This study evaluated the influence of the surface treatment and aging on the biaxial flexural strength of ceramic materials cemented to a dentin analogue. One hundred twenty disc-shaped specimens were allocated into 12 groups considering three study factors: ceramic material (lithium disilicate, leucitebased ceramic and hybrid ceramic), surface treatment (10% hydrofluoric acid etching + silane or selfetching glass-ceramic primer) and Aging (with 10,000 thermocycles of 5-37-55°C or without). A tri-layer assembly was designed to mimic a cemented restoration (Variolink N) into a dentin analogue. All samples were submitted to the biaxial flexural strength assay. The flexural strength in MPa was calculated using the finite element method for each sample considering thickness, material properties, and the load to fracture during the in vitro test. Fractographic analysis was also performed. The data was evaluated using three-way ANOVA and Tukey test ( = 5%). ANOVA showed influence for the Material*Treatment*Aging interaction on the flexural strength (p = 0.011). The highest strength was calculated for lithium disilicate ceramic + self-etching ceramic primer without aging (499 ± 17 MPa)A and the lowest value for hybrid ceramic material + acid etching with aging (424 ± 48 MPa)E. According to the Weibull modulus, the most predictable strength was calculated for lithium disilicate + acid etching after aging. Acid etching or self-etching ceramic primer promotes similar immediate biaxial flexural strength for each evaluated ceramic. In the long-term, superior strength was observed using acid etching for lithium disilicate and the self-etching ceramic primer for the hybrid ceramic while no difference was observed for leucite-based ceramic.

No abstract

Several methodologies and techniques are currently available so as to dissipate energy in engineering systems; most of them are either not re-usable, or complex in mechanism. This paper introduces an innovative re-usable energy absorption device, based upon the working principles of Equal Channel Angular Extrusion, and known as UREAD (Universal Re-usable Energy Absorption Device). This study compares the behaviour of different "low-density" deformable materials (a range of silicon rubber grades) inserted in a UREAD unit and loaded under impact condition. The energy absorbed was experimentally measured and compared against the impact energy. It was possible to dissipate levels as high as 74.91% of the impact energy when using a simple set-up, and the device re-usability was demonstrated.

A análise facial consiste em uma etapa importante do diagnóstico e avaliação dos resultados obtidos na harmonização orofacial. Para avaliação dos resultados de procedimentos estéticos, fotografias são muito utilizadas, porém novas ferramentas são necessárias para facilitar a visualização dos pacientes quanto aos ganhos estéticos. Os scanners faciais 3D surgem como alternativa para tal finalidade. O objetivo deste estudo foi analisar, através de fotografias e escaneamento 3D da face, o ganho de volume labial após intervenção de preenchimento. A paciente apresentava insatisfação com relação aos seus lábios. Durante a avaliação, constatou-se ausência de volume e contorno labial. Antes de iniciar o procedimento, realizou-se protocolo fotográfico e escaneamento facial (E1). Para o procedimento, foi utilizada uma seringa de 1 mL de ácido hialurônico. O escaneamento foi feito no pós-imediato (E2), após 10 dias (E3) e após 40 dias da intervenção (E4). Nesta mesma consulta após 40 dias, foi realizado injeção da segunda seringa de ácido hialurônico escaneamento do pós-imediato (E5). Após 40 dias, a paciente voltou (E6). Após análise comparativa das malhas, foi possível verificar ganho de 3 mm entre E1 e E2. Na comparação do pré (E1) e após 10 dias (E3), verificou-se volumização total de 1,85 mm, demonstrando que quase 40% do volume no pós-imediato é edema. Em E6, após 40 dias da aplicação da segunda seringa, foi possível quantificar ganho de 2,12 mm no lábio superior quando comparado a E1. Pode-se concluir que o escaneamento 3D contribui expressivamente para avaliação dos resultados alcançados em procedimentos estéticos.