The restorative procedure in posterior teeth involves clinical steps related to professional skill, especially when using the incremental technique, which may fail in the long term. A recent alternative is bulk-fill resins, which can reduce polymerization shrinkage, decreasing clinical problems such as marginal leakage, secondary caries, and fracture. This scientific study aims to report a clinical case using bulk-fill resin with an occlusal matrix. As determined in the treatment plan, an acrylic resin matrix was produced to establish an improved oral and aesthetic rehabilitation of the right mandibular first molar, which presented a carious lesion with dentin involvement. The occlusal matrix is a simple technique that maintains the original dental anatomy, showing satisfactory results regarding function and aesthetic rehabilitation.
RESUMOO objetivo deste trabalho é avaliar a influência do tratamento criogênico sobre a usinabilidade do aço rolamento ABNT 52100 temperado e revenido para uma dureza média entre 64 e 65 HRC. Testes de torneamento contínuo a seco foram realizados com ferramentas de corte de alumina mista. Além da influência do tratamento criogênico, o efeito da velocidade de corte e do avanço sobre a vida da ferramenta e acabamento da superfície usinada foi investigado. Não foram encontradas diferenças significativas entre os valores de microdureza das amostras tratadas criogenicamente por 4 e 24 horas e, de uma maneira geral, a amostra tratada por 24 horas apresentou menor rugosidade e propiciou vida mais longa à ferramenta de corte. Finalmente, os índices S bi e S ci indicam que o aço ABNT 52100 tratado por criogenia em 24h apresenta notáveis resultados para aplicações de deslizamento e retenção de filmes lubrificantes.Palavras-chaves: torneamento, aço temperado, tratamento criogênico, ferramenta cerâmica.The effect of the cryogenic treatment on the machinability of hardened AISI 52100 bearing steel ABSTRACT This paper is focused on the influence of the cryogenic treatment on the machinability of hardened and quenched AISI 52100 bearing steel (average hardness of 64 -65 HRC) when turning with mixed alumina tools. The effect of cutting speed, feed rate and time for cryogenic treatment on tool life and surface finish was investigated. The microhardness values of the samples were not drastically affected by the duration of the cryogenic treatment. In general, the samples subjected to cryogenic treatment for 24 hours presented lower roughness values and promoted longer tool lives. Additionally, noteworthy values for the S bi and S ci parameters were obtained after turning the samples treated cryogenically for 24 hours.Keywords: hard turning, cryogenic treatment, ceramic tool. INTRODUÇÃONas últimas décadas, um interesse especial tem sido demonstrado pelo efeito de baixas temperaturas no tratamento térmico dos aços. Alguns trabalhos indicam que, dentre outros benefícios, a vida das ferramentas de corte pode aumentar significativamente após estas serem submetidas ao tratamento térmico subzero. Diferentemente dos revestimentos, o tratamento criogênico é aplicado em todo o volume e não apenas superficialmente, o que garante a manutenção de suas propriedades ao longo de toda vida da ferramenta. Porém, a falta de consenso sobre os fenômenos metalúrgicos envolvidos no aumento da resistência ao desgaste e alguns resultados contraditórios encontrados na literatura colocam em dúvida os reais benefícios deste tratamento.
BackgroundTeriparatide is a synthetic drug similar than PTH (parathyroid hormone), which is currently used as long-term treatment option for patients with bone chronic diseases, as osteoporosis; and this drug can interfere in a positive way in orthodontic movement. Objectives: The medical literature was assessed in the present systematic review in order to determine the level of scientific evidence supporting the influence of teriparatide in induced tooth movement.Material and MethodsThe PRISMA Checklist was followed in this systematic review. Four electronic databases (PubMed; Scopus; ScienceDirect; OpenGrey) were searched without implementing restrictions of year, status, and language of publications. The inclusion criteria consisted of selecting only experimental studies comparing the influence of teriparatide in tooth movement of male Wistar rats. The exclusion criteria consisted of experiments with female rats or other experimental animals, and animals with pathologic conditions. The eligible studies were evaluated based on methodological quality. Two trained examiners performed all the research steps.ResultsThe initial sample comprised 700 studies, which was reduced to 664 after the exclusion of duplicates (n=36). Three articles were selected for the final qualitative analysis. The local administration of parathyroid hormone (PTH) 1-34 or PTH 1-84 revealed major effectiveness when compared with control groups and systematic administration. Additionally, the dilution of PTH 1-34 within methyl cellulose (MC) gel increased the time range for drug release, enabling to reduce the drug concentration without decreasing the effectiveness of tooth movement.ConclusionsTeriparatide demonstrated potential acceleration of tooth movement in Wistar rats depending on the drug concentration; drug administration; and time for drug release. Key words:Teriparatide, tooth movement, parathyroid hormone, orthodontics.
This study evaluated the influence of different levels of power density on resin polymerization in the staining of composite resins. Thirty-six specimens were made with composite resin (Z350 3M ESPE) with cylindrical Teflon matrix (8 mm X 1 mm). The light curing was performed with different degrees of power density for each group (n=12): 300mW/cm², 700mW/cm² e 1000mW/cm². Afterwards, the specimens had their color checked, with the help of a spectrophotometer and immersed in coffee solution during 7 days. After, a new measuring was done (CIEL*a*b* color system). Results showed, for Δa, only G1000 group obtained a significantly lower value, and the same result was found in the evaluation of Δb. For ∆E and ∆L, no significant differences were found between groups. It is concluded that, low and medium power density entails more reddish and bluish composite resin, while the specimens submitted to high power density and then immersed in coffee did not present color change in a short term.
Direitos para esta edição cedidos à Atena Editora pelos autores. Todo o conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons. Atribuição-Não-Comercial-NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0). O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores, inclusive não representam necessariamente a posição oficial da Atena Editora. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. Todos os manuscritos foram previamente submetidos à avaliação cega pelos pares, membros do Conselho Editorial desta Editora, tendo sido aprovados para a publicação com base em critérios de neutralidade e imparcialidade acadêmica. A Atena Editora é comprometida em garantir a integridade editorial em todas as etapas do processo de publicação, evitando plágio, dados ou resultados fraudulentos e impedindo que interesses financeiros comprometam os padrões éticos da publicação. Situações suspeitas de má conduta científica serão investigadas sob o mais alto padrão de rigor acadêmico e ético.
This research aimed to assess the effect of aluminum oxide sandblasting and discs on the bond strength of metal brackets rebonded on artificially eroded enamel. Fifty-four bovine incisors were divided into groups: Control (Artificial Saliva), AlOx (Aluminum oxide sandblasting), and SL (Aluminum oxide discs). They had their enamel surface flattened with Al2O3 discs and a metallographic polisher, then Knoop microhardness was assessed. AlOx and SL specimens were eroded with Coca-Cola™ for 1 minute, 3 times a day for 7 days. Metal brackets were bonded to the tooth. Shear strength was measured by an EMIC universal testing machine (0.5 mm/min). The Adhesive Remnant Index (ARI) was performed after shearing through magnifying glass (10X). Kolmogorov-Smirnov, Levene, homoscedasticity and ANOVA tests were applied to assess microhardness and shear strength (p=0.163). All groups presented shear bond strength with no significant differences. The ARI showed statistically significant difference between the groups. The prevalence for the control group was ARI 3. However for AlOx and SL, ARI 1 and 2 prevailed. The aluminum oxide sandblasting and aluminum oxide discs did not positively increase the bond strength of brackets when bonded to artificially eroded enamel. The ARI indicated that eroded teeth present higher resin adhesion to enamel.
O medo e a ansiedade podem interferir negativamente no procedimento odontológico, sendo importante o estudo de meios farmacológicos e/ou não farmacológicos de amenizá-los. Dessa forma, objetivou-se conhecer a percepção dos usuários de Unidades Básicas de Saúde (UBS) do município de Ribeirópolis - SE sobre a ambiência da sala de espera odontológica e aspectos psicossociais envolvidos neste âmbito. Coletaram-se dados por meio de entrevista utilizando-se a Dental Anxiety Scale (DAS) e o Perceived Hospital Environment Quality Indicator (PHEQI), além de questões socioeconômicas e educacionais. Foram entrevistados 308 pacientes, em 4 UBSs. Relacionando a DAS com as variáveis socioeconômicas, verifica-se diferença estatisticamente significativa para os itens gênero e idade, sendo que 72.7% dos avaliados apresentam ansiedade dental. Aplicando o PHEQI, 60% consideram o ambiente clínico em boa qualidade ou condições. Conclui-se que os usuários consideram a ambiência conveniente às suas condições socioeconômicas, mas vislumbram a necessidade de melhorias. Por fim, reafirma-se que o ambiente da sala de espera é capaz de interferir positiva ou negativamente na ansiedade relativamente à harmonia de sua ambiência.
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