Microscopic evaluation of three endodontic files pre- and postinstrumentation.
K-type files, Sureflex NiTi files, and FlexoFiles were evaluated morphometrically as they come from the manufacturer, and after being used to instrument root canals 1, 3, and 5 times in maxillary premolars. Evaluation was made using a stereomicroscope at x40 magnification and photomicrographs. The abnormalities found after instrumentation were submitted for statistical analysis. It was concluded that small-sized stainless-steel instruments should be discarded after one use. On the other hand, #30 stainless-steel K-files could be used up to three times and #30 stainless-steel FlexoFiles up to five times. Sureflex NiTi instruments, even after five times, did not show appreciable abnormalities in shape. It is strongly recommended that small-sized nickel-titanium instruments should be discarded after five uses.
Computing Resources Department, University of Texas Health Science Center at San Antonio 78284-7892, USA.
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Bonetti Filho
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Miranda Esberard
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de Toledo Leonardo
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del Rio
D000497:Alloys; D000704:Analysis of Variance; D003762:Dental Instruments; D004868:Equipment Failure; D005069:Evaluation Studies as Topic; D006801:Humans; D018915:Root Canal Preparation / Q000295:instrumentation*; D013193:Stainless Steel
D000497:Alloys; D013193:Stainless Steel; C013616:nitinol