Fig. 1

High difficulty retreatment case:

This case was presented with failed primary treatment. Cliniucal and radiographic examination revealer unsuccessful primary treatment with a long separated instrument in the mesiobuccal root canal, short root fills in the ML and DB canals and missed anatomy (DL root canal)

The Crown was removed using sectioning and elevation. The intial intervention was directed to removal of the separated instrument from the MB canal, using Ultrasonics and grasping using a loop

https://youtu.be/OvKMxZLcozo

Given the difficulty of the anatomy, in this case, the full sequence of retreaty has been used. This is because there were mutliplanar curvatures, therefore it is needed to adress different parts of the root canal in a step down approach. The retreaty files were operated in ATR (Adaptive Torque Rotation) mode to be able to adapt to the complex anatomy using the ENDOMASTER console

 

Fig. 2

It is of great importance in failed treatments to follow a proper disinfection protocol for cleaning the complex root canal system utilizing efficient irrigant activation methods. In this case, activation of NaOCl and EDTA solution was performed using ULTRADANCER activator

Fig. 3

Moderate Difficulty retreatment case:

This mandibular left second molar was presented with failed primary treatment and symptomatic apical periodontitis. Clinical and radiographic examination revealed unsuccessful primary treatment with short root fills in all the three canals.

The Endo-Crown was removed by creating a groove at the margin followed by elevation. Gutta percha disassembly was facilitated by using medium powered ultrasonics without coolant to soften gutta percha, followed by mechanical removal using retreaty instruments.

In this case, Bull-Y (25/.07) removed most of the GP in the coronal half of the root canals, leaving very wide coronal portion, so that Skinny (25/.04) and Shapy-1 (20/.05) were unneeded. Therefore, the remaining parts of Guttapercha was removed using Shapy-2 (25/.05) and Shapy-3 (30/.05)

Remnants of gutta perchga were detached using the ULTRADANCER activator and caught using a Hedström file

Fig. 4

Simple retreatment case:

This maxillary left second premolar was presented with failed primary treatment and symptomatic apical periodontitis. Clinical and radiographic examination revealed unsuccessful primary treatment with short root fills in both canals. The only factior that was complicating regaining access to the root canal system was the presence of a metallic retention element (screw post)

The screw post was removed using medium powered ultrasonic tip with intermittent cooling, operated in a counterclockwise motion around the post. Gutta percha disassembly was facilitated by using medium powered ultrasonics without coolant to soften gutta percha, followed by mechanical removal using retreaty files.

In this case, Bull-Y (25/.07) removed most of the GP in the coronal half of the root canals, leaving very wide coronal portion, so that Skinny (25/.04) and Shapy-1 (20/.05) and Shapy-2 (25/.05) were unneeded. Therefore, the remaining parts of Guttapercha was removed only using Shapy-3 (30/.05), after extasblishing patency and working length determinatrion

Conclusions

Conclusions:

Success in Non-Surgical Retreatments depends on a triad of, Strategic Planning, Proper Armamentaria (tools) as well as Experienced clinician.

The Retreaty Instrument kit is considered a dynamic kit since it contains instruments with different metallurgies (heat treatments) adaptable to different anatomies, as well as a sequence which can be customized by the clinician to adapt to different cases with variable difficulties 

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