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. (AU)

Intra- and Interobserver Agreement during the Assessment of the Different Stages of Root Development Using 4 Radiographic Classifications.

INTRODUCTION: This study analyzed intra- and interobserver agreements during radiographic assessment of the different stages of root development using the dichotomous, Moorrees, Demirjian, and Cvek classifications, as well as the effect of the observer's level of experience on the result. METHODS: Two hundred eighty-five digital periapical radiographs were examined via visual inspection by 3 experienced and 3 nonexperienced observers (n = 6) under strict technological and viewing conditions. After observer calibration, determination of the presence or absence of an open apex and the assignment of a root development stage according to the different subdivisions of the 4 indexes were performed. This evaluation was carried out by each observer in duplicate in the first round (n = 8) and repeated in the second round (n = 8). The 16 examinations performed by each observer (N = 96) were analyzed to determine the percentage of concordance followed by intraobserver, interobserver, and global observer agreement using the kappa coefficient and a weighted kappa. Additionally, to determine the level of concordance between the visual determination of an open or closed apex and the apical foramen width measured in millimeters, a dichotomized kappa coefficient was applied. RESULTS: A good level of global observer agreement was found for the dichotomous, Demirjian, and Cvek classifications. However, a significantly low percentage of total concordance and global observer agreement (6.66% and 0.498, respectively) was obtained using the Moorrees classification, which was more pronounced among nonexperienced observers (0.247). Apical foramen width measurements indicated the presence of 143 roots with an open apex (50.2%) and 142 with a closed apex (49.8%), and the dichotomized kappa coefficient test revealed a good level of agreement during the visual determination of an open or closed apex (range, 0.611-0.636). CONCLUSIONS: The classifications of Cvek and Demirjian provided reliable results when determining the different stages of root development. In contrast, the Moorrees classification provided the lowest agreement values, with a significant negative effect among nonexperienced observers. Finally, the visual estimation of the presence (or absence) of an open apex provided a good level of concordance with the radiographic apical foramen width.

Morfología de la punta del bisel de agujas dentales post-utilización en la técnica de bloqueo del nervio alveolar inferior / Morphology of bevel's tip of dental needle post-utilization in inferior alveolar nerve block technique

Objetivo: El propósito del estudio fue evaluar la punta del bisel de 100 agujas dentales, calibre 30 corta, utilizadas en la técnica de anestesia mandibular después de 1, 2 y 3 inserciones, y de una inserción única en la que hubo contacto con hueso. Material y métodos: Se emplearon 25 agujas de cada una de las marcas: Septodont, Monoject, Hypo y Terumo, que fueron observadas al MEB, en vista de frente al bisel y de perfil, y analizadas las características de la punta. Los rasgos morfológicos registrados incluyeron punta intacta, despuntada, punta con doblez hacia el bisel y doblez hacia fuera del bisel. Los resultados se sometieron a la prueba de chi cuadrado. Resultados: Se realizaron comparaciones intra e inter-grupos, no encontrándose diferencias estadísticas significativas de acuerdo al número de inserciones y a la marca. El 15% de las agujas que no fueron insertadas presentaron alteraciones de fábrica como: porosidades del bisel, bordes aserrados y rebordes. Todas las puntas que contactaron con hueso sufrieron modificaciones. Conclusiones: Se sugiere la preferencia por las técnicas anestésicas sin contacto óseo y la consideración de que las agujas nuevas pueden presentar alteraciones

Objective: The aim of this study was to evaluate the tip of the bevel of 100 dental needles 30G short, unused, used in inferior alveolar nerve block, after 1, 2 and 3 insertions, and after a single injection with bone contact. Material and methods: Four different trademarks were evaluated (25 Septodont, 25 Monoject, 25 Hypo and 25 Terumo dental needles) and was observed in SEM, in lateral and frontal views, in order to evaluate the changes of the bevel’s tip. The morphological changes register were: intact, blunt, hooked towards bevel and hooked away bevel. Chi square test was used to compare data. Results: The groups were compared, and there were not found statistical differences between number of insertions and needle tip nor damage related to trademark. All the needles with bone contact were deformed. Results showed 15% of the unused needles had alterations. There were found manufacturing fault, in dental needles of the same lot, such as: porous bevel, blanges and serrated edges. Conclusions: Preference for non-bone contact anesthesia techniques is suggested, and consider that brand new needles may be altered