Análise do pH, da liberação de íons cálcio e da capacidade seladora de cimentos contendo hidróxido de cálcio e MTA utilizados em obturação retrógrada

Abstract

Novos materiais retrobturadores sao propostos, destacando-se os cimentos que contem hidroxido de calcio ou a base de trioxido mineral agregado (MTA). O cimento endodontico Sealer 26 e o MTA sao indicados em obturacoes retrogradas. Recentemente, o cimento a base de MTA denominado Endo CPM Sealer foi proposto. Assim, o objetivo deste estudo foi avaliar a liberacao de ions calcio e o pH proporcionado por alguns cimentos utilizados em obturacao retrograda: 1- Sealer 26, 2- MTA, 3- Endo CPM Sealer e 4– Endo CPM Sealer em maior proporcao po/liquido e 5- Oxido de zinco e eugenol (OZE). Para analise do pH e calcio, os materiais foram inseridos em tubos de polietileno medindo 1,5 mm de diametro e 10 mm de comprimento e imersos em frascos com 10 mL de agua destilada. As avaliacoes foram realizadas nos periodos de 3, 6, 12, 24 e 48 horas, 7, 14 e 28 dias. Os tubos foram transferidos apos cada periodo experimental em novos frascos contendo 10 mL de agua destilada. A mensuracao do pH das solucoes foi realizada por meio de pHmetro digital. A liberacao de calcio foi estudada por meio da espectrofotometria de absorcao atomica. Tambem foi avaliada a capacidade seladora dos mesmos materiais em obturações retrogradas. Foram utilizados dentes unirradiculados humanos, cujos canais radiculares foram instrumentados e obturados com cones de guta-percha e cimento de oxido de zinco e eugenol. Apos a seccao de 3 mm apicais, cavidades retrogradas com 3 mm de profundidade foram preparadas com auxilio de pontas de ultra-som. Os dentes foram divididos em cinco grupos experimentais, de acordo com o material utilizado para obturacao retrograda (n=12) e dois grupos controles (n=3), sendo um sem material retrobturador e outro com impermeabilizacao total incluindo a superficie apical. Os dentes foram imersos em corante Rodamina B a 0,2% por...

New root-end filling materials are proposed. The most important are that containing calcium hydroxide, or based on mineral trioxide aggregate (MTA). The endodontic sealers Sealer 26 and MTA are used in retrogade obturation. Recently, the cement-based MTA called Endo CPM Sealer has been proposed. The aim of this study was to evaluate the release of calcium ions and pH provided by some materials used in retrograde filling: 1 - Sealer 26, 2 - MTA, 3 - Endo CPM Sealer and 4 - Endo CPM Sealer in greater proportion powder / liquid and 5 - Zinc oxide and eugenol (ZOE). For analysis of pH and calcium, the materials were put in tubes of polyethylene measuring 1.5 mm in diameter and 10 mm in length and immersed in bottles with 10 mL of distilled water. Evaluations were performed in periods of 3, 6, 12, 24 and 48 hours, 7, 14 and 28 days. The tubes were transferred after each experimental period in new bottles containing 10 mL of distilled water. The measurement of pH of the solutions was done through a digital pHmeter. The release of calcium was studied by means of atomic absorption spectrophotometry. It was also evaluated the sealing ability of the same materials in retrograde obturations. One rooted human teeth were used, whose root canals were instrumented and fillied with gutta-percha cones and zinc oxide and eugenol sealer. After the section of 3 mm apical, retrograde cavities with 3 mm depth were prepared using ultrasound tips. The teeth were divided into five experimental groups, according to the material used for retrograde filling (n = 12) and two control groups (n = 3), one without material and the other with total impermeabilization including apical surface. The teeth were immersed in a Rodamina B 0.2% dye for 48 hours in vacuum environment. After longitudinal section, digital images were obtained, which were analyzed in an... (Complete abstract click electronic access below)