If there is one condition that continues to humble clinicians at every level of experience, it is cracked tooth syndrome. Not because it is rare, not because we lack the knowledge to manage it, but because it is, by its very nature, one of the most difficult diagnoses in dentistry to make with confidence. And, right now, it seems clear that we are seeing more of it than ever.
Why now?
Dental practitioners have paid close attention to what has been happening to patients’ teeth since the pandemic. The data, when it began to emerge, confirmed what many of us were already observing. Several recent studies have found that over half of responding dentists reported increases in bruxism among their patients since the onset of COVID-19.[i][ii] A study examining endodontic practice records found that the rate of cracked teeth increased significantly during both the initial outbreak period and one year later.[iii] The researchers attributed this to pandemic-related anxiety, disrupted sleep, and a rise in parafunctional habits – in short, to a stressed population grinding and clenching under enormous collective pressure.
That pressure has not simply gone away. Chronic stress, sleep disruption, and the consequence of years of untreated parafunction do not resolve when the news cycle moves on. Bruxism can generate forces of up to 900N in some cases[iv] – more than sufficient to propagate cracks through otherwise healthy, unrestored tooth structure. We are now several years on from the initial pandemic period, and the downstream consequences are still arriving in our surgeries.
Understanding the crack
Understanding what constitutes a cracked tooth, and how a crack behaves, is essential. The Oral Health Foundation describes four crack categories, ranging from ‘craze lines’ – superficial enamel fractures of no immediate concern – through to cracked teeth, cracked cusp, and split tooth.[v] It’s the middle of this spectrum that causes the most difficulty. A cracked tooth may have an intact crown; it may cause no symptoms at all for months or even years. When symptoms do emerge, they are frequently inconsistent: pain on biting followed by relief on release, thermal sensitivity that the patient may struggle to localise.[vi] These are not textbook presentations and they do not show clearly on a periapical radiograph.
This is what makes managing cracked tooth syndrome genuinely challenging. The diagnosis rests heavily on clinical acumen – a methodical assessment and the right diagnostic tools applied in the right sequence. Transillumination can reveal crack lines invisible to the naked eye. Selective bite testing can reproduce symptoms and help isolate the affected tooth. Dye staining can identify crack progression. And, increasingly, CBCT is demonstrating its value in assessing the extent of cracks, particularly in complex or ambiguous cases.
Pulp fact
What matters enormously, however, is what is happening to the pulp. A crack that extends into the dentine allows bacteria to penetrate towards the pulp over time, resulting in potential pulpitis – initially reversible, but eventually irreversible – and, if left untreated, pulp necrosis and apical periodontitis.[vii] There is some evidence that bruxism, again, can lead to these endodontic issues even in otherwise intact teeth.[viii] The diagnosis in these cases is particularly elusive, because conventional aetiological factors, such as caries, restorations, and trauma, are absent. If pulpitis is not identified, the tooth can go untreated far longer than it should.
This is why I would urge every practitioner to actively screen for signs of bruxism and other parafunction – not just when a patient presents with acute symptoms. Enlarged masseter muscles, generalised tooth wear, tongue scalloping – these are signs of a patient placing their dentition under extraordinary force. It warrants a conversation, an assessment, and in some cases a protective appliance.
Mitigating a growing concern
For patients already presenting with pain, thermal sensitivity, and other symptoms consistent with cracked tooth syndrome, timely specialist referral can be the most protective response a clinician can offer. The prognosis for a cracked tooth is closely tied to the speed and accuracy of the diagnosis, extent of the progression of the crack, and the pulp status at the time of treatment. Once a crack has extended vertically into the root, the tooth is often unsalvageable. The window for intervention may close.
We may not be able to undo the stress our patients have been living with, but we can take seriously the damage it is doing to their teeth through quick and proactive response.
For further information about the endodontic referral services available from EndoCare, please call 020 7224 0999 or visit the NEW website www.endocare.co.uk
Author: Michael Sultan
[i] HPI poll: Dentists see increased prevalence of stress-related oral health conditions. adanews.ada.org. https://adanews.ada.org/ada-news/2021/march/hpi-poll-dentists-see-increased-prevalence-of-stress-related-oral-health-conditions/
[ii] Shalev-Antsel T, Winocur-Arias O, Friedman-Rubin P, et al. The continuous adverse impact of COVID-19 on temporomandibular disorders and bruxism: comparison of pre- during- and post-pandemic time periods. BMC Oral Health. 2023;23(1):716. Published 2023 Oct 4. doi:10.1186/s12903-023-03447-4
[iii] Nosrat A, Yu P, Verma P, Dianat O, Wu D, Fouad AF. Was the Coronavirus Disease 2019 Pandemic Associated with an Increased Rate of Cracked Teeth?. J Endod. 2022;48(10):1241-1247. doi:10.1016/j.joen.2022.07.002
[iv] Flanagan D. Bite force and dental implant treatment: a short review. Med Devices (Auckl). 2017;10:141-148. Published 2017 Jun 27. doi:10.2147/MDER.S130314
[v] Cracked teeth. Oral Health Foundation. https://www.dentalhealth.org/cracked-teeth
[vi] Mathew S, Thangavel B, Mathew CA, Kailasam S, Kumaravadivel K, Das A. Diagnosis of cracked tooth syndrome. J Pharm Bioallied Sci. 2012;4(Suppl 2):S242-S244. doi:10.4103/0975-7406.100219
[vii] American Association of Endodontists. Cracked Teeth | American Association of Endodontists. American Association of Endodontists. Published 2017. https://www.aae.org/patients/dental-symptoms/cracked-teeth/
[viii] Gund MP, Wrbas KT, Hannig M, Rupf S. Apical periodontitis after intense bruxism. BMC Oral Health. 2022;22(1):91. Published 2022 Mar 24. doi:10.1186/s12903-022-02123-3
