Fig. 1

A 51-year-old female patient was suffering from persistent severe pain from lower right first molar (#46 when shaving any cold fluids, the pain increases severely and may last for a long period of up to an hour. She had these symptoms for many months before the pain intensified and made her wake up from sleep, and she was taking a lot of painkillers, which caused her also gastritis (5) . As for consuming warm drinks, the pain is present, but it does not last for a long time, as it happens from its cold counterpart.

Suddenly the analgesics did not have any effect, but the intake of cold liquids also made the pain disappear completely for a period of several minutes. This prompted her to go to the dentist on the same day.

During clinical examination, it was found that the patient had not any carious lesion at occlusal surface of tooth #46, but by examination of inter-proximal surfaces a large deep distal cavity was found which was confirmed by  x-ray . Patient had also pain with percussion.

All of this are typical signs and symptoms of irreversible pulpitis (6) which require pulpectomy and root canal filling, because inflamed vital pulp is not capable of healing. (7)

Fig. 2

The treatment of this molar was completed in one session, since in the beginning most of the caries was removed but without complete deroofing of pulp chamber to avoid contamination.(8) And then a complete isolation was done using Rubber dam in-addition to use a liquid dam which is very helpful in sealing off any areas that may have any seepage.(8,9) Complete the pulp chamber opening to make a traditional access opening then the access was refined by using ultrasonic tips leading to the discovery of the four  root canals orifices. By using the Apex Locator Working length was measured then it was confirmed using x-rays.

During the Chemo-mechanical preparation of the canals, it was noticed that the Canals were wider in the coronal two thirds in comparison with apical third specially in the distal root, in addition the canal orifices of the distal root was close to each other which puts a high probability that these canals have two orifices and one apex (Type II )(10), and this is what was discovered to be true during preparation

On the Master Cone x-ray، everything seemed fine, so the tooth was obturated using single cone with calcium silicate-based bioceramic sealer and modified vertical compaction.

Fig. 3

It was a big shock when examining the post-operative x-rays, as it is clear in the x-rays, the red arrow indicates the presence of a thin canal that was filled by the bioceramic sealer only, Which means that it was cleaned only chemically thanks to the penetration of the irrigating materials  and not mechanically by files. which raised a lot of questions:

  • Were the two distal canals completely separate (type IV)(10) and did not have the same apex as was believed during the preparation procedure?
  • May be was it an accessory canal that was chemically cleaned well .

Many possibilities which need further examination in order to clarify the problem “ if exist” . As each scenario has a different way to deal with it. So for better tooth evaluation,CBCT is requested (34).

Fig. 4

By means of the CBCT, the entire molar was examined to ensure the quality of preparation for the canals as well as the obturation.

  1. Coronal view for mesial root shows only two canals which seems to be good prepared and obturated up to the apex.
  2. Axial view : MBa canal is obturated with its isthmus, the two distal canals are so close to appear one large canal.
  3. Coronal view for Distal root approve that the canal anatomy Type II (two canals with one apex) in addition to small lingual accessory canal ( red arrow ) .

According to the CBCT analysis result : That canal was an accessory canal that thanks to good irrigation protocol, it was cleaned and duo to the good follow of bioceramic sealer, it was good  obturated (33) .

Fig. 5

In this case the effect of the good irrigation is undeniable. As shown, this was the irrigation protocol that relied on a group of irrigating materials in an orderly sequence to ensure good chemical cleaning of the root canal system, as each of this materials have a specific function.

Sodium hypochlorite 5,25% ( NaOCl ): the main irrigating solution used to dissolve organic matter and kill microbes effectively (12-15)

Ethylenediaminetetraacetic acid (EDTA): is needed as a final rinse to remove the smear layer.(12-15) But it has been used in this protocol more than once to ensure that the dentinal tubules are open to grantee that NaOCl well reach every point of root canal system.

saline: used between these two irrigants to avoid the chemical interaction between them(12,14)

It was necessary to guarantee the safety and not to pass any of these materials beyond the root apex, also a Gauge 30, double side vented irrigating needle was used to deliver the irrigating material to each canal in depth shorter than the working length by 3 mm.(16)        

The activation of irrigant was done by using an ultrasonic activator, the duration of each activation last for 20 sec.(11)

Fig. 6

The author: Dr. Mohamed M. Elhalawany

Date of birth: 10 june 1985 , in Wroclaw، Poland
Graduation from Dental Collage, Alexandria university, Egypt - in 2007
Owner and founder of Halawany Dental Center since November 2009 
Since 2017 works exclusively in endodontics and micro-endodontics surgery 
From 2008 - now: working as a dentist in Egyptian ministry of health hospitals 
From 2015 to 2018: Head of the Dental Department at Al-Imam Al-Bukhari Hospital - Borg Al Arab - Alexandria
From 2018 to 2020: director of the same hospital
2009 - 2013 Member at the International congress of Implantology (ICOI),USA
2007-2013 Member at the Alexandria oral implantology association (AOIA),Egypt


Irrigation is a key part of successful root canal treatment. It has several important functions, which may vary according to the irrigant used: it reduces friction between the instrument and dentine, improves the cutting effectiveness of the files, dissolves tissue, cools the file and tooth, and furthermore, it has a washing effect and an antimicrobial/antibiofilm effect. Irrigation is also the only way to impact those areas of the root canal wall not touched by mechanical instrumentation.(17)

Much of the research on endodontic irrigation has focused on the effect of irrigation on the smear layer.(17-21) However, smear layer removal can be accomplished relatively easily when correct protocols are followed. A bigger challenge for irrigation may be the areas untouched by the files, such as fins, isthmuses and large lateral canals.(22) Also, large areas in the oval and flat canals may remain untouched despite careful instrumentation. These areas contain tissue remnants and biofilms that only can be removed by chemical means using irrigation. The apical root canal poses a special challenge to irrigation as the balance between safety and effectiveness is particularly important in this area. (23) Small, 30-gauge side-vented needles and/or negative pressure irrigation in the apical canal will secure the best results in this important area.

Ultrasonic irrigation using ultrasonic tips to deliver the solutions directly into the canal space have shown promising results for cleaning even the most difficult areas such as long and narrow isthmuses between two canals.( 24-26)

Sodium hypochlorite (NaOCl) is the most important irrigant in root canal treatment.(27-29) It is the only presently used solution that can dissolve organic matter in the canal. Therefore the use of hypochlorite is of utmost importance in removing necrotic tissue remnants as well as biofilm. (30-32)


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