Siragusa, MarthaRacciatti, Gabriela C2010-04-132010-04-132002-08Siragusa, Martha y Racciatti, Gabriela. Last generations endodontic instrument. A study of their efficacy and apical shapping. Electronic Journal of Endodontics Rosario [Online], Volumen 1 Número 1 [agosto 2002]. Disponible en: http://www.endojournal.com.ar/journal/index.php/ejer/article/view/2. ISSN 1666-6143.1666-6143http://hdl.handle.net/2133/1373One of the aims of surgical preparation is to remove pulp tissue and shape the root canal to access the apical foramen. The aim of the present study was to evaluate the efficacy of manual and rotary instruments versus stainless steel instruments in cleaning and shaping. Sixty-five lower premolars with curvatures that did not exceed 25° were assigned to 6 groups. Coronal-apical preparation techniques were employed. The samples were longitudinally abraded and observed in a stereomicroscope at x40 magnification and by SEM. The best results were observed in Groups 6 (rotary Pro File) and 4 (Pro File 29) as compared to Group 2 (stainless steel). The present results reveal that very few of the surgical preparations achieved complete removal of tissues, debris and microorganisms. It is difficult to guarantee complete removal, particularly in clinical practice.engopenAccessInstrumentsShappingApicalarticle