RESUMO
This study investigated the impact of 'storage condition' and 'period of storage' on selected physico-mechanical properties and fracture reliability of a resin-based composite (RBC). Specimens, prepared from a nanofilled RBC (Filtek Z350 XT; 3M ESPE), underwent tests for degree of conversion (DC), flexural strength (σ), flexural modulus (E), and hardness. The specimens were initially grouped into dry storage at 37°C or wet storage in distilled water at 37°C. Subsequently, they were further divided into four subgroups based on the period of storage: 6, 24, 72, or 168 hours. Specimens tested immediately after preparation served as control. Data analysis employed two-way ANOVA and Weibull analysis (α = 5%). Compared to the control, an increase in DC was observed only after 72 hours of dry storage; σ showed higher values after both dry and wet storage, regardless of the storage period (except for the group wet-stored for 168 hours); E increased with dry storage for at least 24 hours or wet storage for 72 hours; and hardness increased after dry storage for at least 24 hours or wet storage for up to 72 hours. The Weibull modulus remained unchanged under any of the distinct storage conditions. Dry storage resulted in greater characteristic strength than the control, whereas wet storage contributed to higher strength values only at shorter periods (up to 24 hours). Overall, the inherent properties of RBCs with a similar composition to that tested in this study may change with varying storage conditions and periods.
Assuntos
Resinas Compostas , Resistência à Flexão , Testes de Dureza , Dureza , Teste de Materiais , Resinas Compostas/química , Fatores de Tempo , Análise de Variância , Reprodutibilidade dos Testes , Valores de Referência , Propriedades de Superfície , TemperaturaRESUMO
Objetivo: Examinar estruturas curriculares de cursos de Odontologia em Instituições de Ensino Superior (IES) no Brasil, focando na integração e oferta da disciplina de harmonização orofacial (HOF). Métodos: Analisamos matrizes curriculares disponíveis de todas as IES no Cadastro Nacional de Cursos e Instituições de Educação Superior do Ministério da Educação (MEC) em todas as regiões brasileiras. Foram avaliados a categoria administrativa das IES (pública ou privada), oferta de HOF, localização, perfil do componente curricular, formato de ensino, período de oferta e carga horária. Resultado: Desconsiderando instituições com múltiplas localidades no mesmo Estado, identificamos 455 cursos de graduação em Odontologia em todo o país. Quanto à inserção de HOF, 84 IES a têm como componente curricular, sendo 58,3% obrigatórias. A carga horária varia de 20 a 120 horas nas matrizes analisadas. Referente ao período ofertado, há variação do 1° ao 5° ano, sendo mais comumente ofertado a partir do 4° ano. Conclusão: Conclui-se que a oferta de HOF como componente curricular é presente em 18,46% das IES.
RESUMO
Abstract This study investigated the impact of 'storage condition' and 'period of storage' on selected physico-mechanical properties and fracture reliability of a resin-based composite (RBC). Specimens, prepared from a nanofilled RBC (Filtek Z350 XT; 3M ESPE), underwent tests for degree of conversion (DC), flexural strength (σ), flexural modulus (E), and hardness. The specimens were initially grouped into dry storage at 37°C or wet storage in distilled water at 37°C. Subsequently, they were further divided into four subgroups based on the period of storage: 6, 24, 72, or 168 hours. Specimens tested immediately after preparation served as control. Data analysis employed two-way ANOVA and Weibull analysis (α = 5%). Compared to the control, an increase in DC was observed only after 72 hours of dry storage; σ showed higher values after both dry and wet storage, regardless of the storage period (except for the group wet-stored for 168 hours); E increased with dry storage for at least 24 hours or wet storage for 72 hours; and hardness increased after dry storage for at least 24 hours or wet storage for up to 72 hours. The Weibull modulus remained unchanged under any of the distinct storage conditions. Dry storage resulted in greater characteristic strength than the control, whereas wet storage contributed to higher strength values only at shorter periods (up to 24 hours). Overall, the inherent properties of RBCs with a similar composition to that tested in this study may change with varying storage conditions and periods.