Avaliação da limpeza da superfície dentinária apical após a remoção de diferentes associações de hidróxido de cálcio

Abstract

To evaluate the apical dentine surface, after the removal of various calcium hydroxide [Ca(OH)2] pastes, sixty-eight single-rooted teeth were used, instrumented using the step-back technique. The root canals were irrigated by 5-ml of a (1%) sodium hypochlorite (NaOCl), followed by a 10-ml (17%) ethylene diamine tatracetic acid (EDTA-T) final rinse. The samples were randomly divided into four groups (n=15), on the basis of the calcium hydroxide paste: Ca(OH)2 with (0.2%) chlorhexidine solution (Group 1); with propyleneglycol (Group 2); ciprofloxacin, metronidazole and distilled water (Group 3); ciprofloxacin, metronidazole and propyleneglycol (Group 4). The negative control teeth (n=4) had not been filled with Ca(OH)2, and the positive control (n=4) the removal was not made. The samples were stored at 37ºC - 100% relative humidity for 21 days. The medicaments were removed using: 5-ml 1% NaOCl irrigation; instrumentation using the master apical file in a circumferential filing action; 5-ml 1% NaOCl; patency with K-file #10; ultrasonic instrumentation with K-file #15; and 10-ml 17% EDTA-T. The specimens were analyzed using a scaning eletron microscope, and Kruskal-Wallis (α = 5%) statistical test shows that were not difference between the experimental groups comparing Ca(OH)2 removal (p = 0.0951). Qui-square test (α = 5%) indicated a predominance of Ca(OH)2 obstructing dental tubules. After chemical analysis (energy dispersive X-ray microanalyzer EDX), and statistically evaluated using analysis of variance and Tukey test (α = 5%), indicates difference comparing calcium (Ca) in group 1 and 4. On the basis of the applied methodology, its concluded, independently of the vehicle, apical dentine surface equally remains cover by Ca (OH)2.