The goal of endodontic therapy is to prevent the development of inflammatory changes in the pulp with consequent periapical lesions and to achieve the conditions for the healing ofalready present lesions. This means removing the infected contents and a properinstrumentation of the root canal, disinfection and final filling to the internal foramen. Rootcanal processing instruments are divided into manual and mechanical. Hand instruments aremade of stainless steel, while, in contrast to them, the introduction of NiTi alloy in dentistryallowed a simpler and more accurate instrumentation of root canals. NiTi alloys have certainproperties such as memory capability and superelasticity, which makes them an indispensablematerial for the production of machine instruments. Nowadays, there are systems that usereciprocal movements, rotational movements, a combination of reciprocal and rotationalmovements, and vibrational movements. Almost all mechanical instrumentation techniquesinvolve instrumentation of the canal using the "crown-down" technique, which allowssufficient coronary expansion, which reduces the contact of the instrument in the canal andreduces torsional forces. Each of these systems has its advantages and disadvantages, but nonehas completely overcome all the difficulties we encounter in processing root canals