RESUMEN
Background: Dentinogenesis imperfecta type I (DGI-I) is a hereditary alteration of dentin associated with osteogenesis imperfecta (OI). Aim: To describe and study the morphological characteristics of DGI-I with scanning electron microscopy (SEM). Material and methods: Twenty-five teeth from 17 individuals diagnosed with OI and 30 control samples were studied with SEM at the level of the enamel, dentin-enamel junction (DEJ) and four levels of the dentin, studying its relationship with clinical-radiographic alterations. The variables were analysed using Fisher's exact test, with a confidence level of 95% and asymptotic significance. Results: OI teeth showed alterations in the prismatic structure in 56%, interruption of the union in the enamel and dentin in 64% and alterations in the tubular structure in all of the cases. There is a relationship between the severity of OI and the morphological alteration of the dentin in the superficial (p = 0.019) and pulpar dentin (p 0.004) regions. Conclusions: Morphological alterations of the tooth structure are found in OI samples in the enamel, DEJ and dentin in all teeth regardless of the presence of clinical-radiographic alterations. Dentin structural anomalies and clinical dental alterations were observed more frequently in samples from subjects with a more severe phenotype of OI.
RESUMEN
PURPOSE: To examine the ultrastructural characteristics of a fiber-reinforced composite (FRC) and its behavior in vitro as a framework for fixed partial dentures (FPDs). METHODS: A total of 40 specimens were prepared using extracted teeth fixed in methacrylate blocks as supports for the FPD, then the specimens were divided into four groups depending on whether a retaining box was used to fix the FPD to the support teeth, and on whether a composite pontic was assembled on top of the fibers. Fracture testing was performed in a universal testing machine (1 mm/minute). Fracture strength values and failure types were statistically compared for each group. RESULTS: Using retaining boxes did not improve the mechanical behavior of the restorative system. The weakest element of the system was the composite tooth constructed on top of the FRC.
Asunto(s)
Resinas Compuestas/química , Materiales Dentales/química , Vidrio/química , Grabado Ácido Dental/métodos , Recubrimiento Dental Adhesivo , Análisis del Estrés Dental/instrumentación , Diseño de Dentadura , Retención de Dentadura , Dentadura Parcial Fija con Resina Consolidada , Humanos , Curación por Luz de Adhesivos Dentales/métodos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Nanocompuestos/química , Estrés Mecánico , Propiedades de SuperficieRESUMEN
Fundamento: al combinar un sistema adhesivo con la amalgama de plata se pretende mejorar el sellado de la Interfase. En este trabajo se valora la capacidad de sellado de los adhesivos fotopolimerizables en este tipo de restauraciones. Material y método: mediante un estudio de penetración de colorante y un sistema informático digital, se determinó cuantitativamente la microfiltración de restauraciones de amalgama realizadas con adhesivos fotopolimerizables, barniz de copal y un sistema autopolimerizable. Resultados: el empleo de sistemas adhesivos en restauraciones de amalgama genera una interfase entre la amalgama y el adhesivo y otra entre el adhesivo y la dentina. La microfiltración en la primera interfase es mayor en los adhesivos fotopolimerizables respecto al autopolimerizab e y el barniz de copal. Sin embargo, la microfiltración en la segunda interfase es menor en los dos sistemas adhesivos respecto al barniz de copal (p<0.05) Conclusión: los adhesivos fotopolimerizables producen un sellado insuficiente en restauraciones de amalgama (AU)
