A Dark or Dead Tooth: Causes and Options
This page explains why one tooth turns dark or grey from the inside, the link with injury and a dead (non-vital) pulp, that infection can cause no symptoms, how vitality is tested, and the general order of care, with the pulp and any infection first, then the colour. Show any darkening tooth to a dentist.
5.0 from 550+ Google reviews
Open 8am to 8pm, seven days
Free parking at the door
CQC & GDC registered
No referral needed
Clinically reviewed by Dr Ibraheem Ijaz, dentist · GDC 301711
Medical disclaimer: This page is for general information only. It does not replace an examination or treatment by a dentist.
Dr Ibraheem Ijaz, principal dentist at Deepcar Dental Care, reviewed this page. He is a General Dental Practitioner, GDC 301711, with BDS, BSc (Hons) and MSc (Leeds).
Why does a tooth turn dark from the inside?
A tooth can darken from the inside because of changes in the pulp, the soft tissue that holds its nerve and blood supply.
A 2022 International Endodontic Journal review says bleeding inside the pulp after an injury (intrapulpal haemorrhage) often discolours a tooth, and iron from the broken-down blood often turns it brown, reddish or black, especially where the pulp dies (pulp necrosis), leaving a non-vital, or dead, tooth. The review also lists calcification of the root canal after injury, and pulp or filling material left after root canal treatment, as causes. Other causes of intrinsic and extrinsic staining are covered separately.
How does an injury lead to a dead tooth?
An injury can damage the pulp of a tooth, and a 2022 review calls trauma a major cause of tooth discolouration.
A 2024 systematic review of adult front teeth pushed sideways out of position (lateral luxation) found pulp necrosis in 58% with fully formed roots and 12% with roots still forming, rating the evidence very low for 14 of its 15 outcomes.
Alder Hey Children's NHS Foundation Trust guidance says it is very important that dental injuries are followed up regularly by a dentist.
Can a dark tooth be infected without any symptoms?
A non-vital tooth can be infected at the root tip without causing symptoms, and it may still need treatment.
The European Society of Endodontology 2023 guideline, summarised in the British Dental Journal in 2025, says apical periodontitis, inflammation at the root tip, may be symptomatic or asymptomatic. It is principally caused by bacteria and can lead to extraction if appropriate and timely root canal treatment is not carried out.
Infection can also cause a dental abscess, which NHS guidance describes as a build-up of pus in the teeth or gums that needs urgent treatment by a dentist and will not go away on its own. It advises:
- If you think you have a dental abscess, ask for an urgent dentist appointment or get help from NHS 111. Do not go to a GP surgery, as they will not be able to give you dental treatment.
- In an emergency or out of hours, call your dentist; if they are closed, their answerphone may tell you what to do. If you do not have a dentist or cannot get to an emergency appointment, call 111 or get help from 111 online, or find a dentist near you and ask if you can have an emergency appointment. You may have to pay for your appointment.
- Call 999 or go to A&E if you are finding it hard to breathe, speak or swallow, have a swollen or painful eye or suddenly start having problems with your eyesight, have a lot of swelling in your mouth, or are finding it hard to open your mouth. Do not drive to A&E: ask someone to drive you or call 999 and ask for an ambulance. Bring any medicines you take with you.
How do dentists test whether a tooth is still alive?
In general, dentists use pulp tests to judge whether a tooth is alive or non-vital, and X-rays to look for infection at the root tip.
A 2009 International Journal of Dentistry review says the usual cold and electric pulp tests judge pulp health from the nerve's response, and warns that false results from any pulp test can lead to misdiagnosis and incorrect, inappropriate or unnecessary treatment.
For suspected pulpitis (an inflamed pulp), the European Society of Endodontology guideline suggests cold testing, possibly supplemented by electric pulp testing, to assess vitality. For suspected apical periodontitis, it strongly recommends routine periapical dental X-rays.
To ask about a dark or dead tooth, book online or call 0114 288 2121.
What comes first, the infection or the colour?
In general, a dead or infected pulp is dealt with before the colour of the tooth.
A 2022 review says pulp vitality, any previous root canal treatment, and signs and symptoms of infection decide whether whitening from the outside or the inside is advised.
NHS guidance says an infected tooth without root canal treatment may need to be taken out. For a restorable tooth with apical periodontitis, the European Society of Endodontology guideline prefers root canal treatment, an appropriate restoration and supportive aftercare to extraction. Separate pages cover treating an infected tooth to save it, and deciding whether to save or remove a tooth.
What can improve the colour of a dead tooth?
In general, once the pulp and any infection are treated, a dead tooth can be lightened from the inside or covered.
A 2022 review describes internal bleaching for root-filled teeth, and covering the tooth with a composite or ceramic veneer or a crown. It says patients should be told bleaching outcomes are not predictable and complete restoration of colour is not always possible, and that crowns and veneers are more invasive, involve loss of tooth structure and bring a life cycle of further treatment.
Separate pages explain internal teeth whitening, porcelain veneers and the dental crown, which NHS guidance describes as a cap that completely covers a real tooth.
Frequently asked questions
Can a dark tooth go back to its normal colour?
Sometimes. A 2022 review notes that injured teeth which keep their vitality may regain normal colour, and a 2009 review cites a reported case of a stained, injured upper front tooth that later returned to normal colour. Even so, show a darkened tooth to a dentist.
Is a grey tooth always a dead tooth?
Not always. A 2020 meta-analysis of 367 injured adult teeth found a significant association between crown discolouration and pulp necrosis, but rated the certainty of evidence very low and said the result should be viewed with caution. A dentist checks the cause.
Can an injured tooth change colour without dying?
Yes. After injury the pulp space can narrow markedly (pulp canal obliteration), which can discolour a tooth; a 2024 meta-analysis found it in 27.6% of injured adult teeth. A 2026 review says it does not by itself mean pulp necrosis and often reflects healing, but advises monitoring: 8.5% of affected incisors in one long-term study developed root-tip lesions.
Why can a dentist not always tell straight away if an injured tooth has died?
An injured pulp may stop responding. A 2009 review says injured teeth can give no response to cold for a period, and clinical observations suggest it can take at least 4 to 6 weeks before tests are valid. The same review says blood-flow tests look promising but are not yet the standard test.
Can an injured baby tooth affect the adult tooth underneath?
It can. Alder Hey Children's NHS Foundation Trust guidance says an injured or infected baby tooth may affect the adult tooth developing underneath, with changes in appearance or shape such as pits or dark marks, or it may come through slower or not at all. Monitoring by a dentist is advised.
Book a consultation.
Online in under a minute, or call and speak to a real person.
Book online or call. The practice, at 334 Manchester Road, Deepcar, Sheffield, S36 2RH, is open 8am to 8pm, Monday to Sunday, with free parking outside. Fees are on the treatment costs page, feedback is in our patient reviews, and other tooth changes are covered among the restorative signs in this section.
334 Manchester Road
Deepcar, Sheffield S36 2RH
0114 288 2121
Contact us
Opening hours
Open 8am to 8pm, seven days
Free parking at the door