Radwa O. Ibrahem, Rania Ahmed Helmy Salama And Abdelhady Mohamed Amin,

ABSTRACT
BACKGROUND: Proper Irrigation Of The Root Canal Is A Mandatory Step For A Successful Endodontic Treatment. Up To The Moment, Sodium Hypochlorite Is Considered The Gold Standard Of Endodontic Irrigation. Nevertheless, Safety Concerns Have Raised Regarding Its Use. 99% Ethanol Is A Strong Antiseptic Solution With A Potent Antimicrobial Activity. However, Its Use In Endodontic Irrigation Has Never Been Tested METHODS: The Antimicrobial Activity Was Measured Using The Agar Dilution Method. Twelve Single-rooted Human Permanent Incisors Or Premolars Teeth Were Included In The Study And Randomly Divided Into Two Groups: (Group1: 2.5% NaOCl And Group 2: 99% Ethanol). The Teeth Were Decoronated And The Root Samples Were Autoclaved To Ensure Absence Of Any Microorganisms. Each Root Canal Was Then Inoculated With A Standardized Strain Of Enterococcus Faecalis Suspension (ATCC 29212) Followed By Incubation Of The Root Samples At 37�C For 48 Hours. The Number Of Colony Forming Units After Inoculation Was Manually Counted. The Root Canals Were Then Cleaned And Shaped Using The Traditional Step-back Technique Coupled With Application Of The Corresponding Irrigant For Each Group. The Number Of Colony Forming Units After Irrigation Was Manually Counted And Compared With That Obtained Before Irrigant Application. The Data Were Listed As Mean And Standard Deviation. One Way ANOVA Was Used To Test The Effect Of Group On Antimicrobial Activity. Duncan Post-Hoc Multiple Comparisons At P�0.05 Was Used For Means Comparison. RESULTS: All Of The Samples Obtained After Inoculation Of The Tested Microorganism For 48 Hours Revealed Uncountable Colony Forming Units. Following Application Of The Corresponding Irrigant For Each Group, Both Groups Revealed A Decrease In Bacterial Count With No Statistically Significant Difference (P � 0.05) Between The Two Groups. CONCLUSION: 99% Ethanol Has An Antimicrobial Effect Against E. Faecalis Comparable To That Of 2.5% NaOCl. However, Further Preclinical And Clinical Trials Are Needed To Evaluate Biocompatibility And Safety Before 99% Ethanol Can Be Recommended As An Intracanal Irrigant.