Overall, SEM images showed the regular shape of nanofibers but were non-aligned. Compositional analysis from EDS (n=6) revealed the presence of carbon and oxygen (present in GO composition) and Si from the functionalization process. The results of contact angle (°) and hardness (Kg/mm2) for each group were as follow, respectively: G1 (59.65±2.90; 37.48±1.86a), G2 (67.99±3.93; 50.56±1.03b) and G3 (62.52±7.40; 67.83±1.01c). The group G3 showed the highest Knoop hardness values (67.83 kg/mm2), and the flexural strength of all groups was adversely affected. The experimental resin composite composed of hybrid nanofibers with GO presented increased hardness values and hydrophilic behavior.
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Grafito , Nanofibras , Nanofibras/química , Resinas Compuestas/química , Poliésteres/química , Ensayo de Materiales , Propiedades de SuperficieRESUMEN
This systematic review provides an update on the effect of nanofibers as reinforcement on resin-based dental materials. A bibliographic search was conducted in MEDLINEPubMed, Embase, Web of Science, Scopus, BVS (LILACS, BBO e IBECS), Cochrane, LIVIVO, and gray literature (BDTD) to identify relevant articles up to May 2021. In vitro studies that evaluated and compared the mechanical properties of nanofibers resin-based composite materials, were eligible. No publication year or language restriction was applied, and methodological quality was assessed using two methods. In a total of 6100 potentially eligible studies, 81 were selected for full-text analysis and 35 were included for qualitative analysis. Of the 35 included studies, a total of 29 studies evaluated the flexural strength (FS) of the materials. These groups were distinguished according to the resin-based materials tested and nanofiber types. Most of the studies evaluated materials composed of glass fibers and demonstrated higher values of FS when compared to resin-based materials without nanofibers. The incorporation of nanofibers into resin-based dental materials improved the mechanical properties compared to resin-based materials without nanofibers, suggesting better performance of these materials in high-stressbearing application areas. Further clinical studies are required to confirm the efficacy of resin-based materials with nanofibers.
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Abstract This in vitro study synthesized hybrid nanofibers embedded in graphene oxide (GO) and incorporated them into experimental resin composite monomers to evaluate their physical-mechanical properties. Inorganic-organic hybrid nanofibers were produced with precursor solutions of 1% wt. GO-filled Poly (d,l-lactide, PLA) fibers and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) characterized the morphology and chemical composition of the spun fibers. Resin composite monomers were developed and a total of 5% nanofibers were incorporated into the experimental materials. Three groups were developed: G1 (control resin monomers), G2 (resin monomers/PLA nanofibers), and G3 (resin monomers/inorganic-organic hybrid nanofibers). Contact angle (n=3), flexural strength (n=22), elastic modulus (n=22), and Knoop hardness (n=6) were evaluated. The mean of the three indentations was obtained for each sample. The normality of data was assessed by QQ Plot with simulated envelopes and analyzed by Welch's method (p<0.05). Overall, SEM images showed the regular shape of nanofibers but were non-aligned. Compositional analysis from EDS (n=6) revealed the presence of carbon and oxygen (present in GO composition) and Si from the functionalization process. The results of contact angle (°) and hardness (Kg/mm2) for each group were as follow, respectively: G1 (59.65±2.90; 37.48±1.86a), G2 (67.99±3.93; 50.56±1.03b) and G3 (62.52±7.40; 67.83±1.01c). The group G3 showed the highest Knoop hardness values (67.83 kg/mm2), and the flexural strength of all groups was adversely affected. The experimental resin composite composed of hybrid nanofibers with GO presented increased hardness values and hydrophilic behavior.
Resumo Este estudo in vitro sintetizou nanofibras híbridas embebidas em óxido de grafeno (GO), incorporando-as à uma resina composta experimental de monômeros para avaliar suas propriedades físico-mecânicas. Nanofibras híbridas inorgânica-orgânicas foram produzidas com soluções precursoras de fibras poli (d, l-lactídeo, PLA) preenchidas com GO a 1% em peso e microscopia eletrônica de varredura (MEV) e espectroscopia de raio-X de energia dispersiva (EDS) caracterizaram a morfologia e composição química das fibras. Monômeros de resina composta foram desenvolvidos e um total de 5% de nanofibras foi incorporado aos materiais experimentais. Três grupos foram desenvolvidos: G1 (monômeros de resina controle), G2 (monômeros de resina/ nanofibras de PLA) e G3 (monômeros de resina/nanofibras híbridas inorgânico-orgânicas). Ângulo de contato (n=3), resistência à flexão (n=22), módulo de elasticidade (n=22) e dureza Knoop (n=6) foram avaliados. A média das três endentações foi obtida para cada amostra. A normalidade dos dados foi avaliada pelo QQ Plot com envelopes simulados e analisada pelo método de Welch (p<0,05). No geral, as imagens de MEV mostraram forma regular de nanofibras, mas não alinhadas. A análise composicional de EDS (n=6) revelou a presença de carbono e oxigênio (presentes na composição do GO) e Si resultante do processo de funcionalização. Os resultados do ângulo de contato (°) e dureza (Kg/mm2) para cada grupo foram os seguintes, respectivamente: G1 (59,65±2,90; 37,48±1,86a), G2 (67,99±3,93; 50,56±1,03b) e G3 (62,52±7,40; 67,83±1,01c). G3 apresentou os maiores valores de dureza Knoop (67,83 kg/mm2), e a resistência à flexão de todos os grupos foi prejudicada. A resina composta experimental composta por nanofibras híbridas com GO apresentou maiores valores de dureza e comportamento hidrofílico.
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O presente trabalho tem como objetivo realizar uma revisão de literatura e discutir os mais atuais conceitos sobre abordagem conservadora de lesões cariosas profundas, facilitando o manejo clínico. Para que essa abordagem conservadora seja implementada, é imprescindível que se conheça a composição estrutural e funcional do biofilme para, assim, entender a evolução da doença cárie que acomete a estrutura dentária. No entanto, quando se trata de um dente com lesão de cárie ativa com grande comprometimento de esmalte e dentina, procedimentos operatórios mais invasivos e restauradores podem ser necessários, mesmo que fundamentados na maior preservação possível de estrutura dentária. As evidências mais atuais encontradas na literatura recomendam a remoção seletiva do tecido cariado que consiste na dentina infectada, ou seja, clinicamente amolecida, e restauração definitiva na mesma sessão. Portanto, desde que o dente apresente vitalidade pulpar clinicamente confirmada, acredita-se que a preservação estratégica da dentina, poderá aumentar as chances de sucesso no tratamento, evitando possível exposição da polpa dentária. Adicionalmente, ao optar por práticas conservadoras no contexto da Odontologia de mínima intervenção, resultará em um significativo aumento na longevidade das restaurações sempre associando promoção de saúde ao paciente(AU)
This paper aims to conduct a literature review and discuss the most current concepts on conservative approach to deep carious lesions in permanent posterior teeth, facilitating clinical management. For this conservative approach to be implemented, it is essential to know the structural and functional composition of the biofilm in order to understand the evolution of the caries disease that affects the dental structure. However, when it comes to a tooth with an active caries lesion with major enamel and dentin compromise, more invasive and restorative surgical procedures may be necessary, even if based on the greatest possible preservation of the dental structure. The most current findings in the literature recommend the selective removal of carious tissue consisting of infected dentin, that is, clinically softened, and definitive restoration in the same session. Therefore, as long as the tooth has clinically confirmed pulp vitality, it is believed that the strategic preservation of dentin may increase the chances of successful treatment, avoiding possible exposure of the dental pulp. Additionally, when opting for conservative practices in the context of Minimally Invasive Dentistry, it will result in a significant increase in the longevity of restorations, always associating health promotion to the patient(AU)
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Caries Dental , Caries Dental/terapia , Esmalte Dental , Placa Dental , Restauración Dental Permanente , DentinaRESUMEN
This in vitro study synthetized hybrid composite nanoparticles of graphene oxide (GO) and montmorillonite MMt (GO-MMt) by ultrasound treatments. Samples were characterized by X-ray diffraction, FT-Raman, FTIR, TEM and SEM. The effect of their incorporation (0.3% and 0.5%) on the mechanical properties in a resin-based composite (RBC) and their bioactivity potential were evaluated. The specimens were characterized by evaluating their 3-point flexural strength (n = 6), modulus of elasticity (n = 6), degree of conversion (n = 6), microhardness (n = 6), contact angle (n = 3) and SEM analysis (n = 3). In vitro test in SBF were conducted in the RBCs modified by the hybrid. Overall, the synthetized hybrid composite demonstrated that GO was intercalated with MMt, showing a more stable compound. ANOVA and Tukey test showed that RBC + 0.3% GO-MMt demonstrated superior values of flexural strength, followed by RBC + 0.5% GO-MMt (p < 0.05) and both materials showed higher values of microhardness. All groups presented a contact angle below 90°, characterizing hydrophilic materials. RBCs modified by the hybrid showed Ca and P deposition after 14 days in SBF. In conclusion, RBCs composed by the hybrid showed promising results in terms of mechanical properties and bioactive potential, extending the application of GO in dental materials.
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Bentonita , Grafito , Resinas Compuestas , Grafito/farmacología , Ensayo de Materiales , Propiedades de SuperficieRESUMEN
This study evaluated the effect of the material thickness on shrinkage stress and bottom-to-top hardness ratio of conventional and bulk-fill composites. Six commercial composites were selected based on their different technologies: Two conventional (C1, C2), two high-viscosity bulk-fill (HVB1, HVB2), and two low-viscosity bulk-fill (LVB1, LVB2). Shrinkage stress was analyzed for five specimens with 2 mm thickness (C-factor 0.75 and volume 24 mm3 ) and five specimens with 4 mm thickness (C-factor 0.375 and volume 48 mm3 ) for 300 s in a universal testing machine. Bottom-to-top hardness ratio values were obtained from Knoop microhardness measurements in specimens with 2- and 4-mm thickness (n = 5). Thickness increase resulted in significantly higher shrinkage stress for all materials with the exception of HVB2 and LVB1. C1, C2, HVB2, and LVB1 showed lower bottom-to-top hardness ratios at 4 mm than at 2 mm. Only LVB2 presented a bottom-to-top hardness ratio lower than 80% at 2 mm, while HVB1 surpassed this threshold at 4 mm of depth. The results suggest that the increase of composite thickness affected the shrinkage stress values. Also, thickness increase resulted in lower bottom-to-top hardness ratio. HVB1 showed better behavior than other bulk-fill materials, with low stress and adequate bottom-to-top hardness ratio at 4 mm thickness.
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Resinas Compuestas , Dureza , Ensayo de Materiales , Polimerizacion , Propiedades de SuperficieRESUMEN
STATEMENT OF PROBLEM: Information related to the optical and surface properties, including health compatibility, surface roughness, and esthetics, of 3D-printed dental materials is scarce. PURPOSE: The purpose of this in vitro study was to compare the physical and surface properties of a 3D-printed resin with those of materials used for interim restorations. MATERIAL AND METHODS: A 3D-printed resin (PR) (NextDent C&B MFH; 3D Systems), an autopolymerizing interim material (BA) (Protemp 4; 3M ESPE), and a composite resin (Z350) (Filtek Z350XT; 3M ESPE) were tested for degree of color change (ΔE) (n=7) at different timepoints-24 hours after polishing/baseline (P0), 8 days after polishing (P1), and after artificial aging in water at 60 °C for 24 hours (P2)-by using a CIELab-based colorimeter; flexural strength (σ) (n=10) with a 3-point bend test; Knoop hardness (H) (n=8); and surface roughness (Ra) (n=7) with a profilometer. All specimens were polished 24 hours after polymerization, except for the additional group for surface roughness (BA) without polishing (BANP). A statistical analysis was performed by using 2-way repeated-measures ANOVA followed by the Fischer test for ΔE and 1-way ANOVA followed by the Fisher test for microhardness and surface roughness (α=.05). RESULTS: The Z350 showed the highest values for σ and H, followed by PR. BA showed the lowest results for both tests (P<.05). Considering roughness, the Z350 showed similar values to those of BA but lower than PR; PR showed similar roughness when compared with BA. PR showed the highest color variation among the groups at all timepoints, followed by BA. The Z350 was the most color stable material at all timepoints. CONCLUSIONS: The 3D-printed composite resin had adequate mechanical and surface properties for an interim restorative material. It has the potential to be a low-cost workflow in dentistry, although its color stability could be a concern for long-term use.
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Pulido Dental , Estética Dental , Color , Resinas Compuestas , Ensayo de Materiales , Impresión Tridimensional , Propiedades de Superficie , Flujo de TrabajoRESUMEN
Objective: multidisciplinary treatment has become increasingly common in dental offices and this treatment strategy is based on the achievement of a healthy, harmonious, and pleasant smile. In addition, the development of new ceramic systems and the possibility of making indirect restorations with a low thickness, such as laminates veneers, allowed combining highly satisfactory aesthetic properties, preserving the dental structure through minimally Invasive technique. Case report: this paper describes a multidisciplinary approach involving periodontics and restorative dentistry for the successful, functional, and aesthetic treatment in an adult patient. The digital smile design was performed as a guide to plan the clinical case considering factors such as tooth inclination and position, golden proportion, tooth size and shape. Discussion: based on these concepts, the present work reports, through a clinical case, the restoration of aesthetics and function with ceramic laminates veneers in lithium disilicate, in the case of anatomical correction and diastema closure. Conclusion: overall, the multidisciplinary treatment plan demonstrated to have greater advantages both for the aesthetics and function of the patient, as well as for the work team. During the 24-month follow-up, this case presented great functional and aesthetics results. (AU)
Introdução: o tratamento multidisciplinar tornou-se cada vez mais comum nos consultórios odontológicos, sendo uma estratégia baseada no tratamento da obtenção de um sorriso saudável, harmonioso e agradável. Além disso, o desenvolvimento de novos sistemas cerâmicos e a possibilidade de fazer restaurações indiretas com baixa espessura, como facetas laminadas, permitiram combinar propriedades estéticas altamente satisfatórias, preservando a estrutura dentária com o mínimo desgaste. Caso clínico: este artigo descreve uma abordagem multidisciplinar envolvendo Periodontia e Odontologia restauradora para um tratamento funcional e estético em um paciente adulto. O desenho digital do sorriso foi realizado como um guia para planejar o caso clínico, considerando fatores como inclinação e posição do dente, proporção áurea, tamanho e formato do dente. Discussão: com base nesses conceitos, o presente trabalho relata, através de um caso clínico, a restauração estética e funcional com laminados cerâmicos em dissilicato de lítio para correção anatômica e fechamento de diastemas. Conclusão: em geral, o plano de tratamento multidisciplinar demonstrou ter maiores vantagens tanto para a estética e função do paciente, quanto para a equipe de trabalho. Durante os 24 meses de acompanhamento, esse caso apresentou ótimos resultados funcionais e estéticos. (AU)
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Coronas con Frente Estético , Estética DentalRESUMEN
This study aimed to evaluate the polymerization properties of bulk-fill materials (low and high-viscosity) by using high-intensity continuous light and intermittent photo-activation in terms of polymerization shrinkage stress and degree of conversion (DC). The following Bulk-fill and Conventional nanofilled resin composites were evaluated: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) and Filtek Bulk Fill Posterior (3M/ESPE). A LED device (DB 685, Dabi Atlante) was used for both protocols: continuous uniform and intermittent photo-activation (light-on and light-off cycles) with identical radiant exposure (14 J/cm2). The polymerization shrinkage stress (n=6) was evaluated by inserting a single increment of 12 mm3 between two stainless steel plates (6×2 mm) adapted to a Universal Testing Machine (UTM), at different times. Measurements were recorded after photo-activation. The degree of conversion was evaluated by Fourier transformed infrared spectroscope (FTIR) with an attenuated total reflectance (ATR) accessory (n=5). Data were analyzed by three-way ANOVA and Tukey's HSD (α=0.05) tests. Bulk Fill Posterior presented higher shrinkage stress values when photo-activated with the intermittent technique (p<0.05). The intermittent photo-activation increased the degree of conversion for the low-viscosity bulk-fills (p<0.05). Therefore, the use of modulated photo-activation (intermittent) must be indicated with caution since its use can influence the shrinkage stress and degree of conversion of composites, which varies according to the resin formulations.
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Resinas Compuestas , Ensayo de Materiales , Polimerizacion , ViscosidadRESUMEN
Even with the technical-scientific advance in Dentistry, it is still seen as a profession that causes anxiety in children and adults. Therefore, in addition to the technical knowledge, the dental surgeon must have different strategies in the management and conduct of this situation once anxiety if aggravated can become pathological and interfere in the patient's oral health and his or her quality of life. Thus, the present study was conducted in order to realize the main aspects of dental anxiety, aiming to improve patient-dentist relationship, avoiding the onset of phobic disorders. This is an integrative review of the literature, using the Lilacs and SciELO databases with the descriptors anxiety, phobia and dentist verified individually and later they were crossed with AND operator with search period from 2000 to 2019, articles in Portuguese and in fulltext. The exclusion criteria were: thesis, books, final paper and dissertations. 20 articles were identified which showed that anxiety directly interferes with the effectiveness of treatment in different age groups. Priority should be given to communication between the dental surgeon and his or her patient, to recognize possible causes of discomfort. In addition, it is necessary to carry out more studies because there are differences in the literature concerning the interference of social and economic factors and schooling levels in the anxiety development. (AU).
Mesmo com o avanço técnico-científico na Odontologia, esta ainda é vista como uma profissão que provoca ansiedade em crianças e adultos. Dessa forma, além do conhecimento técnico, o cirurgião-dentista deve possuir estratégias diferenciadas no manejo e na conduta perante esta situação, uma vez que, se agravada, a ansiedade pode torna-se patológica e interferir na saúde bucal do paciente, afetando diretamente sua qualidade de vida. Assim, o presente estudo foi conduzido com intuito de perceber os principais aspectos da ansiedade odontológica, visando aperfeiçoar as relações paciente-dentista, evitando o desencadeamento de transtornos fóbicos. Trata-se de uma revisão integrativa da literatura, utilizando as bases de dados Lilacs e Scielo com os descritores: medo, fobia e dentista, verificados individualamente e posteriormente feito cruzamenento com AND, com período de busca de 2000 a 2019, artigos em portugues e na íntegra. Os critérios de exclusão foram: teses, livros, trabalhos de conclusão de cursos e dissertações. Foram identificados 20 artigos que evidenciaram que a ansiedade interfere diretamente na efetividade do tratamento em diferentes faixas etárias, devendo-se priorizar a comunicação entre o cirurgião-dentista e seu paciente, para reconhecer possíveis causas de desconforto. Porém, é necessário realizar mais estudos devido as divergências na literatura referente a interferência de fatores sociais, econômicos e níveis de escolaridade, no desenvolvimento da ansiedade. (AU)
RESUMEN
Graphene and its derivatives, such as graphene oxide, represent the greatest potential materials in terms of biomaterials due to their excellent physical-chemical and biological properties. Thus, the present study has developed an integrative literature review in order to evaluate the capacity of graphene oxide to replace metal biomaterials currently used in Dentistry. For this purpose, LILACS, SciELO and PubMED databases were evaluated, with the following descriptors: graphene, biomaterials and Odontology, adapted for each database used. Firstly, the descriptors were searched separately and, later, the Boolean operator AND was used to define a search strategy. The articles were selected according to the following inclusion criteria: articles in Portuguese, English and Spanish, published and indexed in the databases, in the last ten years, with texts available in full and regarding the topic under study. A total of 14 scientific papers were found and 10 of them were selected for this review. After the critical reading of each article, it was possible to observe that graphene and its derivates present great biocompatibility, excellent mechanical, electrical and thermic properties, high flexibility, low density and a huge potential to be explored in health science. It is also important to highlight its potential application as a coating of metal biomaterials. (AU)
O grafeno e seus derivados, como o óxido de grafeno, representam atualmente o maior potencial em termos de biomateriais, devido às suas excelentes propriedades físico-químicas e de biocompatibilidade. Assim, o presente estudo teve como premissa conduzir uma revisão integrativa da literatura de modo a verificar a capacidade do óxido de grafeno em substituir os biomateriais metálicos atualmente utilizados na Odontologia. Para isto, foram utilizadas as bases de dados Lilacs, SciELO e Pubmed, com os seguintes descritores: grafeno, biomateriais e Odontologia, adaptados para cada base de dados utilizada. Primeiramente, os descritores foram pesquisados isoladamente e, posteriormente, o operador booleano AND foi utilizado de modo a definir uma estratégia de busca. Os artigos foram selecionados de acordo com os critérios de inclusão: artigos em Português, Inglês e Espanhol, publicados e indexados nas referidas bases de dados, nos últimos dez anos, com texto disponível na íntegra e que retratassem a temática em estudo. Foram encontrados um total de 14 artigos científicos e, dez destes artigos foram selecionados para compor a revisão. A partir da leitura crítica de cada artigo, foi possível observar que o grafeno e seus derivados apresentam uma alta biocompatibilidade, notáveis propriedades mecânicas, elétricas e térmicas, alta flexibilidade, baixa densidade de massa e um enorme potencial a ser explorado para beneficiar a área da saúde. Deve-se, também, destacar sua potencial aplicação como revestimento de materiais metálicos implantáveis. (AU)
RESUMEN
Abstract This study aimed to evaluate the polymerization properties of bulk-fill materials (low and high-viscosity) by using high-intensity continuous light and intermittent photo-activation in terms of polymerization shrinkage stress and degree of conversion (DC). The following Bulk-fill and Conventional nanofilled resin composites were evaluated: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) and Filtek Bulk Fill Posterior (3M/ESPE). A LED device (DB 685, Dabi Atlante) was used for both protocols: continuous uniform and intermittent photo-activation (light-on and light-off cycles) with identical radiant exposure (14 J/cm2). The polymerization shrinkage stress (n=6) was evaluated by inserting a single increment of 12 mm3 between two stainless steel plates (6×2 mm) adapted to a Universal Testing Machine (UTM), at different times. Measurements were recorded after photo-activation. The degree of conversion was evaluated by Fourier transformed infrared spectroscope (FTIR) with an attenuated total reflectance (ATR) accessory (n=5). Data were analyzed by three-way ANOVA and Tukey's HSD (α=0.05) tests. Bulk Fill Posterior presented higher shrinkage stress values when photo-activated with the intermittent technique (p<0.05). The intermittent photo-activation increased the degree of conversion for the low-viscosity bulk-fills (p<0.05). Therefore, the use of modulated photo-activation (intermittent) must be indicated with caution since its use can influence the shrinkage stress and degree of conversion of composites, which varies according to the resin formulations.
Resumo O presente estudo teve como objetivo avaliar as propriedades de polimerização de materiais bulk-fill (baixa e alta viscosidade) utilizando luz contínua de alta intensidade e fotoativação intermitente em relação ao estresse de contração de polimerização e grau de conversão (DC). As seguintes resinas compostas Bulk-fill e nanohíbridas convencionais foram avaliadas: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) e Filtek Bulk Fill Posterior (3M/ESPE). Um dispositivo de LED (DB 685, Dabi Atlante) foi utilizado nos dois protocolos: fotoativação contínua e intermitente contínua (ciclos de liga e desliga) com exposição idêntica (14 J/cm2). A tensão de contração de polimerização (n=6) foi avaliada através da inserção de um incremento único de 12 mm3 entre duas placas de aço inoxidável (6×2 mm) adaptadas a uma Máquina de Ensaio Universal (UTM), em tempos diferentes. As medições foram registradas após a fotoativação. O grau de conversão foi avaliado por FTIR-ATR (n=5). Os dados foram analisados pelos testes ANOVA a três fatores e teste de Tukey (α=0,05). A resina Bulk Fill Posterior apresentou maiores valores de tensão de contração quando fotoativadas com a técnica intermitente (p<0,05). A fotoativação intermitente aumentou o grau de conversão nas resinas bulk-fill de baixa viscosidade (p<0,05). Portanto, o uso de fotoativação modulada (intermitente) deve ser indicado com cautela, uma vez que seu uso pode influenciar a tensão de contração e o grau de conversão dos compósitos, o que varia de acordo com as formulações da resina.
Asunto(s)
Ensayo de Materiales , Resinas Compuestas , Viscosidad , PolimerizacionRESUMEN
We assessed the effect of a new coating material based on resin-modified glass-ionomer with calcium (Ca) in inhibiting the demineralization of underlying and adjacent areas surrounding caries-like lesions in enamel. The measures used were surface hardness (SH) and cross-sectional hardness (CSH). Thirty-six bovine enamel specimens (3 × 6 × 2 mm) were randomly allocated into three groups (n = 12): No treatment (NT); resin-modified glass-ionomer with Ca (Clinpro XT Varnish, 3M ESPE) (CL), and fluoride varnish (Duraphat, Colgate) (DU). The specimens were subjected to alternated immersions in demineralizing (6 h) and remineralizing solutions (18 h) for 7 days. SH measurements were conducted at standard distances of 150, 300, and 450 µm from the treatment area. CSH evaluated the mean hardness profile over the depth of the enamel surface and at standard distances from the materials. The energy-dispersive X-ray spectroscopy analysis was conducted to evaluate the demineralization bands created on the sublayer by % of calcium (Ca), phosphorus (P), and fluoride (F). Ca/P weight ratio was also calculated. Based on SH and CSH measurements, there was no difference between groups at the distances 150 µm (p = 0.882), 300 µm (p = 0.995), and 450 µm (p = 0.998). Up to 50 µm depth (at 150 µm from the treatment area), CL showed better performance than DU ( p< 0.05). NT presented higher loss of Ca and P than CL and DU (p < 0.05). There was no significant difference in the % of F ion among the three groups. The new coating material was similar to F varnish in attenuating enamel demineralization.
Asunto(s)
Calcio/química , Esmalte Dental/efectos de los fármacos , Cementos de Ionómero Vítreo/química , Cementos de Resina/química , Desmineralización Dental/prevención & control , Animales , Cariostáticos/química , Bovinos , Fluoruros Tópicos/química , Pruebas de Dureza , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Distribución Aleatoria , Valores de Referencia , Reproducibilidad de los Resultados , Fluoruro de Sodio/química , Espectrometría por Rayos X , Propiedades de Superficie/efectos de los fármacos , Factores de TiempoRESUMEN
Abstract We assessed the effect of a new coating material based on resin-modified glass-ionomer with calcium (Ca) in inhibiting the demineralization of underlying and adjacent areas surrounding caries-like lesions in enamel. The measures used were surface hardness (SH) and cross-sectional hardness (CSH). Thirty-six bovine enamel specimens (3 × 6 × 2 mm) were randomly allocated into three groups (n = 12): No treatment (NT); resin-modified glass-ionomer with Ca (Clinpro XT Varnish, 3M ESPE) (CL), and fluoride varnish (Duraphat, Colgate) (DU). The specimens were subjected to alternated immersions in demineralizing (6 h) and remineralizing solutions (18 h) for 7 days. SH measurements were conducted at standard distances of 150, 300, and 450 µm from the treatment area. CSH evaluated the mean hardness profile over the depth of the enamel surface and at standard distances from the materials. The energy-dispersive X-ray spectroscopy analysis was conducted to evaluate the demineralization bands created on the sublayer by % of calcium (Ca), phosphorus (P), and fluoride (F). Ca/P weight ratio was also calculated. Based on SH and CSH measurements, there was no difference between groups at the distances 150 µm (p = 0.882), 300 µm (p = 0.995), and 450 µm (p = 0.998). Up to 50 µm depth (at 150 µm from the treatment area), CL showed better performance than DU ( p< 0.05). NT presented higher loss of Ca and P than CL and DU (p < 0.05). There was no significant difference in the % of F ion among the three groups. The new coating material was similar to F varnish in attenuating enamel demineralization.
Asunto(s)
Animales , Bovinos , Calcio/química , Cementos de Resina/química , Esmalte Dental/efectos de los fármacos , Cementos de Ionómero Vítreo/química , Valores de Referencia , Fluoruro de Sodio/química , Espectrometría por Rayos X , Propiedades de Superficie/efectos de los fármacos , Factores de Tiempo , Ensayo de Materiales , Cariostáticos/química , Distribución Aleatoria , Fluoruros Tópicos/química , Reproducibilidad de los Resultados , Desmineralización Dental/prevención & control , Pruebas de Dureza , Concentración de Iones de HidrógenoRESUMEN
This study evaluated the effect of adding the hydrophobic monomer 1,12 dodecanediol dimethacrylate (DDDMA) to experimental sealants with and without thermocycling on degree of conversion (DC), water sorption (WS), water solubility (WSB), color stability (ΔE), and micro-shear bond strength (µSBS). Five experimental and one commercially available sealant (Bisco - BIS) were tested. The experimental sealants were formulated by mixing different percentages of DDDMA monomers and urethane dimethacrylate (UDMA). The photoinitiator system was composed by camphorquinone (CQ) and tertiary amine 4-ethyl benzoate dimetilamiono (EDBA). Ethanol was used as a solvent. The experimental groups were named sequentially according to the monomeric content (DDDMA/UDMA): S40/40 (40/40), S50/30 (50/30), S60/20 (60/20), S70/10 (70/10) and S80/0 (80/0). Data were analyzed separately by one-way ANOVA, followed by Tukey's test (p<0.05). The values of DC ranged from 94.59% (S40/40) to 54.02% (S80/10). BIS showed the highest WS value (p<0.05) and S40/40, S50/30, S60/20 and S80/0 showed the lowest WS values of all tested sealants. WSB values ranged from 7.88 µg/mm3 (BIS) to 13.27 µg/mm3 (S70/10). The highest ΔE value was 11.05±2.88 for BIS and the highest µSBS value was found for S60/20. No significant difference was observed in bond strength between sealants and bovine enamel after thermocycling. Adding DDDMA to the composition of surface sealants can improve its performance, once the monomer increased the degree of conversion and the color stability.
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Resinas Compuestas/química , Metacrilatos/química , Ácidos Polimetacrílicos/química , Poliuretanos/química , Análisis de Varianza , Animales , Alcanfor/análogos & derivados , Alcanfor/química , Bovinos , Color , Recubrimiento Dental Adhesivo/métodos , Esmalte Dental/química , Esmalte Dental/efectos de los fármacos , Etanol/química , Etilenodiaminas/química , Ensayo de Materiales , Transición de Fase/efectos de los fármacos , Polimerizacion , Valores de Referencia , Reproducibilidad de los Resultados , Resistencia al Corte , Solubilidad , Propiedades de Superficie , Temperatura , Factores de Tiempo , Agua/químicaRESUMEN
OBJECTIVES: Post-radiation dental lesions affect mainly the cervical area of the tooth. Until now, there are quite few evidences regarding the effects of radiation exposure on root dentin breakdown. To better understand this effect, we used human root dentin specimens obtained from third molars from similarly aged individuals. MATERIALS AND METHODS: Twenty specimens were analyzed by the surface hardness (SH), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) to evaluate the baseline properties of their root dentin. Other six human teeth were prepared and analyzed by scanning electron microscopy (SEM). Then the specimens were randomly distributed between two groups (n = 13 per group) and irradiated with a total dose of 55 or 70 Gy in a linear accelerator. The percentage of EDX and surface hardness loss (%SHL) were determined based on measurements before and after irradiation. The specimens were also analyzed after irradiation by SEM and XRD. The Ca/P weight ratio was calculated. RESULTS: Based on SEM analysis, radiation exposure induced dehydration of the dentin. The Ca/P weight ratio decreased (p = 0.0045). The %SHL of specimens irradiated with 70 Gy was higher than that of the 55-Gy group (p < 0.05), although even the lower dose induced root dentin breakdown. CONCLUSIONS: Overall, we can state that radiation exposure changes the composition and structure of human root dentin, which detrimentally affect its hardness. CLINICAL RELEVANCE: The changes reported herein might influence the selection of the dental materials and will bring new knowledge in this field to prevent radiation-related caries in root dentin.
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Dentina/efectos de la radiación , Raíz del Diente/efectos de la radiación , Dentina/química , Dureza , Humanos , Técnicas In Vitro , Microscopía Electrónica de Rastreo , Tercer Molar , Espectrometría por Rayos X , Difracción de Rayos XRESUMEN
PURPOSE: This in vitro study was conducted in two regimens hypothesizing that high-fluoride (F) toothpaste (5,000 µg F/g) with or without functionalized tri-calcium phosphate (f TCP) would provide additional protection against (1) root caries development and (2) progression. For both regimens, bovine root dentin specimens were used. METHODS: In regimen 1, 60 specimens were subjected daily to alternate immersions between demineralizing and remineralizing solutions for 7 days. The specimens were randomly distributed into four treatment groups (n=15) : non-F toothpaste; Colgate Total 12 (CT) (1,450 µg F/g); Colgate Prevident (CP) (5,000 µg F/g); and Clinpro 5000 (CL) (5,000 µg F/g) associated with (f TCP), and treated with toothpastes/water slurries (1:3 w/w) (5 minutes), twice a day. In regimen 2, the efficacy of the toothpastes to inhibit the progression of the developed lesions was assessed, using the previously described pH-cycling model without additional treatment. The response variables were based on the percentage of surface hardness change (ΔSH), cross-sectional hardness (ΔCSH), mineral content/lesion depth by transversal microradiography (TMR) and the alkali-soluble F uptake. RESULTS: Both high-F toothpastes reduced initial dentin demineralization and increased the F uptake compared to non-F and conventional toothpastes (P< 0.05). In terms of caries lesion progression, all tested toothpastes were able to promote this protection. CLINICAL SIGNIFICANCE: High-F toothpastes, regardless of the presence of f TCP, were more effective than conventional F toothpaste in inhibiting initial root dentin demineralization.