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)

Management of permanent teeth with necrotic pulps and open apices according to the stage of root development.

BACKGROUND: This paper analyzed the distribution of treatments for permanent teeth with necrotic pulps and open apices according to the stage of root development. MATERIAL AND METHODS: Dental records from all root canal procedures performed in permanent teeth with necrotic pulps and open apices over a period of 14 years by residents of the Speciality of Endodontics, University of Guadalajara, Mexico, were analized. RESULTS: Records from 206 treatments were mainly divided into the following 3 different stages according to criteria described by Cvek: stage IV (n = 79, 38.3%), stage V (n = 66, 32%) and stage III (n = 53, 25.7%). Few cases involved the initial stages of root development (stages I and II) (n = 8, 3.8%). Such teeth were submitted to four different treatments: MTA apical barrier (n = 69), Ca(OH)2 replacements (n = 34), gutta-percha (n = 67) and a plug of Ca(OH)2/gutta-percha (n = 36). The teeth with intermediate root development (Cvek stage III) showed a predilection for the MTA apical barrier and Ca(OH)2 replacement techniques (P ≤ 0.001). Furthermore, the stage of root development did not influence the apical extent of the root filling. CONCLUSIONS: The finding of permanent teeth with necrotic pulp and open apices is not exclusive to young patients with an open apex. Moreover, teeth with fragile, irregular and divergent apical morphologies, such as Cvek's stages´ I and II, were not common and may be considered to be unusual findings. The diverse endodontic procedures were reliable regardless of the stage of root development. Key words:Incomplete root formation, Open apex, Epidemiological studies, Root development.

Segundo molar maxilar con cuatro raíces y cinco conductos radiculares / Maxillary second molar with four roots and five root canals

El segundo molar maxilar comúnmente presenta tres raíces (dos raíces bucales y una raíz palatina) y tres conductos radiculares (un conducto radicular por cada raíz). No obstante, a pesar de que es muy inusual encontrar variaciones en su morfología, es importante conocer las posibles alteraciones que pueden presentarse con el objetivo de evitar accidentes operatorios. En este caso se reporta el tratamiento endodóntico de un segundo molar maxilar con cuatro raíces y cinco conductos radiculares (AU)

The maxillary second molar usually exhibits 3 roots (2 buccal roots and 1 palatal root), as well as 3 root canals (1 root canal corresponding to each root). Even though it is unusual to find variations in its morphology, it is important to know the possible alterations that could occur if such variations are found, in order to prevent operative accidents. This paper reports a case of endodontic treatment applied to a maxillary second molar with 4 root and 5 root canals (AU)

Evaluación del sellado apical de sistemas resinosos en la obturación de conductos radiculares: “Estudio in Vitro”

El propósito de este estudio fue evaluar el sellado apical entre los cementos AH plus y los sistemas resinosos de obturación Endo-Rez y Epiphany. Se incluyeron 68 premolares humanos monorradiculares de reciente extracción, los cuales fueron decoronados e instrumentados con la técnica corono-apical hasta la lima # 50. Posteriormente, se dividieron en tres grupos de 20 raíces cada uno para ser obturados por condensación lateral: Grupo 1.- AH Plus, Grupo 2.- Endo-Rez, Grupo 3.- Epiphany y dos grupos de cuatro especímenes como controles (positivo y negativo). Los especímenes fueron teñidos con azul de metileno al 2% durante 48 hs en un ambiente de vacío. Los resultados revelaron una filtración promedio de 0.27 mm con AH Plus, de 0.40 mm para el Endo-Rez y de 0.41 mm para el Epiphany. La prueba de ANOVA complementada con la prueba DSH Post-Hoc de Tukey’s Test reveló los mejores resultados con AH plus (p<0.05), y entre los otros grupos no hubo diferencias estadísticas significativas. Bajo las condiciones de éste estudio concluimos, que el cemento AH Plus mostró las mejores condiciones de sellado apical.

The purpose of this study is to compare the capacity of apical sealed between the cements AH Plus, Endo-Rez and Epiphany. Sixty eight human single-rooted inferior premolars of recent extraction were included. The specimens were decrowned and instrumented with the crown-down technique until the #50 file. The teeth were randomly divided into three groups of 20 each one and obturated with the technique of lateral condensation. Group 1: AH Plus, Group 2: Endo-Rez, Group 3: Epiphany and two groups of fourth specimens for control (positive and negative). The specimens were prepared to be submerged in 2% blue of methylene solution by 48 hours in to vacuum atmosphere. The results showed an apical sealed average of 0.27 mm for AH Plus, 0.40 mm for the Endo-Rez and 0.41 mm for the Epiphany. The ANOVA test supplemented with the Post-Hoc Tukey’s HSD Test revealed best apical sealed for the group with AH plus (p <0.05) and no statically significant differences were found between other groups. Under the conditions of this study, the AH Plus cement showed the best conditions of apical sealed.

Evaluación de la resistencia a la tensión entre diferentes sistemas de pernos intrarradiculares: estudio in vitro / Evaluation of tensile strength between different intraradicular bolt systems: in vitro study

La reconstrucción de los dientes tratados endodónticamente juega un papel importante en el pronóstico, ya que el 60% de los fracasos endodónticos se relacionan con la rehabilitación. Diversos sistemas y materiales se han utilizado en la reconstrucción de los dientes, alternando el diseño, material del perno, agente cementante y el tipo de muñón utilizado, evidenciando resultados contradictorios. Evaluar la resistencia a la tensión (RT) entre tres diferentes sistemas de pernos intrarradiculares. Se incluyeron 45 premolares monorradiculares, los cuales fueron instrumentados y preparados para ser reconstruidos con diversos sistemas de pernos. Estos fueron divididos en tres grupos: 1.-Sistema Perno-Muñón Colado (PMC), 2.-Sistema Para-Post Acero (PPA) y 3.-Sistema Para-Post Fiber-Lux (PPFL), cementados uniformemente con un cemento resinoso y sometido a RT en una máquina Instrom. La máxima RT fue para el sistema PMC (11.11 Mp), seguido por PPFL (3.42 Mp) y PPA con (3.14 Mp). La prueba de ANOVA complementada con el Post-Hoc DSH de Tukey reveló diferencias significativas entre PMC vs PPA y PPFL (p<0.05), entre PPA vs PPFL no hubo diferencias significativas. Ningún sistema prefabricado se desalojó a la prueba de tensión y los muñones se fracturaron. El sistema de PMC registró mayor RT que los sistemas PPA y PPFL (p<0.05) entre los prefabricados no existieron diferencias significativas

The reconstruction of teeth endodontically treated represents an important role, since the 60% of the endodontic failures relate to the rehabilitation. Diverse technical and material they have been utilized in the reconstruction of the posts, alternating the design, material, luting agent and the type of core utilized, showing contradictory results. Evaluating the tensional resistance (TR) of three post-endodontical reconstruction systems.Forty-five human premolars were used for this study, which were instrumented and prepared for receiving a post. They were divided into three groups: l. - casted post and core system (CPC), 2. - Steel Para-Post system (SPP) and 3. - Para-Post Fiber-Lux system (PPFL), which they were cemented with resinous cement and submitted to TR in Instrom machine. The maximum TR was for CPC (11.11 Mp), followed by PPFL (3.42 Mp) and SPP with (3.14 Mp). The ANOVA test supplemented with Post-Hoc HSD de Tukey´s revealed statistically differences significantly between CPC vs SPP and PPFL (p<0.05), among SPP vs PPFL do not there was statistically differences significantly. The prefabricated post, not there was dislocated and the cores were fractured. The CPC registered the higher TR that the prefabricated post (p<0.05) and among the prefabricated post did not exist differences significantly

Estudio descriptivo de la gutapercha PRODENT por medio de MEB y EDX in vitro / A descriptive study of the PRODENT gutta-percha by means of SEM and EDX: an in vitro study

El propósito de este estudio fue analizar la morfología y composición química de conos de gutapercha PRODENT por medio de MEB y EDX. Se incluyeron al azar 12 conos de gutapercha de calibres y lotes diferentes, los cuales se estudiaron del D1 al D16, seis conos de utilizaron para el estudio morfológico y el resto para microanálisis, el cual se realizó en la estructura interna y externa. La evaluación de la morfología reveló un alto grado de regularidad en las zonas estudiadas. El microanálisis evidenció que la capa externa está constituida por nueve elementos y la estructura interna por 11. Se encontró que dependiendo del calibre del cono, existe variabilidad en los elementos constitutivos, entre los cuales resaltan el zinc, oxígeno, bario y sodio. Bajo las condiciones de este estudio, concluimos que la gutapercha PRODENT ofrece características morfológicas y de composición química satisfactorias para su uso clínico