Effects of seven different irrigation techniques on debris and the smear layer: a scanning electron microscopy study

Conventional manual irrigation with a syringe and needle remains widely accepted technique in the irrigation procedures. However, its flushing action has some limitations. Currently, several techniques and systems are available and reported to improve the insufficiency of syringe irrigation. The aim of this study was to evaluate the effectiveness of 7 different irrigation techniques compared to standard irrigation.

Straight roots from 80 extracted human maxillary central incisors were collected, and root canals were instrumented with K-files up to apical size 50. The teeth were randomly divided into 8 groups (n = 10), and final irrigation procedures were performed with 17% ethylenediaminetetraacetic acid and 5.25% NaOCl solutions using following irrigation agitation techniques: RinsEndo, EndoVac, Canal CleanMax, sonic, Canal Brush, NaviTip FX, manual dynamic irrigation, and conventional irrigation. The presence of debris and smear layer (SL) at coronal, middle, and apical thirds was evaluated by using a 5-grade scoring system with ×200 and ×1000 magnification, respectively.

Concerning debris removal, the MM 1500 sonic group reduced apical debris significantly better than the other groups tested (P < 0.05). There was no significant difference among the tested groups (P > 0.05) related SL removal in all levels.

MM 1500 scored best with debris removal; however, there was no significant reduction in the SL in apical third with any of the methods tested.