This patient attended in pain from the UL5 and a diagnosis was made of symptomatic Apical Periodontitis. I was aware that the presence of an apical radiolucency, curved roots and a heavily restored crown meant that the tooth had a guarded prognosis, but as the patient was keen to keep the tooth we began root canal treatment. I placed rubber dam, accessed the tooth, located the canals, patency filed and irrigated.
At university I had trained by using the step-back technique with K files, and Pro-Taper hand files. I had starting using rotary instruments in my DF1 placement and I attempted to use the rotary files to my corrected working length, but struggled to do so due to the canal curvature. I had struggled to get to grips with using rotary instruments in more curved canals and I therefore returned to using the step-back technique and K-files.
Upon obturation, I noted that something was awry as the Thermafil would not seat to length. I was aware that the gutta percha (GP) was unable to negotiate the canal curvature and a radiograph showed that the GP was not at length, and some had entered the 2nd canal.
In order to achieve a satisfactory result, I needed to remove GP using DMZ-IV and Pro-Taper re-treatment files. This was my first experience of removing GP and I was careful to ensure complete removal of the GP, before re-preparing the canals chemo-mechanically. As I had evidently failed to sufficiently prepare the canals for GP the first time round, I spent some time enlarging the orifice using hand files and using EDTA to ensure that I could use the Pro-Taper files to length prior to obturation. I then obturated using Thermafil, and have subsequently restored the tooth using a porcelain onlay.
An S-shaped curvature or double curvature can make a canal very challenging to negotiate. I learned that using hand files initially can help prepare the canal sufficiently prior to using rotary files. I now know to approach curved canals like these with more caution, and to take time preparing the canals ensuring adequate mechanical preparation. I had never used re-treatment files before and I learnt to use a pecking motion and ensure visualisation of GP on the files. I now feel more confident in doing this and therefore more able to attempt re-root treatment in the future.
I chose a porcelain onlay to restore the tooth as it provided excellent aesthetics, cuspal coverage and also helped to preserve more of the buccal and lingual tooth present, which would have been destroyed had I chosen to perform a crown preparation. The tooth was in the patient’s smile line and she was very pleased with the aesthetic result. Overall, I was pleased with the end result of this root canal treatment and hope that the patient is able to retain this tooth for many years as a result.
I feel that this case helped me to develop my endodontic skills overall as it involved improving upon a myriad of skills. Firstly, my assessment of a case; I had not previously spent a long time analysing the curvature of the roots and the effect this would have on my method of root filling the tooth. Since this case I have become acutely aware of the need to tailor your technique to the type of roots present, including ensuring adequate access, the need for anticurvature filing, and the advantages and disadvantages of using rotary instrumentation in these cases. Secondly, it made me realise the importance of establishing the aetiology of any problems encountered. I realised that as my GP had not seated to length that I had evidently not prepared the canals adequately and by establishing this aetiology I could therefore improve the outcome by rectifying this problem. I have also realised that acknowledging your own limitations and competency is key in endodontics; I was aware that the initial treatment I provided was poor, but that rectifying it may be difficult. I therefore ensured I informed the patient that I would try my best to improve on the root treatment, but that should it be beyond my competency we would have to consider alternative pathways.
This case helped me improve upon my endodontic planning and also, the techniques involved in S- shaped root canals. It has encouraged me to realise that if an ideal result is not achieved initially, things can be improved upon and should not just be accepted. DT
Fig 1 - Pre- operative Radiograph taken 15/04/2013
Fig 2 - Working length Radiograph taken 29/04/2013
Fig 3 - Mid-obturation Radiograph taken 20/05/2013
Fig 4 - Post-op Radiograph taken 20/05/2013
Textbook of Endodontology, Gunnar Bergenholtz, Preben Horsted-Bindslev, Claes Reit Second Edition
Harty’s Endondontics in Clinical Practice, Bun San Chong, Sixth Edition
About the Author
At the time of this case, Lydia was working in a Bristol dental practice as a foundation dentist, in her second year of vocational training.