Mechanical instrumentation alone will not completely eliminate bacteria from a root canal system (Baker et al 1975).With both current nickel titanium instrumentation systems and traditional stainless steel hand instruments almost half of the root canal walls are left unprepared. The complexity of root canal morphology presents a challenging objective to the endodontic community. These complexities hamper the ability to thoroughly achieve pulp cavity disinfection. Microorganisms located in the ramifications, deltas, irregularities and dentinal tubules may sometimes be unaffected by endodontic disinfection procedures. This ascertains the importance of chemomechanical root canal preparation.

DR TAPAN KUMAR MANDALBDS ( Aurobindo college of dentistry,Indore )MDS ( Institute of dental science,Bareilly )currently working as a senior lecturer in Hazaribag college of dental sciences and hospital