Reduction of NrF2 as coadjuvant during the development of persistent periapical lesions.

BACKGROUND: Persistent periapical lesions (PPL) are the result of pulpar necrosis induced by bacterial infection resulting in bone degradation and culminating with the loss of dental piece. Pathological changes in the peripapice are associated with the presence of free radicals. The transcription factor Nrf2 is the main regulator of the endogenous antioxidant response against oxidative stress and has been implicated in the regulation of osteoclastogenesis.The aim is to determine the oxidative condition in samples from patients with Persistent Periapical Injuries as a detonating factor of tissue damage. MATERIAL AND METHODS: An observational, descriptive, cross-sectional study was carried out in samples with PPL (cases) and samples by removal of third molars (controls) obtained in the clinic of the specialty in endodontics, University of Guadalajara. Samples were submitted to histological staining with Hematoxylin-Eosin, lipoperoxide analysis, Superoxide Dismutase (SOD), Glutathione-Peroxidase (GPx) and Catalase (CAT) activities were determined by immunoenzymatic assays and NrF2 by Western Blot analysis. RESULTS: Samples from PPL patients histologically showed an increased presence of lymphocytes, plasma cells, and eosinophils, as well as a decrease in extracellular matrix proteins and fibroblast cells. There was a rise in lipid peroxidation, GPx and SOD activities, but an important decline (36%) in Catalase activity was observed (p<0.005); finally, NrF2-protein was diminished at 10.41%. All comparisons were between cases vs controls. CONCLUSIONS: The alterations in antioxidants endogenous NrF2-controlled are related to osseous destruction in patients with PPL.

Evaluación del sellado marginal de diferentes materiales utilizados durante el blanqueamiento ambulatorio, estudio in vitro / Evaluation of the marginal sealed of differnet materials used during the ambulatory blanqueamiento, in vitro study

Objetivo: el propósito de este estudio fue evaluar el sellado marginal de diferentes materiales intracoronalmente después de la amputación parcial de la raíz hasta una profundidad de 5mm. Los especímenes se dividieron en siete grupos de 30 premolares cada uno. Una pasta blanqueadora acondicionada con azul de metileno se colocó con un espesor de 2mm y el resto de la cavidad fue obturada con diferentes materiales: Resina compuesta, lonómero de Vidrio, IRM, Fosfato de Zinc, Cavit R, Provisit y Carboxilato. Fueron almacenadas en solución salina durante ocho días. El sellado marginal se evaluó mediante una tabla de valores y fueron analizados con la prueba X2. Resultados: Los resultados revelaron el mejor sellado marginal para el CAvit R (p.001) y resina compuesta (p.0,05), y el sellado más pobre para IRM y fosfato de zinc. Conclusiones: Bajo las condiciones de este estudio concluimos que el Cavit R y la resina comuesta ofrecieron un mejor sellado marginal durante el blanqueamiento ambulatorio (AU)

Objective: The purpose of this study was to evaluate the marginal seal of various materials used in the cavity during the bleaching. Material and Methods: We included 210 human premolars of arches which were prepared intracrowne after partial amputation of the root to a depth of 5mm. The specimens were divided into seven groups of 30 premolars each. Subsequently, the pulp bleaching fitted with methylene blue was placed with a thickness of 2 mm and the rest of the cavity was sealed with different materials: composite resin, glass ionomer, IRM, zinc phosphate, Cavit R, Provisit and carboxylate. Were stored in saline solution for eight days. The marginal seal was evaluated through a table of values, data were analyzed with the X2 test. Results: The results showed the best marginal seal for Cavit R (p<0,01) and resin composite (p<0,05) groups and poorer sealing for IRM and Zinc Phosphate. Conclusion: Under the conditions of this study concluded that R Cavit and resin composite provided a better marginal seal during the bleaching (AU)