The K15-21 tips from ACTEON, sold in packs of 4, are steel K-type files, ISO size 15 (white color-coding), 21 mm in length, mounted on a body adaptable to the ultrasonic generator. This gauge, slightly larger than ISO 10, suits canals of a somewhat wider diameter while retaining the fine precision needed for accurate work.
They are used to activate irrigation at the start of treatment, promoting decontamination of the canal walls, as well as for orthograde retreatment and cleaning narrow areas during retrograde treatments, without risk of creating parietal microfissures. Used with an ACTEON-compatible ultrasonic generator.