ABSTRACT
Different methods and automated devices have been developed to accomplish the enlarging and debriding of root canals. The occurrence of undesired effects on the root canal walls was compared in vitro between a theoretically ideally shaped canal and the Canal Leader, Canal Finder, 3000 Endo Sonic Air, Cavi Endo 25, Enac System, Piezon Master 400 and the Canal Master. Clear casting resin models were used for this purpose. A photographic double exposure was used to superimpose the images of the original canals on the enlarged canals, thus enabling measurement of the material removed. Measurements were made at six different points. Significance was defined at the 5% level (P = 0.05). All instruments and/or devices, with the exception of the Cavi Endo 25, enlarged the convex side of the canals significantly greater at level 1 in comparison to the ideal. On the concave side, significantly smaller differences were found between the ideal and the results of all the enlarging devices, with the exception of the Canal Master. On the convex side at level 2, the Canal Leader, Canal Finder, Cavi Endo, Enac System and Endo Sonic Air showed no statistical differences between ideal and effective material removal. The Piezon Master showed significantly lower material removal in comparison to the ideal. The Canal Master demonstrated statistically higher differences when compared with the ideal.(ABSTRACT TRUNCATED AT 250 WORDS)
