Efeito de diferentes agentes de limpeza cavitária sobre o selamento marginal em cavidades classe II sob microscopia óptica e microscopia eletrônica de varredura

Abstract

This study evaluated the in vitro microleakage in class II restorations with composite nanoparticles using five different cleaning agents cavity by means of optical microscopy and scanning electron microscopy. Twenty-five human molars were used, which were performed in the vertical slot type cavities, mesial and distal gingival ending below the cemento-enamel junction. The teeth were randomly divided into five groups, according to the cleaning agent used (n = 10): control group - use of air jet / water; Group I - solution of phosphoric acid 10%, Group II - solution citric acid 10%, Group III - Chlorhexidine Solution 2% and Group IV - EDTA solution to 17%. The cavities were restored with conventional adhesive system of three steps Scotchbond Multi-purpose composite nanoparticle eresina both Z350 3M ESPE. The specimens were subjected to 5000 cycles with temperatures of 5 º C + 2 º C and 55 º C + 2 º C in alternating baths of 30 seconds each. Subsequently, the specimens were immersed for 24 hours in a solution of ammoniacal silver nitrate, then in radiographic developer for 8 hours under fluorescent light. Were sectioned mesio-distal to evaluate the microleakage in optical microscope and scanning electron microscope by means of scores. The results were statistically analyzed by the non-parametric Kruskal Wallis analysis of variance and the Mann-Whitney test with significance level of 5%. It can be concluded that the substance EDTA demineralization was cleaning agent cavity that had the greatest number of scores 3, lower right occorrência microinfiltraçãol when compared to the other substances tested. Citric acid 10% had worse outcomes, and therefore not its intended use as a cleaning agent cavity. Relative to 10% phosphoric acid, Chlorhexidine 2% and distilled water, they do not have statistically significant differences. Thus, before the results can not be said that the demineralizing substances are more effective than non demineralization, when evaluated in light microscopy and scanning electron microscopy.