SUCCESS FOR REMOVING OR BYPASSING INSTRUMENTS FRACTURED BEYOND THE ROOT CANAL CURVE – 45 CLINICAL CASES.

The aim of the study is to compare success rates for ultrasonic removal or bypassing endodontic instruments, fractured below the curve of root canals. Methods: 45 clinical cases – 30 MB and 5 ML root canals of mandibular molars, as well as 8 MB, 2 DB root canals of maxillary molars were selected from the authors’ private practice. 18 of the fragments are stainless steel files, 6 are rotary Ni-Ti files and 21 – lentulos. Fragments, to which visual access could be achieved by safe straightening of the root canal (26) were treated ultrasonically under dental microscope (OPMI Pico, Carl Zeiss) with magnification 10x and 16x. Bypass is chosen for fragments (19) without visibility. Results: Ultrasonic group: 22 of 26 fragments (84,61%) were totally removed, and full working length was consequently reached in 69,23 % of the cases (18 fragments). Four fragments (15,38%) separated additionally from the vibrations and could not be totally ultrasonically removed. Bypass group: only 7 of 19 fragments (36,84%) could be successfully bypassed. Conclusions: Ultrasonic technique for broken instruments removal is significantly more successful than bypassing. Straight visible access to the fragment under dental microscope is crucial for successful fragments retrieval. Key words: Broken, separated instruments retrieval, ultrasonic technique, bypass