Comparison of removal rate of smear layer by sodium hypochlorite and ozone gel with or without ultrasonic activation as cleaning agent of dental root canal

Abstract

Washing the canal causes the removal of tissues and debris that cannot be removed by instrumentation alone. Different detergents are used to remove residual debris and smear layer of dentin formed during mechanical preparation. The aim of this study was to compare the amount of smear layer removal by sodium hypochlorite and ultrasonically activated ozone gel as a root canal cleaning agent. Materials and methods The number of 130 mandibular single-canal teeth that meet the conditions for entering the study were selected. The teeth were kept in 0.9% normal saline solution immediately after extraction, cleaning, debridement and disinfection. In order to equalize the length of the roots and to achieve the standard length of 15 mm, the crowns of the teeth were cut perpendicularly to the longitudinal axis below the CEJ region. Dental samples were prepared using the BioRaCe rotary system with the crown-down technique in 5 groups. Group one (washing with sodium hypochlorite 5.25% and then washing with EDTA 17%, group two (washing with sodium hypochlorite 5.25% and activating with ultrasonic and then washing with EDTA 17%), group three (washing with Ozone gel and then washing with 17% EDTA, the fourth group was washing with ozone gel and activating with ultrasonic and then washing with 17% EDTA, the fifth group was washing with 17% EDTA. In all groups , rinsing was evenly spaced between each instrument during and after the instrument. Rinsing solutions were applied through a sterile 30-gauge ProRinse needle penetrating 1 to 2 mm from the WL. Two grooves on the buccal side and The lingual roots were created and divided into two halves in the area of the created grooves. In the next stage, one of the halves was randomly selected for extraction and SEM study. And the presence of the smear layer was checked in the coronal, middle and apical sections. SPSS software and Kruskal-Wallis and Mann-Whitney statistical tests were used for data analysis. Results The groups of sodium hypochlorite and sodium hypochlorite activated with ultrasonic increased smear removal compared to the control group. The groups of ozone and ozone gel activated by ultrasonic did not have a significant change in smear removal compared to the control group. Sodium hypochlorite activated by ultrasonic significantly had the lowest amount of smear removal among the studied groups. Conclusion Ozone gel and ultrasonically activated ozone gel are not substitutes for sodium hypochlorite.