A comparative evaluation of removal of gutta percha using two retreatment file system: An in vitro study

Abstract

A comparative evaluation of the efficiency of two retreatment file systems in removing Gutta-percha from the root canals.Forty mandibular premolar teeth with single roots were specifically collected and decoronated with diamond disc so that the root lengths were standardized.Working length (WL) determination was done and root canal preparation done using Hyflex CM rotary files which was followed with meticulous irrigation and obturation was performed with gutta-percha, by the lateral condensation technique.AH-Plus sealer was used. The specimens were then divided in a random manner into two groups, in which retreatment was performed using two retreatment systems, Mtwo and REndo. These were further subdivided into two subgroups groups, i.e. one group using root canal solvent and another without solvent. Retreatment will be considered accomplished when gutta-percha was fully removed from the canal and none could be observed on the retreatment instruments and the same was confirmed radiographically. Longitudinally sectioning was done to split the root in to two halves-Mesial & Distal and was observed for the remnants under scanning electron microscope with 40x and 100x magnification. Photographs of the specimens were taken using a digital camera and the area of the remaining obturating material was determined using the AutoCAD16 software.: The area of remaining guttapercha in mesial and distal half for all the samples were evaluated using the Autocad software(Version 2016) and the mean as well as standard deviation of each group were used for statistical analysis (SPSS 22.00 for windows; SPSS inc, Chicago, USA).Statistical analysis was done using factorial ANOVA and Tukey HSD Post Hoc test. Difference between two groups was determined using student t-test and the level of significance was set at p < 0.05.The results revealed that Mtwo R file system was found to be a more efficient rotary system for endodontic retreatment when compared to REndo(p<0.05) and use of solvent acts as an adjuct for retreatment in both file systems (p<0.05).