Cosmetic Dentistry Blog Cosmetic and General Dentistry Questions Answered

September 22, 2018

A crown or a veneer on a front root canal tooth?


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Hello Doctor Hall. About 2 years ago I had a root canal on a front tooth. I had a general dentist do the root canal. It wasn’t painful and I was very happy. He wanted to put a veneer on the tooth for a very low price. But, I decided not to do the restoration at that time.

I didn’t realize that lack of blood flow to the tooth would make it change color and about a year ago it started to change. I eventually had a porcelain crown put on by another general dentist. She filed down the tooth to a small fang and it really bothered me at the time. So far, the crown is stable. But I know these things don’t last forever. I just want to know if I was duped by the second dentist who did the crown rather than a veneer? Thank you for your time.
Gary from Florida

Gary,
I have a couple of points in response to your question.

First, about the choice of a crown versus a veneer. The simple answer that is taught in dental school to the question, “How do we restore a tooth after a root canal treatment?” is, “Do a crown.” Dental schools really don’t get into doing veneers much. So I wouldn’t say that the second dentist “duped” you—she just did what she was probably taught. But yes, it can be unsettling to have your front tooth ground down to a stub in preparation for a crown.

Here’s the explanation for that. Most teeth, when they need a root canal treatment, have an extensive amount of tooth structure missing and they really need a crown. I take it, from your initial decision to not do a restoration, that your tooth did not have extensive decay or a large break. Maybe it was just bumped in an accident. Also, after a root canal, a tooth tends to become more brittle and subject to fracture. A crown helps protect against fracture of the tooth.

But there is a difference here in the needs between a front tooth and a back tooth. Back teeth have chewing surfaces and cusps, and when you bite down, the pressure on the cusps tends to push them apart. Thus, when a back tooth breaks, it will likely split between the cusps. A crown will prevent that type of break.

Front teeth are subject to different stresses. There is no chewing surface, and the stress on a front tooth is almost all lateral. When you bite together, the lower front teeth push forward on the uppers, and the upper front teeth push backward on the lowers. Also, if you get hit in the face, the impact on the upper front teeth will be a lateral impact. Thus the most likely break of a front root canal tooth is snapping off at the gumline. A crown preparation, which will involve taking off about a millimeter of tooth structure all the way around, will actually weaken a tooth against this type of stress.

Here is a photograph of a crown preparation for a front tooth. This is a very conservative preparation. Most dentists will be more aggressive than this in removing tooth structure. But even with this conservative preparation, you can see that the natural tooth is going to be much stronger in resisting breaking off because of the thicker neck of the tooth.

photograph of a smile, showing the patient's left front tooth ground down and prepared for a crown

A veneer would leave the tooth much stronger. To prepare a tooth for a porcelain veneer, a dentist has to only remove about half a millimeter of enamel, and from the front of the tooth only. Below is a photograph of two front teeth prepared for porcelain veneers.
two front teeth, prepared for porcelain veneers, showing about half a millimeter of enamel removed

So why don’t most general dentists do veneers on front root canal teeth? With a much thinner layer of porcelain, it requires more skill on the part of both the dentist and the laboratory technician to block out the darker color of the underlying tooth. Most general dentists really don’t know how to do that.

Moving on from that point, I also wanted to make a comment about the discoloration of the tooth. It isn’t widely known that the source of the vast majority of the discoloration of a front root canal tooth is not the tooth drying out, but it comes from the root canal filling materials that are used inside the tooth. When I did a root canal treatment on a front tooth, I would clean out all the root canal filling materials from the inside of the crown of the tooth, place a white fiberglass post down into the root to strengthen the tooth, and then seal the opening I had made into the tooth using composite filling material. With that type of treatment, it could be five or ten years before any discoloration would set in and the tooth would need a veneer.

– Dr. Hall

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About David A. Hall

Dr. David Hall was one of the first 40 accredited cosmetic dentists in the world. He practiced cosmetic dentistry in Iowa, and in 1990 earned his accreditation with the American Academy of Cosmetic Dentistry. He is now president of Infinity Dental Web, a company in Mesa, Arizona that does complete Internet marketing for dentists.

September 6, 2018

Matching the color on a crown for a front tooth


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Hi Dr. Hall,
I had a root canal done on my front tooth over 10 years ago. In the past few years I had noticed a blue discoloration at the top of the tooth. After trying internal bleaching, my dentist ended up doing a crown.

The first crown that came back from the lab looked very white. He redid it. The next tooth, which is in my mouth now, looks better but doesn’t match the other front tooth. The dentist permanently cemented it in, but when I got home and took some selfies I was unhappy with how unnaturally white it looks.

The dentist will give it another try but my question is — should I let him try again or go to someone else who specializes in cosmetic dentistry? I now live in Princeton, NJ and my dentist is in Brooklyn. Cost is a factor.
Thanks,
Ronnie

Ronnie,
Doing a crown on a single front tooth is a tricky procedure. The slightest variation in color between the two front teeth is usually very noticeable. And it isn’t just the overall color—any tooth has multiple colors in it. Even expert cosmetic dentists will often have multiple try-ins before they get the crown to match perfectly. When I was in practice, I charged about 40% more for crowning a single front tooth because we would typically send it back to the lab three or four times until we got it perfect and I would charge the extra fee because of all the extra appointments. Dentists with poor cosmetic dentistry skills sometimes ask patients to crown both front teeth in order to get the color right.

That your dentist would think that the crown would look right after one or two trips to the lab shows either inexperience or a low level of commitment to excellent cosmetic dentistry. I’m not meaning to imply condemnation with that comment because that is typical of the overwhelming majority of dentists—maybe 98% of them. So yes, if you want this done so that your two front teeth match perfectly, you need to raise your sights and go to an excellent cosmetic dentist such as we recommend. There are several excellent ones within reasonable driving distance of Princeton, say 15-30 miles.

However, depending on how big a factor cost is for you, and if your dentist is willing to work with you to get this right for no extra charge, you may want to stick with this dentist to save the money of having another dentist start over with you. And, I would add, if you are willing to make several more trips back to Brooklyn. To help the process, you or the dentist should get hold of a good digital camera that is capable of taking a clear photograph of the new crown in place next to your natural tooth under outside light, such as right next to a window. That will go a long way toward helping the ceramist pin down the right color. And be sure that the crown is only temporarily cemented until you have seen it under various lighting conditions.

If you want perfection—a crown so natural that you can’t distinguish it from the real tooth next to it—you need the expert cosmetic dentist. But if you are willing to accept some compromise of that ideal in order to save money—try letting your dentist have some more tries to get this closer.
– Dr. Hall

Do you have a comment or anything else to add? We’d love to hear from you. Enter your comment below.

Click here to ask Dr. Hall a question of your own.

About David A. Hall

Dr. David Hall was one of the first 40 accredited cosmetic dentists in the world. He practiced cosmetic dentistry in Iowa, and in 1990 earned his accreditation with the American Academy of Cosmetic Dentistry. He is now president of Infinity Dental Web, a company in Mesa, Arizona that does complete Internet marketing for dentists.

March 2, 2013

Do you need a crown on a front tooth with a root canal treatment?

Just had a root canal on the tooth right next to the front tooth. Is it necessary for a crown to be put on ? Can a post only be put in and if so, repair the discoloration with a porcelain veneer ?
– Ann from New York

Ann,
There’s a simple answer to your question and a more thoughtful answer, and I’ll give you both.

The simple answer is that dentists were taught in dental school that if a tooth has a root canal treatment, it is weakened, and thus it needs a crown to strengthen it and prevent tooth fracture. Plus, after a root canal treatment, a tooth will turn dark, so a front tooth should have a crown to preserve its appearance.

The more thoughtful answer differs from this approach in two ways. First, on the “likelihood to break” issue:
– Yes, a tooth is weaker after it has had a root canal treatment. But there is a difference between back teeth and front teeth. Back teeth, because they have a flat chewing surface and cusps are prone to splitting – the chewing force comes down between the cusps and this pressure tends to force the cusps apart. A crown will prevent splitting of the tooth. A front tooth, however, doesn’t have these forces. The risk with a front tooth is that chewing creates a horizontal force that may break off the tooth. A crown, since it requires removing 1-2 millimeters all around the circumference of the tooth, will actually weaken it against these horizontal shear forces and make it MORE likely to fracture.

On the discoloration issue, yes, teeth with root canal treatments will discolor. However, if the root canal cement and the root canal filling material are carefully cleaned out of the inside of the crown of the treated tooth, that discoloration will take years to occur and will be mild.

My preference for a front tooth would depend on the amount of healthy tooth structure remaining in the tooth. If, say, 70-80% of the tooth is healthy tooth structure, I would recommend restoring the tooth simply with a translucent or white fiberglass post and composite. Then, when the tooth begins to discolor, that could be corrected with a porcelain veneer or a crown at that point. If substantial amounts of tooth structure are missing, I would use the same white or translucent post with an all-ceramic crown.

Dr. Hall

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About David A. Hall

Dr. David Hall was one of the first 40 accredited cosmetic dentists in the world. He practiced cosmetic dentistry in Iowa, and in 1990 earned his accreditation with the American Academy of Cosmetic Dentistry. He is now president of Infinity Dental Web, a company in Mesa, Arizona that does complete Internet marketing for dentists.

April 24, 2012

Tips for root canal treatment on a porcelain veneer tooth

Dr. Hall, For the past two months I have been experiencing slight pain, pressure, discomfort and even feeling as if my two front teeth are going to fall off. Hot or Cold do not bother my teeth. Approximately 9 years ago I chipped one and also had decay on my two front teeth. As a result, veneers were placed. Never had any problems until now. I went to a dentist that has been doing my cleanings and she did an x-ray and noticed inflammation on a nerve. Advised to take ibuprofen for 7 days for inflammation. I followed her instruction and it did work for 1-2 weeks until the same symptoms came back. I went back she took another x-ray, noticed the same inflammation. She stated if it continued then possible root canal would be the next step. However nerve had no damage, which it confused me as why she would do a root canal? I was advised from a friend that sometimes the nerve can be infected. I had some amoxicillin at home and took it for 5 days the pain once again was gone. Now 2 weeks later symptoms are back. My biggest fear is that veneers are going to fall off, is that possible? Even saliva feels weird around my front teeth only. Can you tell me if it may be possible for root canal?
– Sylvia from California

Sylvia,
I’m at a little bit of a disadvantage not being able to see this myself, but at least from what you’re telling me it seems pretty clear that your tooth needs a root canal treatment. And I will tell you why I think that.

I am interpreting the “inflammation on a nerve” that you are telling me about as signs on the x-ray of pulpal inflammation. When the pulp of a tooth is inflamed, often the first sign is either a widening of the periodontal ligament space around the end of the root, or a breakdown in the bony lining of the socket of the tooth, also occurring at the end of the root. When anything shows up on the x-ray like this that indicates inflammation of the pulp of the tooth, it is pretty certain that you are going to sooner or later need to have that root canal treatment.

Taking some amoxicillin you had at home for a tooth infection isn’t a good idea. But the response of your tooth – the pain went away and then came back two weeks later – is another pretty certain indication that the tooth is infected, which means you need a root canal treatment. The problem with having taken the amoxicillin is that now you are that much more likely to have an amoxicillin-resistant infection in your tooth. You can never wipe out a tooth infection with antibiotics alone because the antibiotics have no way to get inside the tooth. So the infection will always come back, and the next time it’s always more likely to be an antibiotic-resistant infection.

Your porcelain veneer won’t fall off this tooth if you get a root canal treatment. But let me give you some helpful advice on how to have this done so that you preserve the esthetics of your smile. And this is something that many dentists don’t know, unless they are really expert in appearance-related dentistry. There is a strong potential for a tooth with a root canal treatment to turn dark. That dark color will show through the porcelain veneer and will require it to be done over again unless the dentist takes this simple precaution. After the root canal treatment, the dentist needs to clean out all root canal filling materials and cement from the insides of the visible part of the tooth – the part that shows above the gumline. Then she should cement a translucent fiberglass post inside the tooth to reinforce it and fill up the rest of the inside of the tooth with a light-colored composite material that will preserve the original color of the tooth. It is the root canal filling material and cement inside that cause most of the discoloration of the tooth. But by cleaning all that out and filling it as I have described, it won’t permanently prevent any discoloration of the tooth, but it may put it off for a good five to ten years. At that point you can get new porcelain veneers or go to a crown on the tooth.

Show this e-mail to your dentist, and she can contact me if she has any further questions.

Having this delayed response to the traumatic injury and decay you experienced 9 years ago isn’t unusual at all. Most dentists have seen this sort of thing before.

Dr. Hall

We thank our advertisers who help fund this site.

About David A. Hall

Dr. David Hall was one of the first 40 accredited cosmetic dentists in the world. He practiced cosmetic dentistry in Iowa, and in 1990 earned his accreditation with the American Academy of Cosmetic Dentistry. He is now president of Infinity Dental Web, a company in Mesa, Arizona that does complete Internet marketing for dentists.

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