Investigation of structural changes of Xp- Endo finisher rotary files after frequent use

Abstract

Introduction: In this study, the structural changes caused by frequent use of Xp-Endo finisher files were investigated. Mtherials and methods: For this purpose, 32 files of XP-Endo were selected and examined by an optical microscope to investigate the damage caused by the factory and then were used in the single canal maxillary anterior teeth with a CRO less than 5 degrees and without calcification. File defects checking was conducted by an optical microscope with 20X magnification in one, two and three times use and was evaluated by two observers with naked eye to observe file changes, in which the coefficient of agreement between two observers (Kappa) was 0.98. Results: The studies showed that with one time use of Xp-Endo finisher files, 11 samples (34.37%), with two times use, 8 samples (25%), and with three time use , 6 samples (18.75%) showed no structural changes. Also, the study of the structural changes in the Xp-Endo finisher rotary files by frequent usages showed that 25% of one time used samples had bended instruments, 15.42% had flattening of file flutes and 62.5% had deflection in the cutting edges. For two times usage, 31.25% of samples had bended instruments, 21.87% had flattening of file flutes and 65.62% had deflection in the cutting edges. For three times usage, 43.75% of samples had bended instruments, 18.75% had flattening of file flutes and 75% had deflection in the cutting edges.