When Does a Tooth with a Root Canal Treatment Need a Crown?

I have a root canal treatment that has never been crowned. Recently, I read that is a mistake. Should I get this crowned? I used to have dental insurance, but now I don’t so I don’t want to spend the money if I don’t have to. What are your thoughts on it?

Bruce

Dear Bruce,

I’m very glad this question came up because I have seen some people just crown every tooth that had a root canal. In some cases that can do more harm than good. Much of the answer to this question will depend on which tooth you are talking about. If it is a back tooth, such as a molar, then I would say to crown the tooth. It will protect it from the type of biting forces those teeth face. With other teeth, it gets more complicated.

illustration of a a front tooth

The biting stresses on a front tooth and their adjacent teeth are mostly horizontal because of the tearing stress. This means the neck of the tooth is the most vulnerable. By the time you prepare a tooth for a dental crown, it loses a minimum of 30% of its diameter, putting additional stress at the neck of the tooth. If that tooth also lost a significant amount of structure before the root canal treatment because of decay, there will be even less structure there.

If you place a dental crown on a front tooth that doesn’t have the necessary diameter to support the forces it is subjected to, it could end up breaking at the gumline. Some dentists try to overcome this by placing a post in the tooth, though that can increase the chances of the root fracturing, which will require an expensive repair.

The issue with front teeth after a root canal is that they tend to turn dark, which becomes an appearance issue. Our smiles are one of the first things people notice about us so we want them to look as nice as we can. Here is my advice on how to keep its white color longer and what to do when it does turn dark.

Helping a Tooth with a Root Canal Keep its Color

Your dentist needs to thoroughly clean out any root canal material and cement from the crown of the tooth, these are huge contributors to the dark appearance. Next, he or she should place a white fiberglass post into the tooth. Fiberglass is more flexible and will help with the stress. Finally, fill the remainder of the open area with white composite filling material. Doing this will extend your tooth’s color.

If it does eventually turn dark, instead of crowing it, I would suggest a porcelain veneer placed on that tooth. That removes far less structure, which will be better for the tooth viability in the long run.

This blog is brought to you by Gilbert Dentist Dr. Matt Roper.
We treat dental emergencies.

12 Shots of Novocain to Get Me Numb

I recently had a tooth extracted. The whole procedure was a nightmare. It took twelve shots to get me numb. I don’t know how a dentist can miss a spot that many times! Have you heard of this happening before? Is there a way for a dentist to find the right spot the first time so I don’t have to go through that again?

Paula

Dear Paula,

woman wearing nitrous oxide nose piece

While it is possible that your dentist missed the spot to numb your tooth over and over again, it is much more likely that you had some dental anxiety in the beginning which worked against your numbing medication. Then, as you were still in pain, your anxiety went up even more, creating a vicious cycle. There are too many dentists who do not realize the link between anxiety and the inability to get numb in the dental chair.

The simplest solution to this is to find a dentist who offers dental sedation options. It may be all you need is some nitrous oxide, which is administered with a nose piece, as in the image above. This can relax you enough to enable the Novocain to do its job properly. However, if your level of anxiety is super high, you will be better served with oral conscious sedation. This is significantly stronger, in fact, you will likely sleep through the entire appointment. Be aware though, that it is so strong you will need someone to drive you to and from your dental appointment. You will not be able to do this on your own.

Those who have dental anxiety have found that by using the appropriate level of sedation for stressful dental procedures, they are able to have stress-free as well as pain-free dental appointments.

Dealing with a Missing Tooth

You didn’t mention what tooth was extracted. In most cases, it will be very important to replace the tooth. This isn’t just for appearances sake, though that is important. Without that space being filled, the adjacent teeth will start to drift or tip into the empty space. This will throw off your bite, which can lead to painful jaw problems and even daily migraines.

The best option for replacing a single tooth is a dental implant. This is what I would recommend to a patient of mine.

This blog is brought to you Gilbert Dentist Dr. Matt Roper.