A comparative study of the cleaning effect of various ultrasonic cleaners on new, unused endodontic instruments

Background and aim: this study was carried out to compare three different ultrasonic cleaner devices in the cleaningprocess of endodontic instruments by scanning electron microscope (sem).methods: in this study, 120 unused brand new hand and rotary instruments were examined after removing from thesealed package. the instruments were randomly divided into six groups of 20 rotary or hand files each and observed bysem before ultra-sonication. then, every pair of hand and rotary instruments was cleaned using one of the ultrasoniccleaner brands. again the instruments were examined by sem and assessed in three different parts, tip, middle anddistance 16 (d16). sem data were analyzed by kurskal–wallis and mann–whitney tests.results: the tip of the endodontic instruments was the most contaminated area before ultrasonic cleaning. statisticalanalysis showed that all of the tested ultrasonic devices were significantly effective machines for debris removal fromendodontic instruments. the hand and rotary instruments cleaned by one of the devices were significantly cleaner thanthe others (p < 0.050). there was a significant difference in cleaning of the separate parts of the instruments duringultra-sonication among ultrasonic cleaners. the tips of the instruments were significantly cleaner than the d16 parts(p < 0.050).conclusion: various ultrasonic devices have different ability for cleaning of endodontic instruments.