A comparison of Profile, Hero 642, and K3 instrumentation systems in teeth using digital imaging analysis.

OBJECTIVE To evaluate the changes in cross-sectional area morphology of curved canals after instrumentation with Profile((R)), Hero 642((R)), and K3((R)) using digital imaging analysis. Study design Thirty mesial mandibular curved canals were used (25-40 degrees ). The molars were embedded in resin and the roots were sectioned transversely at three levels: apical, middle, and coronal. The canals were randomly distributed into 3 groups for instrumentation using Profile.04 and.06, Hero 642, and K3. The pre- and postinstrumentation sections were digitized and areas corresponding to the canals were measured with image-processing software. RESULTS Hero eliminated significantly more dentine than K3 and Profile in all 3 sections (P <.01, ANOVA test), with no differences observed between the latter 2 systems (P >.05, Student-Newman-Keuls test). All 3 systems yielded a rounded canal morphology in the coronal, middle, and apical thirds. CONCLUSION Hero rotary instruments produced more changes in cross-sectional area of the root canal.