Black Lines on Teeth and the Need for Root Canal Treatment

Q: Black Lines on Teeth and the Need for Root Canal Treatment

Hello： 1. <br>The dark line may be secondary caries or simply food staining, and it could also be necrotic dentin intentionally left during the initial treatment. <br>2. <br>The source of infection for the abscess is mostly due to pulp necrosis, but it can also originate from bac

Black lines on teeth and root canal treatment?

Dear Dr.
Lin,
About ten years ago, I had a large cavity filled between my upper left first and second premolars.
At that time, the dentist mentioned that the cavity was quite deep and was unsure if it had reached the nerve.
They suggested to proceed with the filling, but if it didn't work, I might need a root canal treatment.
However, I have not undergone a root canal treatment to this day.
I would like to ask you the following questions:
1.
After the cavity was filled, I noticed a "bruise-like" black line appearing in the middle of my upper left second premolar after some time.
It has been present for quite a while but hasn't changed much.
In your opinion, what could this "bruise-like" black line possibly be?
2.
During a routine dental check-up in early 2018, a small abscess appeared on the gum above my upper left first and second premolars.
The treating dentist indicated that the nerve might be starting to necrose and there was inflammation, recommending a root canal treatment.
Given that the cavity had been excavated and filled, and I have not had any cavities for over ten years, how could the nerve still be necrosing and inflamed?
3.
Following that, I did not proceed with the root canal treatment and continued to monitor the situation.
By mid-2018, during my routine dental check-up (every six months), the small abscess had disappeared, and the treating dentist suggested that we could continue to observe.
As of yesterday's routine dental check-up, there was still no sign of the abscess.
In your opinion, is it still "necessary" for me to undergo root canal treatment? Or should it be done but is not urgent, allowing for further observation?
Thank you, Dr.
Lin.

Axiang, 30~39 year old female. Ask Date: 2020/01/22

Dr. Lin Jiayong reply Dentistry

Hello: 1.
The dark line may be secondary caries or simply food staining, and it could also be necrotic dentin intentionally left during the initial treatment.
2.
The source of infection for the abscess is mostly due to pulp necrosis, but it can also originate from bacteria in the gums, periodontal tissues, and alveolar bone.
Therefore, it is necessary to use X-rays to confirm the source of infection.
3.
It is recommended that you ask your dentist to take periapical X-rays every six months to monitor the condition of the pulp and periodontal tissues, and then decide when to intervene with root canal treatment.
Thank you.

Reply Date: 2020/01/22

More Info

When it comes to understanding the implications of black lines on teeth and the necessity for root canal treatment, several factors must be considered. Based on your description, it appears that you have experienced a complex dental situation involving previous cavities, potential nerve damage, and the presence of a black line resembling a bruise on your tooth.

1. Understanding the Black Line: The black line you mentioned could be indicative of several issues. It may represent secondary caries (cavities that develop under or around existing fillings), or it could simply be staining from food or beverages. In some cases, it might also be related to necrotic dental pulp, where dead tissue remains within the tooth structure. If the black line has been stable for a long time and has not changed, it may not be an immediate concern, but it should still be monitored. Regular dental check-ups and X-rays can help determine the nature of this discoloration.

2. Nerve Damage and Inflammation: The presence of a small abscess or pus pocket above your teeth during your dental check-up indicates that there may be an infection, often stemming from necrotic pulp tissue. Even if you had a cavity filled years ago, the nerve can still become damaged due to various reasons, such as trauma, deep decay, or even the presence of bacteria that can infiltrate the pulp chamber. This can lead to pulp necrosis, resulting in inflammation and infection, which may not always be immediately evident. The fact that you have not experienced pain does not rule out the possibility of nerve damage or infection.

3. Need for Root Canal Treatment: Given that the abscess has resolved and there are no current symptoms, it may seem reasonable to postpone root canal treatment. However, it is crucial to understand that the underlying issue may still exist. Root canal treatment is often recommended to prevent further complications, such as the spread of infection or tooth loss. Regular monitoring through X-rays and dental examinations is essential. If any new symptoms arise, such as pain, swelling, or the reappearance of the abscess, it would be prudent to proceed with the treatment.

In summary, while your current situation may not necessitate immediate root canal treatment, it is essential to maintain regular dental visits for monitoring. If the black line changes or if you experience any discomfort, it would be wise to consult your dentist for further evaluation. Root canal treatment is a common procedure that can save a tooth and alleviate potential complications in the future. Always prioritize open communication with your dental care provider to ensure the best course of action for your oral health.

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