comparison of different activation methods to remove calcium hydroxide and calcium hydroxide nanoparticles from canal walls : an in-vitro study

Abstract

Introduction: Calcium hydroxide and nano calcium hydroxide are two types of intra canal medicament which are used for elimination of pathogenic microbes. The aim of this study is to evaluate the efficacy on NaOCl 1% with different irrigation systems on removing calcium hydroxide and nano calcium hydroxide. Materials and methods: 142 extracted single-rooted teeth were shaped and a standard groove on the apical third of the root canal surface was prepared. Samples were randomly devided into two groups according to the intra canal medicament and these two groups were devided into three subgroups based on the activation technique. In group C1 (n=23) the root canals were filled with calcium hydroxide and that was removed using conventional irrigation with NaOCl whereas in group N1 (n=23) the root canals were filled with nano calcium hydroxide and that was removed using conventional irrigation. Group C2 (n=23) and group N2 ( n=23) received sonic activation with the same intra canal medicament as group C1 and N1 respectively. In group C3 (n=23) passive ultrasonic irrigation (PUI) was used whith NaOCl for removing calcium hydroxide while in group N3 ( n=23) the intra canal medicament was nano calcium hydroxide and it was removed by NaOCl and activated by PUI. The amount of remaining calcium hydroxide and nano calcium hydroxide in the artificial grooves were evaluated under a stereo microscope.

Results: PUI is the most efficent method when the intraca medicine is nano CaOH. PUI is more efficent than two other methods in both intaracanal medicine . There was not significant difference between manual and sonic in both intracanal medicine .