Efecto del EDTAC y del ácido cítrico sobre la pared dentinaria. Variación del tiempo de exposición y la edad dentaria / Effect of EDTAC and citric acid on dentinal walls. Variation of exposure time and dental age

The aim of this study was to find a formula and application time for chelators effective in cleaning the root canal without causing erosion and considering dental age. The sample included 120 teeth: 60 taken from young patients and 60 from adult patients. They were instrumented and irrigated with 2.5% sodium hypochlorite (NaOCl). Each subgroup was divided randomly into six groups: 4 groups of 12 teeth and 2 control groups of 6 teeth. In the final irrigation, 17% ethylenediaminetetraacetic acid plus Cetavlón (EDTAC) or 10% citric acid was applied for 1 or 3 minutes according to each group. The results showed a high level of cleanliness, and a few showed erosion of the dentinal tubules. Satisfactory results were obtained in the removal of the smear layer when applying EDTAC or citric acid combined with NaOCl. Erosion was present in different degrees regardless of dental age, but it was indeed affected by the irrigant exposure time.

O objetivo deste estudo foi obter uma fórmula e um tempo de aplicação dos quelantes efetivos que permitam a limpeza das paredes do canal sem causar erosões, levando em consideração a idade dental. A amostra foi composta por 120 dentes, 60 de pacientes jovens e 60 de pacientes adultos, foram instrumentados e irrigados com hipoclorito de sódio (NaOCl) a 2,5%. Cada subgrupo foi dividido aleatoriamente em 6 grupos: 4 grupos de 12 dentes e 2 grupos de controle com 6 dentes cada um. Na irrigação final, ácido etilenodiaminotetracético com Cetavlón (EDTAC) 17% ou ácido cítrico 10% foi aplicado por 1 ou 3 minutos, dependendo do grupo. Os resultados mostraram um bom nível de limpeza com algumas amostras com erosão dos túbulos dentinários. Com EDTAC ou ácido cítrico combinado com NaOCl, resultados satisfatórios foram obtidos na remoção da camada de esfregaço . A erosão esteve presente em seus diferentes graus independentemente da idade dentária, mas não do tempo de exposição do irrigante.

Efecto de la aplicación activa con aplicadores mejorados de un adhesivo universal / Effect of the active application of a universal adhesive with improved applicators

RESUMEN Introducción: La permeabilidad dentinaria es conocida como el paso de fluidos, iones, partículas, moléculas y bacterias a través de la dentina bajo ciertas condiciones. Objetivo: Determinar la influencia de la aplicación activa con un aplicador mejorado de un adhesivo dentinario sobre la conductancia hidráulica dentinaria humana, in vitro. Métodos: Estudio experimental in vitro en 40 terceros molares libres de caries, con indicación de exodoncia, provenientes de pacientes sanos entre 15 y 30 años, previo consentimiento informado. Posteriormente se limpiaron, desinfectaron y conservaron para ser incluidos en bloques de resina epóxica. Luego se realizaron cortes transversales y se obtuvieron discos dentinarios de 1,5 mm de espesor y 25 mm de diámetro. Se dividieron en dos grupos de 20 unidades cada uno, se sometieron a grabado con ácido ortofosfórico al 37 por ciento, y se lavaron y secaron. Sobre una balanza de precisión se les aplicó adhesivo dentinario fotopolimerizable, registrando la fuerza ejercida. En el grupo 1 se usó un microbrush en la aplicación y en el grupo 2 un aplicador mejorado diseñado especialmente. Posteriormente cada muestra fue sometida a una cámara de difusión para obtener la tasa de flujo y luego calcular la conductancia hidráulica, la cual otorga información acerca de la permeabilidad de la dentina. Resultados: los resultados obtenidos fueron levemente menores en el grupo 2, sin embargo, experimentaron una distribución normal. Conclusiones: no existen diferencias significativas, al ser analizados estadísticamente bajo diversas pruebas, en los valores de conductancia hidráulica. Tampoco se pudo establecer una relación inversa entre la fuerza de aplicación de un adhesivo en forma activa con un aplicador mejorado y la conductancia hidráulica, por lo cual no se aconseja el uso de dicho instrumento(AU)

ABSTRACT Introduction: Dentin permeability is defined as the passage of fluids, ions, particles, molecules and bacteria through the dentin under certain conditions. Objective: Determine the effect of the active application of a dentin adhesive with an improved applicator on human dentin hydraulic conductance in vitro. Methods: An in vitro experimental study was conducted of 40 caries-free third molars with an indication of exodontia from healthy patients aged 15-30 years, prior informed consent. The molars were cleaned, disinfected and preserved to be included in epoxy resin blocks. Cross-sectional cuts were then made to obtain dentin discs 1.5 mm thick and 25 mm in diameter. These were divided into two 20-unit groups, were subjected to etching with 37 percent orthophosphoric acid, and were washed and dried. On a precision scale photopolymerizable dentin adhesive was applied, recording the force exerted. Application was performed with a Microbrush applicator in Group 1 and with an improved dedicated applicator in Group 2. The samples were then placed in a diffusion chamber to determine flow rate and subsequently estimate hydraulic conductance, thus obtaining information about dentin permeability. Results: Results were slightly lower in Group 2, but they displayed normal distribution. Conclusions: Statistical analysis with various tests did not find any significant differences in hydraulic conductance values, nor could an inverse relation be established between the force of active application of an adhesive with an improved applicator and hydraulic conductance. Therefore, use of that instrument is not advised(AU)