The Cosmetic Dentistry Blog

Dr. Hall,
My employer assures me the radiolucent images of his Cerec crown margins are just radiographic burn-out and not poor margins. Can you support this?
- a dental hygienist

Dear Hygienist,
It’s possible that a radiolucency at the margins of your CEREC crown are from radiographic burn-out. A better x-ray may help tell for sure.

If it is a gap at the margin, it should be clearly defined – you should be able to tell distinctly and precisely where the radiolucency begins and where it ends. If it is fuzzy – it just gradually fades into the tooth – then it’s probably radiographic burn-out. You may want to ask another dentist to look at it for you, if you have doubts.
- Dr. Hall

Related links:
Read about the new DURAthin veneers

Hello Dr. Hall
I’m having a crown put on one of my rear molars. The dentist says it’s not possible to use porcelain due to the size. Something about how there is not enough space. So they’ve given me the option of metal or gold. Is this possible? I read that metal takes more space than porcelain. I don’t want metal, if at all possible.

Thank you,
- Rose from California

Rose,
When porcelain is used in a crown, it does have to be thicker than metal. And in some situations, on second molars, there is very little space to work with. I can understand why your dentist would want to use a metal crown if space is limited in your mouth.

There are various options for a metal crown. Gold is the most common metal because it is corrosion-resistant, and can be cast to a fine finish line so that it fits better than any other type of crown. If you have to have a metal crown, I would highly recommend gold. It might cost more, but you will get many more years of service out of your typical gold crown than any other metal.
- Dr. Hall

Dr. Hall,
If a temporary crown falls off will a little toothpaste or vaseline re-activate it?
- Marlene from California

Marlene,
I’m assuming you’re asking how to fasten the temporary crown back on  your teeth. You’re smart to know that you need to have this temporary crown back on. It is possible for your tooth to get damaged if it is exposed for several days without the temporary crown on. Also, your teeth will drift together and make it so your permanent crown won’t fit, meaning that you will have to go back through the entire crown preparation process again and get another crown made, and your dentist may charge extra for that.

Toothpaste or vaseline won’t hold the temporary crown. Actually, my opinion is that your dentist should assume the responsibility for re-cementing your temporary crown for no charge. I think most dentists do that. That’s the best option.

Three other options if you can’t get in to see your dentist:
Superglue. It will hold things on your teeth quite well. But beware – you could complicate the final treatment because of problems in cleaning off the superglue later. So only do this if you call your dentist and she or he says it’s okay.

Denture adhesive. This will hold fairly decently.

Drug stores often have temporary dental cement to help hold on temporary crowns.

I hope this is helpful,
Dr. Hall

Related links:
Read about dental crowns in general and porcelain crowns in particular.
Cerec crowns don’t require a second appointment, so no temporary crown is necessary.

Dr. Hall,
My last dentist said that I needed a crown on the very back molar on the top left side. A root canal was not done beforehand, however.

Subsequently, about 10 months post-crown, I accidentally was grinding my teeth and broke the porcelain off. First, is it common to crown a live tooth? I had never heard of that before. Secondly, when I look up at the molar now it is pitch black, and when I asked the Doctor, he said not to worry about it, that it was more or less cosmetic but would not pose any sort of health hazard. What do you think? Thank you in advance for your advice!
Sincerely,
-Steve from Minnesota

Steve,
First, yes, it is common practice to crown a tooth that doesn’t have a root canal treatment. Anytime there is a significant risk that a tooth might break, it is prudent to have a crown put on it. The connection with root canal treatment is that when a root canal treatment is done, it makes the tooth much more susceptible to breaking and so, especially with a back tooth, a crown is almost always in order.

Second, about the porcelain chipping off. It’s an indication of problems with the laboratory work, and we don’t like it when that happens. But if there is a metal foundation under the crown it doesn’t require replacement of the crown. The metal will protect the tooth.
- Dr. Hall

Related links:
Dental crown

My husband’s dental crowns keep coming off usually within a week or two of getting them recemented. His dentist is saying there is nothing more they can do. We are thinking about implants but it doesn’t look like they stick up much…will he have the same problem with the implant crown coming off? Are there different types of glues for crowns that could be causing this problem?
- Pat in Arizona

Dear Pat,
It isn’t that hard to get crowns to stay on. I’d get a second opinion. In twenty-some years of practice, I never had a crown that I put on come uncemented and have to be recemented, once I permanently cemented them. If they are done right, they stay on.

How well crowns stay on depends on the shape of the tooth preparation. When the preparation is too tapered, it’s hard to keep the crown on. So that’s probably the problem. You may need new crowns, or a knowledgeable cosmetic dentist may be able to bond these crowns on. There are bonding agents now that bond metal, porcelain, teeth, and everything imaginable. Expert cosmetic dentists are trained in all these high-tech bonding techniques. I can’t tell you without seeing them, but this is ridiculous to put up with crowns that won’t stay on.
- Dr. Hall

Click here for referral to an expert cosmetic dentist.
Click here for information about temporary crowns, all-porcelain crowns, or Cerec crowns.
Click here to ask Dr. Hall a question.

Dr. Hall,
I had a crown on tooth 13 and a root canal on 12. Since the crown was put in, I’ve been having soreness around the gumline and discomfort with biting. Food also gets easily caught between 13 and 14. I feel the crown is in the wrong place. Can it be removed and replaced again? The dentist has tried to adjust the bite 5-6 times. Please help.
- Elsa in Virginia

Elsa,
This crown you have is a problem, but I doubt that it’s in the wrong place. It’s probably just shaped wrong.

I’m concerned as to why your dentist would adjust the bite five or six times. It’s not hard to tell if the bite is off and that should be able to be adjusted when it is put in, or certainly at the first return visit, max. Are you going in, telling him or her it hurts to bite on it, and so he or she is trying to fix that by adjusting the bite? I’m sure the bite must be right by now. I’ll bet it hurts when you bite because of the gum inflammation–that’s my guess.

Catching food between the crown and the tooth behind it, that’s a serious problem that shouldn’t be tolerated, and it may mean that the crown has to be re-done. When a crown is cemented, it can be very hard to get off, maybe even impossible, without destroying the crown. So it would need a new crown.
And the gums being sore–that’s not good. The crown is irritating the gums. That could be just because of the catching food, or it could also be that the crown doesn’t fit right at the margins or is too bulky at the margins. Do the gums hurt all the way around? or just between 13 & 14?

But re-doing the crown is going to be a big problem. If the crown didn’t fit right, the dentist shouldn’t have cemented it. If it catches food, there is probably a gap between the crown and the tooth behind it. But the dentist should have checked that when the crown was tried in and not cemented it. Now, with your gums inflamed, it’s going to be very difficult to re-do the crown because the dentist will need a new impression, and it is difficult to impossible to get a good impression in the presence of gum inflammation.

Here’s what I would do. Go back to the dentist and say:
1. That you need the crown fixed so that it doesn’t catch food.
2. You need the gums not to be sore.
3. You were told by me that this may require a new crown and that in order to get a good new impression, the gums need to be not inflamed, and the dentist needs to do whatever is necessary to get this to happen.
Good luck,
- Dr. Hall

Dr. Hall,
I had a crown procedure done on a lower molar one week ago. This is the temporary crown. For the first several days, there was some swelling and tenderness of the gum around the tooth (which I expected) and my jaw hurt to open wide. Since those things have healed and I’ve been able to chew, brush, etc. normally around the crown, I’ve been experiencing pain throughout all of my left lower teeth and in my jaw. The pain is not horrible and is relieved by ibuprofen, but it’s pretty uncomfortable. Nothing in particular seems to precipitate the pain (it is there first thing in the morning). Is this just part of the healing process? It seems to hurt more around my other teeth than the tooth that had the procedure.
- Ashley from Florida

Ashley,
The inflammation in your gum is very common. The persistent pain in the jaw to where you have to take ibuprofen to be comfortable–that isn’t that common. While this could be nothing, it is worth checking. The pain is most likely coming from your tooth, even though it feels like it is in the jaw. It is normal for a tooth to feel some trauma after a big procedure like a crown preparation. If I were your dentist, I think I would coat your tooth with some type of desensitizer sealant on the surface of the dentin to try to get the pain to go away.

When a tooth needs a dental crown, it has already been through a lot–decay and large fillings. It’s possible that this tooth has had so much trauma that the inflammation is irreversible and it will end up needing root canal treatment. Your dentist, who knows how deep the old filling was and whether or not there was decay under the filling, will be in the best position to evaluate the cause of this pain.
- Dr. Hall