Comparison of the efficiency of phytic acid, citric acid and edta in the removal of calcium hydroxide from root canals: Electron microscope study

Aim The aim of this study is to evaluate the removal efficiency of calcium hydroxide, which is used as a canal medicament, from the canal by using phytic acid, citric acid and EDTA as the final irrigation agent, using scanning electron microscopy. Material and Metod In our study, 51 single root and canal mandibular premolar teeth, which were extracted for periodontal or orthodontic reasons, were used. Before starting the study, the crowns of all teeth were cut near the enamel-cementum junction and a standard length of 14 mm was obtained. After the working length was determined, the root canals were prepared mechanically with the Reciproc R50 (VDW, Munich, Germany) file system. During the mechanical preparation, after 6 ml of 5% NaOCl and 17% EDTA were applied with an irrigation needle, final irrigation of all channels was performed with distilled water. Three teeth were divided into positive and three negative control groups. The remaining teeth were randomly divided into groups (n=15) as Group 1: 17% EDTA, Group 2: 20% citric acid, and Group 3: 1% phytic acid. After the root canals were dried with paper cones, syringe type calcium hydroxide paste was used, and the paste was sent to the canal until it overflowed from the coronal. In all groups, after Teflon tape was placed in the canal entrance cavities, the canal entrance cavities were closed with 3 mm thick Cavit (3M, Seefeld, Almanya). The samples were kept in an oven for 1 week. After the temporary filling of the teeth was removed, ultrasonic activation (Eighteeth Ultra X-Ultrasonic Activator, Changzhou, China) and chelating agents were each applied in a volume of 5 ml for 60 seconds. To ensure neutralization, irrigation of the teeth with distilled water was completed and dried with paper cones. The coronal, middle and apical parts of the teeth were visualized under x2000 magnification under a scanning electron microscope. The Kruskal Wallis H test was used for the statistical measurement of the obtained images. In case of significant difference in comparisons with more than two groups, the groups with significant differences between them were determined with the help of Post-Hoc tests (Mann Whitney U test with Bonferroni correction). Result When the chelation agent groups used and the calcium hydroxide removal efficiency were evaluated, a statistically significant relationship was found. No significant difference was found between Group 1 (EDTA) and Group 2 (Citric acid) (p=0.999; p>0.05). However, a significant difference was found between Group 1 and Group 3 (Phytic acid), and between Group 2 and Group 3 (p<0.05). Group 1 and Group 2 removed calcium hydroxide from root canals more effectively than Group 3. Although there was no statistically significant difference between the calcium hydroxide residues in the root canals according to the section levels (coronal, middle, apical), the root section with the least residues among the sections was the coronal third. Conclusions None of the chelating agents used could completely remove calcium hydroxide from the channel. More studies are needed on the use of phytic acid in endodontics. If EDTA and citric acid are used with passive ultrasonic activation with appropriate methods, it gives positive results.