Evaluation and comparison of smear layer removal potency of three different irrigation regimes – A stereomicroscopic and scanning electron microscopic study

Background: Irrigation plays a pivotal role in pulp therapy owing to its flushing action and removal of the smear layer which if present prevents penetration of medicaments and sealers into the dentinal tubules. Aim: This study aims to evaluate and compare the smear layer removal potency of three commercial Irrigating agents. Materials and Methods: Single rooted 30 teeth were selected, decoronated, and randomly divided into three groups according to the irrigation regime to be used (Group I − 5% sodium hypochlorite [NaOCl] + ethylenediaminetetraacetic acid [EDTA], Group II – Chloraxid Gel + EDTA, Group III – Tween Kleen + 3% NaOCl). After recommended biomechanical preparation and irrigation, teeth were stained with 1% methylene blue dye for 24 h and sectioned in 2 halves. Stereomicroscopy was used to assess dye penetration and scanning electron microscope (SEM) analysis was done to detect dentinal surface changes. Data were analyzed using one-way ANOVA test and Tukey honestly significant difference test by statistical software SPSS version 20.0. Results: The highest dye penetration exhibiting smear layer removal for the apical third was seen in Group II (44.78) and for the middle third in Group I (64.73) which was statistically significant. SEM analysis showed maximum dentinal tubules visibility and patency in Group I and minimum in Group III. Conclusion: Newer irrigating materials (1-hydroxyethylidene-1, 1-bisphosphonate) exhibited weak potency for smear layer removal. The sequential use of gold standard NaOCl + EDTA gave satisfactory results, however, in apical third NaOCl Gel + EDTA was found to be more effective. Therefore, it can be prudent to use NaOCl Gels as a safer alternative to conventional means.