Dealing with hard canals, the easy way. 

Fig. 1

Upper second premolar (#15) 

The patient was referred and presented with thermal hyperesthesia and reported discomfort upon masticatory exertion.

Radiographic evaluation of the maxillary left second premolar revealed distal carious involvement. The internal morphology suggested anatomical intricacies, with a provisional diagnosis indicating a potential supernumerary root.

Fig. 2

Multiple isolation was placed with clasps on the teeth #24 and #26.

The old restoration and the carious lesion were removed.

Under high microscopic magnification, a split of the mesial buccal root is observed with two orifices. 

A coronal flaring of the canals was performed using a 25/0.4 rotary instrument at 500rpm. 

Fig. 3

The coronal flaring of the canals in such cases is vital, as it will remove coronal pulp tissue and create space for the NaOCl solution to dissolve tissue and enhance the lubricating effect of our first files attempting to reach the apical constriction of the root canal. A 5.25% solution of NaOCl delivered through an irriflex needle is . 

Once we have rinsed the canals with a fair amount of NaOCl solution, the #8 K hand file reaches the working length of the canal even at the double curved DB root. 

The working length estimation was carried out with the us of an electronic apex locator (Morita ZX mini). 

The next step would be to create a reproducible glide path using a 15/0.3 NiTi rotary instrument with high flexibility. In this case, Plex V (Orodeca) was used. 

At 300 rpm and torque 0.6 we performed gentle pecking motions in the canal, 2-3 mm each time, before cleaning the instrument and repeating the process to full working length. The files are put to motion after their placement in the canal. Every 5 seconds of rotary instrumentation the canal is washed with NaOCl 5.25% delivered by an irriflex needle until no more debris can be seen exiting the canal and the files are inspected.

Its important to note that in this step, the tactile sense is crucial as we must feel the resistance of the motion and avoid debris accumulation. 

Creating a glide path, is the checkpoint of our shaping procedure as it will make the following process predictable. The final apical sizes of preparation were 25/0.4 for the buccal canals and 40/0.4 for the palatal.

Fig. 4

Finally, the shaping procedure was completed, and the gutta-percha cones were fitted in the canals. Sterilized scissors were used to adjust the cones and ensure an apical seal before the final irrigation protocol was carried out. 

It is always important to mention that shaping is responsible for creating sufficient space in the canal systems. By doing that the irrigating solutions can disinfect its three-dimensional structure, especially in complex anatomies like the one being shown. 

-Final irrigation protocol: 

Needle used: Irriflex

In order: 

1. 1.NaOCl 5.25% solution is injected in the canals and activated for 30 seconds each with sonic activation (Eddy VDW)
2. 2.EDTA 17% solution is injected and activated for 30 seconds at each canal (3 times) with sonic activation.
3. 3.NaOCl 5.25% solution is injected in the canals and heated with a plugger at 180 degrees for 3 seconds in each canal (3 times)
4. 4.A final, sonic activation of each canal was performed for 30 seconds
5. 5.All canals were washed with saline and dried with sterile paper points.

Fig. 5

The obturation of each canal was performed with a single cone-warm vertical compaction technique and bioceramic sealer (Ceraseal). The patient was referred back for restorative and prosthetic rehabilitation of the tooth. 

Fig. 6

The story of a unique upper second molar, presenting a long palatal root canal with a working length of 32mm and a severe apical curvature by the mesial root canal. 

The workflow followed on this case didn’t differ from the previously mentioned case, with just one important detail. The mesial root canal was very thin and the apical hook too sharp for a hand instrument to scout. 

Fig. 7

In this case the scouting and the working length determination was carried out with a 15/0.3 NiTi instrument, following the same guidelines with the three rooted premolar and the assistance of lubricant (RC prep). The endo motor was connected with an electronic apex locator. After several gentle peckings and multiple rinsing of the canals with NaOCl 5.25% delivered through an irriflex irrigation needle, the glide path file was able to overcome the sharp turn with ease and provided the space required for our 20/0.4 NiTi file to finish the shaping of the root canal in this case.  

Fig. 8

Single Cone Warm obturation for all three canals combined with bioceramic sealer (Ceraseal). 

A temporary restorative material was placed on top of a sterilized cotton pellet and the patient was referred back for indirect restoration.