COLTENE’s Mark Allen: Endodontics and getting to the root of longitudinal fractures
Longitudinal fractures can be problematic, because they tend to grow and change over time and can on occasion require a predictive diagnosis rather than definitive identification. This, in turn, can lead to incorrect diagnosis and delivery of inappropriate treatment, compromising the long-term survival of the patient’s affected tooth.
If a practitioner is able to successfully identify and classify the crack type at an early enough stage, however, there is a chance that a tooth with a vertical crack or fracture can be saved – though the outcome, as always, will depend on the diagnosis.
Subject to the location and extent of the crack, it may be that the tooth is unable to be saved, resulting in extraction.
Longitudinal fractures can be divided into five classifications: craze lines, fractured cusp, cracked tooth, split tooth and vertical tooth fracture . There are a number of reasons why these longitudinal fractures develop, including predisposing factors that place patients at higher risk. Age is one such factor, with a number of studies indicating that the prevalence of cracks is more common in patients aged above 40 .
A number of reports also indicate a possible link between restorations and cracks. As it is possible that teeth restored with amalgam and inlays could be more prone to cracks , it might be suggested that patients who have undergone restorative treatments should be monitored more closely post-treatment. But it's not just restorative dentistry that poses a risk.
It is thought that endodontic treatment can increase the risk of vertical root fractures. Excessive removal of dentine during coronal enlargement of the canal and post space preparation is one risk factor , with root canal obturation and post placement also thought to lead to root fractures – especially in the apical region .
Other possible causes of endodontic-related fractures can include: excess force during the use of lateral condensation technique; wedging effect during lateral condensation and as a result of tapered end posts; and stresses from cementation of posts [4 & 5}.iv,v
To minimise the risk of vertical root fractures occurring, both general dental practitioners and specialist endodontists are advised to take extra precautions during endodontic treatment. That includes going the extra mile to use quality equipment from a reputable manufacturer.
For example, the HyFlex EDM NiTi files from COLTENE with controlled memory effect have been designed to offer ultimate flexibility so that the root canal anatomy isn’t compromised during cleaning and shaping. The same goes for any endodontic treatment carried out to treat a longitudinal fracture (in some instances root canal therapy is a suitable pathway), because one wrong move could result in further fractures later on down the line.
With a sound knowledge of the five classifications, risk factors and preventive measures, practitioners are able to minimise prevalence of longitudinal fractures and improve tooth vitality for patients.
1] American Association of Endodontists. Cracking the cracked tooth code: detection and treatment of various longitudinal tooth fractures. In: Endodontics: colleagues for excellence. 2008. Accessed online April 2018 at https://www.aae.org/specialty/wp-content/uploads/sites/2/2017/07/ecfesum08.pdf
2] Roh BD, Lee YE. Analysis of 154 cases of teeth with cracks. Dent Traumatol. 2006; 22 (3): 118-123. Accessed online April 2018 at https://onlinelibrary.wiley.com/doi/full/10.1111/j.1600-9657.2006.00347.x
3] Seo DG, Yi YA, Shin SJ, Park JW. Analysis of factors associated with cracked teeth. J Endod. 2012; 38 (3): 288-292. Accessed online April 2018 at https://www.ncbi.nlm.nih.gov/pubmed/22341061
4] Khasnis SA, Kidiyoor KH, Patil AB, Kenganal SB. Vertical root fractures and their management. J Conserv Dent. 2014; 17 (2): 103-110. Accessed online April 2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4001262/
5] Malhotra N, Mala K, Acharaya, SR. A review of root fractures: Diagnosis, treatment and prognosis. Dental Update. 2011; 38 (9): 615-628. Accessed online April 2018 click HERE.