¿Afecta el tratamiento con corticoides en los periodos prenatal y posnatal el neurodesarrollo del recién nacido prematuro? / Does corticosteroid treatment during the pre and postnatal periods affect the neurodevelopmental outcome of premature newborns?

Resumen Introducción. Los glucocorticoides, ampliamente utilizados en el periodo perinatal, pueden asociarse con efectos adversos en el neurodesarrollo. Objetivo. Analizar los resultados del tratamiento con corticoides en el periodo prenatal y en el posnatal en el neurodesarrollo de una cohorte de recién nacidos de muy bajo peso. Materiales y métodos. Se hizo un estudio prospectivo de cohortes en los recién nacidos de muy bajo peso hospitalizados en la unidad de cuidados intensivos neonatales de un hospital de tercer nivel entre el 2008 y el 2013. Se comparó el neurodesarrollo entre aquellos que no recibieron tratamiento prenatal con corticoides y quienes recibieron el esquema completo (dos dosis de 12 mg de betametasona) o el incompleto (una dosis). También, se compararon los resultados en el neurodesarrollo de los recién nacidos que no recibieron tratamiento posnatal y aquellos que sí (dexametasona sistémica a partir de la primera semana de vida). Se evaluó la función motora, la neurosensorial y la cognitiva, así como los trastornos de conducta durante los dos primeros años de vida. Resultados. Se analizaron 225 recién nacidos de muy bajo peso; 83,6 % de las madres había recibido tratamiento prenatal con corticoides (esquema incompleto: 24 %; esquema completo: 59,6 %). Durante el periodo posnatal solamente el 13,3 % había recibido dexametasona sistémica. El seguimiento neurológico se llevó a cabo en 194 neonatos. En el análisis de regresión logística no se detectó que el tratamiento prenatal no el posnatal se asociara con más trastornos neurológicos, ni hubo diferencias significativas entre quienes recibieron el esquema completo y los que recibieron el incompleto durante el periodo prenatal. Conclusión. Los resultados de este estudio no pudieron demostrar que el tratamiento perinatal con corticoides se asociara con peores resultados en el neurodesarrollo en recién nacidos de muy bajo peso.

Abstract Introduction: Glucocorticoids, widely used in the perinatal period, may be associated with adverse neurodevelopmental effects. Objectives: To analyze neurodevelopmental outcomes in a cohort of very low birth weight newborns treated with antenatal and/or postnatal corticosteroids. Materials and methods: This was a prospective cohort study in which we included all very low birth weight babies admitted to the neonatal intensive care unit of a tertiary hospital between 2008 and 2013. We compared the neurodevelopment among very low birth-weight newborns who did not receive prenatal corticosteroid therapy and those who received a complete course (two doses of 12 mg betamethasone) and an incomplete course (one dose), and between those who did not receive postnatal corticosteroid therapy and those who received it (systemic dexamethasone after the first week of life). Motor, neurosensory and cognitive functions, as well as behavior disorders during the first two years of age were evaluated. Results: A total of 225 very low birth weight newborns were analyzed; 83.6% received prenatal corticosteroid therapy (24% incomplete treatment schedule and 59.6% complete schedule). Only 13.3% received systemic dexamethasone during the postnatal period. Neurological monitoring was performed in 194 infants. Logistic regression analysis did not detect an association between prenatal and postnatal corticosteroid therapy and more neurological disorders, and no significant differences were found among those who received complete and incomplete courses of prenatal corticosteroid therapy. Conclusion: These results did not demonstrate an association between perinatal corticosteroid therapy and worse neurodevelopmental outcomes in very low birth weight newborns.

Physicochemical properties of endodontic sealers of different bases

OBJECTIVE: To assess the setting time (ST), flow (FL), radiopacity (RD), solubility (SB) and dimensional change following setting (DC) of different sealers (AH Plus®, Polifil, Apexit Plus®, Sealapex®, Endométhasone® and Endofill®) according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 57. MATERIAL AND METHODS: Five samples of each material were used for each test. For ST, cast rings were filled with sealers and tested with a Gilmore needle. For FL, the sealer was placed on a glass plate. After 180 s, another plate with 20 g and a load of 100 g were applied on the material, and the diameters of the discs formed were measured. In RD, circular molds were filled with the sealers, radiographed and analyzed using Digora software. For SB, circular molds were filled with the sealers, a nylon thread was placed inside the material and another glass plate was positioned on the set, pressed and stored at 37°C. Samples were weighed, placed in water, dried and reweighed. The water used for SB was analyzed by atomic absorption spectrometry. For DC, circular molds were filled with the sealers, covered by glass plates and stored at 37°C. Samples were measured and stored in water for 30 days. After this period, they were dryed and measured again. RESULTS: Regarding ST, AH Plus®, Apexit® and Endofil® sealers are in accordance with ANSI/ADA standards. Endométhasone's manufacturer did not mention the ST; Polifil is an experimental sealer and Sealapex® did not set. Considering RD, SB and DC, all sealers were in accordance with ANSI/ADA. The spectrometric analysis showed that a significant amount of K+ and Zn2+ ions was released from Apexit Plus® and Endofill®, respectively. CONCLUSION: Except for DC, all other physicochemical properties of the tested sealers conformed to ANSI/ADA requirements.

Radiographic analysis of root canal fillings: influence of two sealers on the perception of voids

The aim of this ex vivo was to investigate if two radiopaque root canal sealers with different formulations would influence the radiographic perception of root canal fillings. The root canals of 48 extracted maxillary canines were prepared and randomly assigned to 3 groups of 16 specimens each. In each group, the root canals were filled by lateral condensation of gutta-percha and one of the tested sealers: Endométhasone, Sealer 26, or a non-radiopaque sealer. A through-and-through void was simulated in half of the specimens from each group (n=8). The buccolingual radiographic images obtained were randomly interpreted for voids existence by a radiologist and an endodontist. The differences in sensitivity and specificity between groups and examiners were compared using, respectively, Fisher's Exact and McNemar tests at 5 percent significance level. Both radiopaque sealers caused a significant decrease in sensitivity at the coronal part of fillings. The use of Endométhasone increased specificity values for both coronal and apical portions of the root canal fillings. In conclusion, the tested sealers influenced the radiographic perceptions of laterally condensed root canal fillings in a different way.

O propósito deste estudo ex vivo foi investigar se dois cimentos obturadores de fórmulas diferentes influenciariam a percepção radiográfica de obturações de canais radiculares. Os canais radiculares de 48 caninos superiores extraídos foram preparados e divididos em 3 grupos. Em cada grupo os canais foram preenchidos através da condensação lateral da guta-percha e de um dos cimentos testados (Endométhasone, Sealer 26 e cimento não-radiopaco), e um defeito de ponta a ponta foi simulado em metade dos espécimes de cada grupo (n=8). As imagens radiográficas vestíbulo-linguais obtidas foram aleatoriamente interpretadas quanto à existência de defeitos por um radiologista e um endodontista. As diferenças em sensibilidade e especificidade entre os grupos e examinadores foram comparadas respectivamente usando-se os testes Exato de Fisher e McNemar ajustados ao nível de significância de 5 por cento. Ambos os cimentos radiopacos ocasionaram uma redução significativa da sensibilidade na parte cervical das obturações. O uso do Endométhasone aumentou os valores de especificidade para as porções cervical e apical das obturações dos canais radiculares. Concluiu-se que os cimentos testados influenciaram de maneira distinta a percepção radiográfica de obturações endodônticas executadas com condensação lateral.

Análise comparativa do potencial antimicrobiano de três medicações utilizadas no canal radicular / Comparative analysis of antimicrobial potential of three root canal dressing

O objetivo do presente estudo foi analisar o potencial antimicrobiano das medicações NDP, Pred-Fort associado a rifamicina e Otosporin quando em contato com bactéria comumente encontrada no interior do canal radicular,Staphylococcus aureus (ATCC 25923), em meio de cultura sólido Mueller Huinton. A infusão bacteriana foi preparada utilizando meio TSB, correspondente à escala 0,5 de McFarland. Foram utilizadas Placas de Petri, já esterilizadas, para acomodação de duas camadas de meio de cultura. Na base foram colocados 10 mL de Mueller Huinton e esperou-se solidificar. A segunda camada, também de 10 mL, foi preparada utilizando infusão bacteriana, diluída em 1 x 10 a 6ª em meio de cultura TSB e 5 mL de meio sólido, resultando na concentração de 15 X 10 a 5ª UFC/mL, que foi colocada sobre a base. Feito isto, foram acomodados discos de papel previamente embebidos nas modificações testadas nesta pesquisa sobre o meio. As placas foram acondicionadas em estufa durante 24h, a uma temperatura de 36°C, para análise dos resultados. Essa análise foi definida a partir da mensuração do halo de inibição, em milímitros, causados pela medicações, cujos valores foram submetidos à análise estatística. Segundo os resultados, houve formação de maiores halos de inibição quando da utilização, em ordem decrescente, do Pred-Fort + Rifamicina, do Otosporim e , finalmente, do NDP.

Comparative study of sealing capabilities and adhesiveness of injectable root canal sealers using pressure syringe technique.

The accuracy with which root canal space is sealed is a major determinant in the Endodontic success. Use of pressure-syringe to introduce root canal sealer in the root canal without gutta percha or silver cone represents a modification to current technique of obturation. This study investigates the sealing capabilities and adhesiveness of various root canal sealers with the use of pressure syringe technique. Apart from eliminating the use of solid core, pressure syringe technique can be used as a new obturation method since it showed better marginal sealability than the conventional technique.