RESUMO
Amelogenesis imperfecta is a genetic disorder that causes defective enamel development in both the primary and permanent dentitions. Significant tooth structure damage often results in various pulpal symptoms, occlusal disharmony, impaired function, and esthetic disfigurement. These problems pose great challenges to the clinician when rehabilitating patients with amelogenesis imperfecta. This case report describes an uncomplicated and logical way to reorganize, temporize, and completely restore an extensively damaged dentition caused by amelogenesis imperfecta.
Assuntos
Amelogênese Imperfeita/reabilitação , Planejamento de Assistência ao Paciente , Resinas Acrílicas/química , Adulto , Resinas Compostas/química , Coroas , Esmalte Dentário/anormalidades , Materiais Dentários/química , Porcelana Dentária/química , Doenças da Polpa Dentária/terapia , Restauração Dentária Permanente/métodos , Facetas Dentárias , Estética Dentária , Feminino , Seguimentos , Ligas de Ouro/química , Humanos , Registro da Relação Maxilomandibular , Má Oclusão/terapia , Cimentos de Resina/química , Tratamento do Canal Radicular , Dimensão VerticalRESUMO
STATEMENT OF PROBLEM: Early loss of magnetic keepers in cast gold posts is seen in clinical practice. PURPOSE: The purpose of this vitro study was to investigate the effect of burn-out temperature on the retention of magnetic keepers in cast gold alloy and on the thickness of the oxide layer at the keeper-alloy interface. MATERIAL AND METHODS: One hundred and five keepers (Magfit EX) were cast with gold alloy (Protor 3) at 3 different burn-out temperatures: 500 degrees C, 600 degrees C, or 700 degrees C (n=35). To test for retention of keepers, 60 specimens (n=20) were tested to failure in tension mode in a universal testing machine (UTM); 45 specimens (n=15) were sectioned, and the interface was evaluated under a scanning electron microscope (SEM). Tensile force data were analyzed with 1-way ANOVA, and SEM data were analyzed with 1-way repeated measures ANOVA. Bonferroni multiple comparisons were performed for post hoc analysis (alpha=.05). RESULTS: Retention of the keepers was significantly higher at lower burn-out temperatures (P<.001). The retention of the keepers became unpredictable and immediate failures were observed at a burn-out temperature of 700 degrees C. Oxide formation at the keeper-alloy interface was significantly less at lower burn-out temperatures (P<.001). CONCLUSIONS: A burn-out temperature of 500 degrees C for casting the Magfit EX keeper with type IV high-strength gold alloy is recommended.
