Despite the fact that biomechanical preparation of root canals can be challenging for practitioners, endodontic treatment has reached high success rates thanks to the development of instrumentation techniques (e.g. Reciprocating), technology, and materials (M-wire NiTi). In most cases, the reciprocating techniques require only one hand file followed by a single reciprocating file to completely shape the canal. This is a quicker method for instrumentation because it is not necessary to create the glide path. Due to the centring ability of reciprocating technique and the design of reciprocating instruments and their cutting ability, the instrument will follow the existing natural path of the root canal. By using the one of reciprocating motion techniques, the endodontic treatment can be performed in a shorter period of time then by using conventional methods and the instruments and will respect the original canal curvature. The better maintenance of original shape may lead to a better prognosis. The reciprocating movement promote the extended cyclic fatigue life of the NiTi instrument and we can expect a very low incidence of instrument fractures and deformations in comparison with conventional rotation. When the reciprocating instruments bind in the canal, they do not fracture because they never rotate past their specific angle of fracture. The single file method is as effective as the multiple rotary or manual techniques systems removing microorganisms and their endotoxins from the root canal spaces but will not leave bacteria-free root canals. Because of this, mechanical preparation of the root canal must be assisted by intense and activated irrigation. On the other hand, it seems that reciprocating, single file techniques extrude fewer bacteria apically during instrumentation than the conventional multifile rotary system. The reciprocating instrument used in a clockwise and counter clockwise movement can offer several major advantages from the patient's point of view: the single use of instruments, the elimination of possible prion cross-contamination and reduced instrument fatigue which makes the instruments safer than using hand and rotary reamers and files.