Smear layer removal efficacy of different irrigating solutions: a comparative scanning electron microscope evaluation

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Smear layer removal is crucial for effective endodontic treatment.
• Various irrigating solutions are used to remove the smear layer, but their efficacy can vary.

Purpose of the Study:

• To comparatively evaluate the smear layer removal efficacy of different irrigating solutions in the apical third of root canals.
• To assess 2.5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl, and 1% tetracycline hydrochloride (HCl) with 2.5% NaOCl.

Main Methods:

• An in vitro material science study was conducted using 75 single-rooted maxillary central incisor teeth.
• Teeth underwent standardized root canal instrumentation and were divided into five groups: normal saline, 2.5% NaOCl, 17% EDTA + 2.5% NaOCl, 10% citric acid + 2.5% NaOCl, and 1% tetracycline HCl + 2.5% NaOCl.
• Scanning electron microscopy was used to evaluate smear layer removal in the apical third.

Main Results:

• No statistically significant difference was observed in smear layer removal efficacy among the groups using 2.5% NaOCl, 17% EDTA + 2.5% NaOCl, 10% citric acid + 2.5% NaOCl, and 1% tetracycline HCl + 2.5% NaOCl in the apical third.
• Normal saline showed less effective smear layer removal compared to the other tested solutions.

Conclusions:

• Citric acid and tetracycline hydrochloride can serve as effective alternatives to EDTA for smear layer removal in endodontic treatment.
• These findings support the use of citric acid and tetracycline hydrochloride in endodontic irrigation protocols for optimal cleaning of root canals.