Effect of 17% EDTA on removal of canal wall smear layer and calcium hydroxide dressing: part II

Abstract

Objective the aim of this study was to evaluate, by scanning electron microscopy, the effectiveness of 17% EDTA on removal of canal wall smear layer and calcium hydroxide dressing in different thirds of root canal. MethodsTtwenty-four premolars were instrumented in the cervical and middle thirds using Gates-Glidden drills. At the working length, the canal was widened up to # 35 file, followed by scaling up to file # 50. After instrumentation, the teeth were divided into four groups according to the treatment received: GI -irrigation performed with 5 ml of NaOCl 2.5 % ; GII -irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by irrigation with 5 ml of 2.5% NaOCl ; GIII -irrigation with 5 ml of NaOCl 2.5% , drying , application of temporary dressing of Ca (OH ) 2 with propylene glycol and sealing. After 5 days , removing the sealing irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by a final flush with 5 ml of 2.5% NaOCl ; GIV -irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15 , followed by irrigation with 5 ml of 2.5% NaOCl , drying and after use of the medication in Ca (OH ) 2 with the sealing and propylene glycol which was removed after 5 days performing the irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by using 5 ml 2.5% NaOCl . Next, the teeth were prepared and taken to the scanning electron microscope . Results The images revealed: Group I -a marked presence of smear layer in all three thirds, Group II -removal of almost all of the smear layer in the cervical third and removal of large quantity in the middle third, whereas in the apical third a large quantity of smear layer still remained however, in comparison with the other groups, this was shown to be cleaner; Group III -in the three thirds, the presence of smear layer was observed, which was shown to be much less compacted than that observed in Group 1; Group IV-in all the thirds there was reduction of smear layer and Ca(OH) 2 -based medication, and presence of several unobstructed dentinal tubules could be observed, demonstrating the second best result observed. ConclusionIt could be concluded that the use of 17% EDTA favored removal of the smear layer and intracanal medication residues in all thirds of the root canal. Indexing terms: Calcium hydroxide. Dental pulp cavity. Edetic acid. Smear layer. RESUMO ObjetivoAvaliar através de Microscopia Eletrônica de Varredura, a eficácia do EDTA a 17% na remoção da smear layer e da medicação de hidróxido de cálcio nos diferentes terços do canal radicular. MétodosVinte e quatro pré-molares foram instrumentados nos terços cervical e médio utilizando-se brocas Gates-Glidden. No comprimento de trabalho realizou-se o alargamento até a lima #35 seguido do escalonamento até a lima #50. Após, os dentes foram divididos em quatro grupos de acordo com o tratamento recebido: GI -irrigação reali...

A scanning electron microscope evaluation of efficacy of sodium hypochlorite and Allium sativum in smear layer removal in root canals with the use of modified evacuation system: An ex vivo study

“…This may be explained as being due to the irrigation system having attained the apical third less efficiently, as a result of the size of the aspiration needle and needle tip not reaching the complete extension of the working length of the root canal, thus not allowing the irrigant solutions to achieve the desired result. [ 20 ] These limitations have also been pointed out by Pereira. [ 21 ] In the apical thirds of the specimen, the groups with MES showed the presence of loose, scattered clusters of debris whereas the groups without MES showed the presence of debris that adhered to the dentinal walls.…”