Why is my New Crown Breaking the 3rd Time?

Hi MD.  Good question.  In your case, since you had a crown for 7 years without any fractruing issues, we could make the assumption that there is a problem with the material used to make the new crown.

Either the wrong material was used (a more esthetic, but weaker material used for crowns on front teeth) or the lab processed the material incorrectly.

Like all dentists, I have had new crowns break for various reasons. Trying to figure out what the problem was and replace the crown is standard.  But if the same thing keeps happening, you might want to consider that your dentist is not recognizing what is causing the problem.  It happens, and it may mean its just time to move on.

Hope this helps.

Best,

Dr. Alper

Why was your 7yr old crown re-done? The fact that you had this old crown for so long without any problem tells me that the problem is not your bite or dietary habits. Mostly likely cause is material or laboratory failure. Find out what kind of crown you had before and what kind the new one is.

There are newer materials that tend to be more esthetic but they are not long term proven. Also, newer materials need special hadling and bonding by the lab tech and by the doctor. The dentist is responsible for the quality of the lab they use. I would recommend that if they cannot get it right, you ask for a refund and go somewhere else for your crown. Maybe ask them to use the same type you had before.

Good luck

Dr. T

Breaking of your crown can be attributed to laboratory part of fabrication of the crown such as poor fabrication technique or materials, or clinical part of fabrication which would be incorrect occlusal record or insuficient occlusal adjustment. Regardless of the reason I would reccomend you to go back to your restorative doctor and ask for solution of this problem. Good luck!

One of 2 reasons: The laboratory being used is a "cut-rate" overseas lab, that uses inferior materials. Or, there is a severe issue with your bite (occlusion). If your muscles want your teeth to meet differently than how the crown meets its opposing tooth, then the muscles will win the battle, and the crown will break.

Hard to tell by the description.  It may be the material of the crown that the dentist is using, could be there is not enough room for the material if the tooth was not prepare sufficiently.  I would get a second opinion from another dentist if you needs are not being me by your dentist. 

Crowns shouldn't crack.  It is probably not your dentists fault directly.  If his lab doesn't treat the materials correctly it becomes vulnerable to fracture.  Porcelain has to be treated in a very in a very specific way with regard to heating and cooling the material.  eMAX is an excellent material and I have had no fractures even in difficult situations.  Finding a good lab is a big challenge.  I'd give your dentist another chance and discuss a new lab with him.  Hopefully he will be open to the idea.

From your description it sounds like most likely the crown is all-ceramic. The major reason for the breaking of new crown will be the bite and contacts between upper and lower teeth during side movements of the jaws. This should be checked and corrected before the crown is cemented, the occlusion should be adjusted. It also can be the poor material used by the lab. You need to address this issue with your dentist. 

Some materials are not appropriate for some mouths.  The material least likely to fracture is a full gold crown, but most people do not want that.  A combination porcelain with gold is a good option as well, but the porcelain can fracture off of the gold too, so it isn't perfect.

 

It is also possible that your bite has undiagnosed issues and should be evaluated as well.