Assessment of the Antibacterial Effect and Post-operative Pain Following Various Techniques of Intracanal Heating of Sodium Hypochlorite: A Randomized Clinical Trial

Root canal treatment success depends on the removal of necrotic and vital pulp tissues and bacteria and bacterial byproducts from the root canal system.

Mechanical cleansing and removal of necrotic or vital pulp tissue lead to the formation of a layer of debris called " Smear layer," which is made of organic and inorganic substances that should be removed from the root canal system with the help of irrigants.

The presence of complex anatomy like isthmi and anastomoses makes chemical cleansing of the root canal system difficult because they are filled with the smear layer.

The ideal features of root canal irrigants include cleansing, lubrication of endodontic instruments and root canal system, dissolution of inorganic and organic tissues, antimicrobial properties, absence of cytotoxicity without alteration of dental microstructure. Sodium hypochlorite (NaOCl) has been the most widely used irrigant in endodontics due to its antimicrobial and tissue-dissolving action.

Due to the presence of complex anatomy inside the root canal system, activation of irrigation is essential to improve the cleaning of such a complex system. Ultrasonic activation is presently the most popular method for activation of irrigation. It delivers the irrigant farther into areas of the root canal system untouched by instruments, and it improves the mechanical cleaning by increasing the wall shear stress.