Combination of apex locator and endodontic motor for continuous length control during root canal treatment

To compare ex vivo an experimental setup consisting of an electronic apex locator (EAL) and endodontic motor with an established product (Tri Auto ZX) for accuracy of length control during root canal treatment with three different types of files. An experimental setup consisting of porous spongy material and an electrolyte was used. Sixty anterior teeth were randomly assigned to six groups. Access cavities were prepared. During root canal treatment, constant length monitoring was performed either with the Tri Auto ZX or the Raypex (R) 5 apex locator attached to an endodontic motor (Endo IT professional) using ProTaper, M(two) or FlexMaster files. After root canal preparation the distances between file tip and major apical foramen and file tip and minor apical foramen were measured using a microscope and analysed using two-way anova to evaluate the accuracy of the two systems. Distances between the file tip and the major apical foramen were not significantly different between the file systems and the two EALs. In cases treated with FlexMaster significantly larger distances between file tip and minor apical foramen were found compared to M(two) and ProTaper. No significant differences were observed between the two EALs. After preparation of the root canals with the Tri Auto ZX, multiple minor apical foramina were mechanically widened. With the limitation of this laboratory study the combination of EAL and endodontic motor was as accurate as the Tri Auto ZX system in terms of length control during root canal preparation.