The impact of the pecking motion on the success of endodontic treatment
Featured Products Promotional FeaturesPosted by: Dental Design 7th May 2023
When carrying out endodontic treatment, it is important to do all you can to minimise the risk of file fracture. The pecking motion is commonly used as part of root canal treatment to gain length, but it comes with its risks. A frequent pecking motion decreases the file’s resistance to cyclic fatigue, causing the endodontic rotary instrument to fracture.[i] This is because the file is being allowed to rotate freely while also being subjected to repeated tension and compression, eventually causing the file to break.[ii]
Because of this, it is recommended that clinicians adopt a low frequency of pecking motion in order to reduce the risk of cyclical fatigue, and therefore reduce the risk of failure in endodontic files and endodontic treatment.i
Choice of file
The likelihood of fracturing endodontic instruments ranges from 0.7% to 6%. This is a complication which is usually avoidable, when you know what signs to look out for.[iii] The choice of file can have a big impact on the likelihood of file failure. With instruments made of stainless-steel showing signs of metal fatigue, making it easy to know when to discard the instrument. When using instruments made of NiTi, however, it can be harder to tell. Fracture may happen without showing any obvious signs of strain. Generally, NiTi instruments are less likely to break – reducing the chances to around 0.9% – but it is not impossible, under certain circumstances.iii
Reasons for file fracture largely come down to fatigue, either due to over-bending or over-twisting. It is important that endodontists understand what must be done should they have to deal with file fracture. In most cases, retrieving the fractured instrument is the right course of action, widening the root canal to access and extract the fractured instrument. Generally, there are high success rates for removing fragments, but as it involves additional canal widening, it is not an ideal outcome. In some cases, however, the broken file may not cause any inflammation, and it may be appropriate to ensure proper sterilisation, and not extract the broken piece. This means that no unnecessary healthy tissue is removed, and the treated tooth can remain healthy.iii
This is particularly true in the middle and apical part of the canal, where it may be more dangerous to remove healthy tissue and retrieve the broken instrument, than to leave it there. If the instrument is fractured in the coronal part, however, extraction of the fractured file should be attempted, while ensuring that only minimal tissue is removed. When making these decisions, it is important to consider the effect that either option will have on the success of the treatment, and your patient’s health.iii
Choice of technique
It is important to reduce the stresses put on an endodontic rotary file as much as possible, in order to reduce the risk of fracture. As mentioned, using a pecking motion is likely to increase the pressures put on your endodontic instrument. Therefore, this action should be avoided and files should be changed regularly to minimise the risk of breakage.
It can be challenging to know when is best to change files. Recent developments in dental technology have helped to improve this, monitoring the stresses on endodontic instruments, taking the guess work out of root canal treatment. This means that you are far less likely to change your endodontic file too late or too soon, therefore minimising the risk of breakage and maximising the life of your endodontic file. Utilising this technology will allow you to operate more efficiently, and more accurately, ensuring your patients receive predictable care, and that you can achieve outstanding results. Plus, this new technology will actually help you to save time, and money, by not removing files too quickly, and replacing them with new ones.
The CanalPro™ Jeni endomotor from COLTENE is the autonomous assistance system which helps clinicians achieve safer, more efficient, and simpler endodontic treatment. The Jeni assistant controls file movements with precision, constantly regulating the rotary movements and speed, as well as monitoring factors like intensity, torque, and file stress. This means that the system is able to constantly adapt to the unique contours of the individual root canal anatomy, allowing you to move steadily through the canal, avoiding the need for a pecking motion. And the CanalPro™ Jeni will alert you when it’s a good time to irrigate or change the file, so you will not have to second guess when it’s time to change, helping to minimise the risk of file fatigue and fracture.
Carrying out high quality endodontic treatment is vital, helping you to build trust with your patients, produce excellent results, and help to ensure patients are free of the pain caused by pulpitis. By tackling the common challenges presented by endodontic treatment, and using equipment and techniques which allow you to reduce the risk of file breakage, you are far more likely to produce successful endodontic outcomes.
For more on COLTENE, visit www.coltene.com,
email info.uk@coltene.com or call 0800 254 5115.
Author: Mark Allen, General Manager at COLTENE
[i] Zubizarreta-Macho, Álvaro, et al. “Influence of the pecking motion frequency on the cyclic fatigue resistance of endodontic rotary files.” Journal of clinical medicine 9.1 (2019): 45. https://www.mdpi.com/2077-0383/9/1/45/htm
[ii] Ferreira, F., et al. “Movement kinematics and cyclic fatigue of NiTi rotary instruments: a systematic review.” International endodontic journal 50.2 (2017): 143-152. https://onlinelibrary.wiley.com/doi/full/10.1111/iej.12613
[iii] https://www.aae.org/specialty/communique/broken-instruments-clinical-decision-making-algorithm/
