摘要：The preparation for the endodontic treatment is proper cleaning and shaping the root canal system, and always keep its original shape. After the preparation, must be obtained through uniform and tapered with an apical stop, allowing a tight seal when the seal. It must take into account the difficulty of achieving satisfactory results especially in curved canals and calcified due to the complexity of these, the implemented techniques, and instrumentation suitable for the preparation of pipes have been many in order to minimize errors during preparation. But any technique or instrument itself ideal in preventing these errors, it is necessary to comply with some basic principles for the preparation of these channels, such as proper preparation coronal, the continued use of irrigants and chelating agents, maintenance of the permeability, filing anticurvatura and double taper. The incorrectness of these principles leads to errors which hinder the success of endodontic treatment. The progress of science and the advent of nickel-titanium instrument, it has been facilitating both root canal treatment is no longer considered previously attributed to him was a difficult procedure, the important thing to predict the orientation and anatomy through before using or instrumental techniques, since an error in them will lead to treatment failure. Keywords: development, calcification, root canal.
