In the next molar, MB1 and MB2 are independent, but they have a communicating canal between them, through which the flow of irrigants is created with negative pressure

It can also be useful in mesial roots of lower molars, since many times both canals are connected by isthmuses.

Fig. 1

X-rays and CBCT of the previous case.

In cases with drainage of the periapical tissues, the use of an aspiration cannula helps us facilitate the drainage of the contents of the lesion.

Lower incisor with suppuration after initial access.

Upper incisor with suppuration after accessing the interior of the canal.

In the following video, of an upper molar, where MB1 and MB2 join to separate again apically, you can see how we use the microcannula to aspirate while irrigating through the other confluent canal, creating a flow of irrigants between canals.

Lower molar after filling and negative pressure irrigation of the medial root.

In this video, you can see how, with the microcannula, we aspirate a piece of file that had previously entered the palatal canal when trying to remove it.

In the following video, we can see how we dry the canal from the apical side with the microcannula during a surgical endodontic retreatment.

In an incisor with an immature apex, we can aspirate with the microcannula from the apical area (irrigation by negative apical pressure), allowing the irrigants to be brought to the apical area without risk of extrusion.

Fig. 2

About the author:

Alberto Morales Cuellar

Degree in dentistry at the Complutense University of Madrid, 2013

Master in Advanced Endodontics at Rey Juan Carlos University, 2017

Master Periodontics and soft tissue management at CEU Cardenal Herrera, 2020

Professor of Master of Microscopic Endodontics and Apical Surgery (URJC)

Opinion leader of Zarc4Endo

Style Italiano Endodontics Fellow member

Full member of the Spanish Association of Endodontics.

Member of the American Association of Endodontists.

Winner of the Best Training Presentation of the College of Dentists of Madrid


The use of a small cannula, which allows us to insert it into the canal, and which is connected to the suction of the equipment, can be very useful during different steps of the endodontic treatment.

Facilitating different processes, such as irrigation with negative pressure and speeding up other processes, such as drying the canals during the irrigation phase.


Widjiastuti I, Rudyanto D, Yuanita T, Bramantoro T, Aries Widodo W. Cleaning Efficacy of Root Canal Irrigation with Positive and Negative Pressure System. Iran Endod J. 2018 Summer;13(3):398-402. doi: 10.22037/iej.v13i3.20875. PMID: 30083214; PMCID: PMC6064011.

Jamleh A, Fukumoto Y, Takatomo Y, Kobayashi C, Suda H, Adorno CG. A comparison between two negative pressure irrigation techniques in simulated immature tooth: an ex vivo study. Clin Oral Investig. 2016 Jan;20(1):125-31. doi: 10.1007/s00784-015-1489-1. Epub 2015 May 13. PMID: 25963721.

Fukumoto Y, Kikuchi I, Yoshioka T, Kobayashi C, Suda H. An ex vivo evaluation of a new root canal irrigation technique with intracanal aspiration. Int Endod J. 2006 Feb;39(2):93-9. doi: 10.1111/j.1365-2591.2006.01050.x. PMID: 16454788.

Haapasalo M, Shen Y, Wang Z, Gao Y. Irrigation in endodontics. Br Dent J. 2014 Mar;216(6):299-303. doi: 10.1038/sj.bdj.2014.204. PMID: 24651335.

Regan JD, Fleury AA. Irrigants in non-surgical endodontic treatment. J Ir Dent Assoc. 2006 Autumn;52(2):84-92. PMID: 16989370.