ABSTRACT
El objetivo de este estudio fue valorar la microfiltración del ionómero de vidrio mejorado (Ketac Molar Easymix ®) con o sin el uso de acondicionador. Para lograr éste, se seleccionaron 40 terceros molares extraídos, limpios e hidratados. Se formaron dos grupos de 20 muestras de forma aleatoria, a los cuales se les realizó profilaxis y cavidades de clase V sobre la cara vestibular. Al grupo A se le colocó un acondicionador de ácido poliacrílico como indica el fabricante, antes del ionómero, y al grupo B se le colocó el ionómero directamente. Las muestras se sometieron a un proceso de termociclado y fueron sumergidas en azul de metileno al 1%, durante 30 minutos. Cada molar fue seccionado con disco de carburo, con cortes longitudinales en el centro de la preparación. Cada sección fue examinada minuciosamente al microscopio. Se calificaron las muestras y se obtuvo que el promedio de microfiltración para el grupo A fue de 2.06% y para el grupo B fue de 1.84%, sin representar diferencias significativas. Por lo que se concluye, con que no existen diferencias significativas en colocar acondicionador en este tipo de cavidades y con este material en particular.
The aim of the present study was to assess microleakage experienced by improved glass ionomer (Ketac Molar Easymix ®) with and without use of conditioner. In order to conduct this study, 40 third molars were used. Molars had previously been extracted, cleansed and hydrated. Two 20 randomly selected sample groups were established. Samples were subjected to prophylaxis and class V cavities were created on the vestibular (labial) surface of the teeth. Before ionomer application, and according to manufacturer's instructions, group A received a polyacrylic acid conditioner, whereas group B received direct ionomer application. All samples were subjected to a thermo-cycling process and then were immersed in a 1% methylene blue solution for 30 minutes. All molars were sectioned with carbide burr executing longitudinal cuts at the preparation's center. Each section was carefully examined under the microscope. Samples were rated and the following was observed: microleakage, for group A was 2.06% and for group B 1.84% which did not represent statistically significant differences. It can therefore be concluded that application of conditioner in this type of cavities and with this particular material does not cause statistically significant differences.
ABSTRACT
Enzyme stability is critical in biotechnology, pharmaceutical and cosmetic industries. Investigations on this subject have drawn attention because of its practical application. Bromelain is a thiol-endopeptidase, obtained from pineapple (Ananas comosus), known for its clinical and therapeutic applications, particularly to selective burn debridement and improvement of antibiotic action and anti-inflammatory activities. To date, the use of bromelain in pharmacological or industrial applications is limited, due to commercial availability, costs, and sensitivity to pH and temperature. Therefore, a better understanding of enzyme stability would be of great interest. The aim of this study was to evaluate bromelain activity and stability in several pH (2.0 to 8.0) and in polyethylene glycol and polyacrylic acid solutions. We observed that bromelain was able to maintain its stability at pH 5.0 for the temperatures studied. PEG solutions increased bromelain stability, but PAA solutions had the opposite effect.
Estabilidade de enzimas é uma questão fundamental em indústrias biotecnológicas, farmacêuticas e cosméticas. As investigações sobre o assunto têm chamado a atenção por sua aplicação prática. A bromelina é uma tiol-endopeptidase, obtida a partir do abacaxi (Ananas comosus). É conhecida por suas aplicações clínicas e terapêuticas, especialmente para desbridamento seletivo de queimaduras, melhoria de ações antibiótica e de atividades anti-inflamatórias. Até o momento, a utilização da bromelina em aplicações farmacológicas industriais é limitada, devido à disponibilidade comercial, os custos, a sensibilidade ao pH e temperatura. Portanto, a maior compreensão da estabilidade desta enzima seria de grande interesse. O objetivo deste estudo foi avaliar a estabilidade da atividade da bromelina em vários pH (2,0 a 8,0) e em soluções de polietilenoglicol e de ácido poliacrílico. Observamos que a bromelina foi capaz de manter a sua estabilidade em pH 5.0, em todas as temperaturas estudadas. Soluções de PEG aumentaram a estabilidade da bromelina, enquanto que soluções de PAA obtiveram efeito oposto.
Subject(s)
Bromelains/analysis , Alkalinization/adverse effects , Polyethylene Glycols/analysis , Enzyme Stability , EnzymesABSTRACT
The glass ionomers are one the new materials used in dentistry, they are composed of glass particies and carboxilic acid providing adhesive properties as well as very low pulpar irritation. The term ionomer is applied to those polimers that are linked among them by ionic reactions. The offer special properties like: more strength, transparency, durability, good sealing, F liberation, affinity for dental structures. There are several types of glass ionomers (I, II, III, IV, V). This paper will deal with their own characteristics, indications and manipulation.