My porcelain crown keeps falling out.

I have porcelain crowns on some of my top teeth. I have had problems with them falling out. This weekend I was eating something and bit down and I didn’t know my tooth fell out – I bit down on it – it shattered and apparently I swallowed most of it. I had it done at my family dentist in 2004 and have been back there several times to have crowns re-cemented in. He usually doesn’t charge me to re-cement but now he wants to charge me $1,100.00 for a new crown. I told him I would pay cost for the crown but that was it, that it should not have fallen out to start with. Is it common to have them fall out as much as mine have? Is this something that I have to pay for?
- Susan from Georgia

Susan,
No, this shouldn’t be expected, that a porcelain crown keeps falling out. If they’re done right they won’t ever fall out. But I can understand why your dentist wants to charge for this, because now he has to make it from scratch, and it’s kind of expensive for him to do this.

What holds crowns in is the near parallelism of the way the tooth is prepared. The more parallel the tooth is prepared, the stronger is the retention. But if the tooth walls are made TOO parallel, there is a risk of what are called undercuts, and the crown won’t fit at all. Different dentists have different levels of comfort with how parallel they will make their preparations. The less parallel they are made, the easier it is to fit the crown.

But then with all-porcelain crowns, they are also bonded to the teeth. And if they are properly bonded, they don’t need a lot of retention in the design.

I’m suspecting that your dentist doesn’t know how to bond porcelain crowns. They’re supposed to be bonded to your tooth, and they get most of their strength from the bonding procedure. It sounds like your dentist has simply cemented it in instead of bonding, as that’s the only reason I could think that an all-porcelain crown would just fall out like that.

Yes, I would say that your dentist should just replace this for no charge. But I don’t believe he’s legally required to do this, and if he has lots of these crowns falling out, I imagine he’s getting tired of doing this for free, and it’s hurting his bottom line.

Comments are closed.