Avaliação da radiopacidade de resinas compostas por meio de imagens digitais e convencionais digitalizadas antes e depois de envelhecimento artificial

Abstract

The aim of this study was to evaluate the radiopacity of five composite resins. Five samples of each composite in thickness 2, 3 and 5mm were made. A sample of each resin at a certain thickness, two slices of enamel and dentin, an aluminum step wedge and a blade of lead were radiographed with conventional film and CCD sensor. The conventional films were digitized. The resin samples were subjected to artificial aging by thermocycling and were radiographed at a second time. The optical densities of the images obtained were evaluated by the software Adobe Photoshop® CS4. The results were submitted to statistical analysis, by ANOVA - Tukey Post Hoc Test, Student’s t test for paired samples and Student’s t test for independent samples. The level of radiopacity was variable, and the composite resin Evolu-X® was the most radiopaque and Filtek®P90 was the least radiopaque in the direct digital system. The composite resins Filtek® Z350, Filtek® Z250, Evolu-X® and Charisma® did not differ in conventional system. The composite resins Filtek® P90, Filtek® Z350 and Charisma® presented significant reductions in radiopacity mean values when subjected to artificial aging and evaluated by the direct digital system, but there was no statistically significant decrease in radiopacity of all the composite resins studied when evaluated by conventional system. The radiopacity values increased on rising the thickness of the samples. The composite resins were satisfactory for clinical use when evaluated by both methods, before and after artificial aging.