[Importance of apical instrumentation limit in the endodontic technique]

An improved knowledge of anatomy and psysiology of the apical radicular region has made mandatory a better classical endodontic technique concerning the apical limit of instrumentation, and has stressed the importance of a precise determination of the cemento-dentinal junction as the apical limit of canal obturation. On the basis of these orientations a clinical and radiographic study was carried out on 120 teeth extracted form humans, in which the frequency was determined of the excentric position of the cement conus with regard to the apex, and the distance between the cemento-dentinal junction and the apex. In 45 teeth in situ, with pulpar inflammation, gangrene and apical parodontitis a clinical and radiological appraisal was done of the cemento-dentinal junction, and evolution was followed after canal obturation.