Comparative Analyses of Smear Layer Removal Using Four Different Irrigant Solutions in the Primary Root Canals - A Scanning Electron Microscopic Study.

INTRODUCTION: A clinician's path to success is a clean root canal system with three dimensional seal. Mechanical instrumentation of root canals alone leaves behind a smear layer covering the dentinal walls. Instrumentation must always be supported by use of irrigants which are considered as an essential prerequisite for root canal debridement.

AIM: The aim of this in vitro study was to compare the efficacy of four irrigating solutions in removing the smear layer in primary root canals after hand instrumentation.

MATERIALS AND METHODS: A total number of 40 human primary incisors were decoronated and split longitudinally. The specimens were divided randomly into four groups (n=10): Group I: 5.25% Sodium Hypochloride (NaOCl), Group II: 6% citric acid solution, Group III: smear clear and Group IV: 0.2% chitosan. Scanning electron microscopic analysis was performed to assess the presence or absence of smear layer at the coronal, middle and the apical portion of each canal. The data was analysed using Stastical Package For Social Sciences (SPSS) version 19.0 Armonk, NY IBM Corp soft ware.

RESULTS: The pictures from the scanning electron microscopy showed that Group II exhibited better efficacy in removing smear layer without altering the normal dentinal structures with lowest mean scores (p<0.001) followed by Group III, Group IV and Group I. The presence of debris was more evident in the apical third rather than in the middle and the coronal part of the root canal.

CONCLUSION: A 6% citric acid removed the smear layer more efficiently than other test irrigants in primary root canals.