A COMPARISON OF MAINTENANCE OF CANAL CURVATURE USING BALANCED-FORCE INSTRUMENTATION WITH 3 DIFFERENT FILE TYPES

Forty-five extracted human molar teeth with curved facial or mesial ca nals were instrumented to a #45 file with three different file types u sing balanced-force (BF) instrumentation. Pre- and postoperative X-ray s were taken, projected, and file location traced to determine the can al curvature according to the method of Schneider. Results showed stat istically less reduction in canal curvature with nickel-titanium (NT) files compared with either Flex-R (FR) (p < 0.05) or K-Flex (KF) files (p < 0.0021). There was no significant difference comparing FR with K F files (p > 0.05), Under the conditions of this study, NT files used with the BF technique were significantly less likely to change canal c urvature than either FR or KF files when instrumenting curved root can als.