The New 3rd Generation of Apex Locators
Arnaldo Castellucci
ABSTRACT
A much-discussed topic, which perhaps will always be disputed, is where to end the preparation – and thus, the obturation – of the root canal; in other words, what point to choose to determine the instrument’s working length. The correct determination of the working length (WL) is crucial for the success of the root canal treatment. WL is the distance from a coronal reference point to the point at which canal preparation and filling should terminate [1]. Thus, WL defines the deepest point within the root canal that the instruments may reach during the canal cleaning and shaping procedures, debris removing and sealing. A shorter WL may not provide a complete cleaning, leading to post-treatment inflammation and disease recurrence. On the other hand, if a longer WL is used to perform the root canal treatment the apical periodontal tissues can be damaged [2]. Several methods have been described to determine the working length in endodontic therapy: tactile, radiographic, electronic and the consistent drying point.
