Estudo da sorção e solubilidade em água de resinas acrílicas polimerizadas pelas técnicas de microondas, convencional, pressão e calor

Abstract

The objective of this work was to evaluate the advantages and disadvantages of three polymerization techniques for denture base resins: microwave energy (M), conventional water bath (TC) and water bath under pressure (TP), in order to analyze the physical properties of sorption and solubility in water. There were made 30 samples of 66,0 ± 0,1 mm external diameter, 50,0 ± 0,1 mm internal diameter and 5,0 ± 0,5 mm thickness, divided in 10 TC, 10 TP and 10 M. In order to evaluate sorption, the samples were placed in the rack inside one desiccator containing freshly dried silica gel and stored in the oven at 37 ± 1 °C. Those samples were weighted regularly until all the masses became constant. With a digital caliper, three measures of the external and internal diameters and five of the thickness were made, and the samples were stored in deionized water at 37°C during 7 days ± 2 hours. After such time the samples were weighted and measured again, concluding the sorption test. The samples were inserted again into the desiccator with silica gel and stored in the oven to get to the reconditioned mass in order to test the solubility. The resins used for testing were Clássico® (TC and TP) and Ondacryl® (microwaves original - M) both of Clássico Artigos Odontológicos. Through the statistical analyzes of results there may be concluded that independently of the polymerization techniques (TC, TP and M) the samples showed sorption and solubility levels in accordance with the ISO specification nº 1567, and that the microwave technique has the advantage of time sparing in denture construction.