Irrigation is an integral part of Endodontic treatment and sodium hypochlorite is the irrigant of choice. Sodium hypocholrite in different concentrations has shown to decrease the hardness of dentine which can lead to many detrimental effects. This book focuses on a new strength namely 'edge strength of dentine' showing what effect different commonly used concentrations of sodium hypocholrite can have on it and thus help predict the concept of marginal integrity of the restoration /root filling to this affected edge of dentine. The book shall help giving an answer to many readers of the concept of leakage through this microchannel.