I had a crown on one of my back teeth pop out the other day and was wondering: Is there any harm in gluing it back on with superglue?
It’s not so much that I am afraid of dentists, I just dread taking the time to make an appt and waste half a day to have them glue it back on themselves. It seems so much easier just to pop it back on myself. What type of adhesive do the dentists use, anyway?
Disclaimer - IANAD
Call your dentist. Crowns do not pop off without a reason. There could be decay or there may have been an open margin, causing the cement to wash out. If there is no decay recementing can take as little as 15-20 minutes.
Superglue will wash out, allowing bacteria under the crown and fluids in again. My office uses a hybrid glass-ionomer (more info than anyone needs here .pdf file) or a self-cure resin cement, depending on crown composition. They are fairly impervious to moisture when set.
Again, call your dentist, and do it soon. Your teeth can shift just enough in a few days to make recementing the crown a bit difficult.
IIRC, the active ingredient in superglue (ethyl cyanoacrylate) is toxic. That means do not put it in your mouth.
You REALLY should call your dentist. Teeth are not toys! The glue that dentist’s use is WAY stronger than superglue, and it’s way easier for them to glue it on right, than you to try to do it yourself. Imagine explaining to your friends why your tongue is glued to the inside of your cheek! 
http://www.wpiinc.com/WPI_Web/Lab/Superglue.html
That site doesn’t exactly apply to your situation, but it’s pretty close. It explains why superglue can’t be used to bond “live animals.” Sorry if I came across as harsh, but I’d hate for you to hurt yourself or make your situation worse than it already is.
Actually you can go to any drug store and find a temp cement for your fillings. I had a bridge done and I am waiting to put the final bridge in. While I was waiting I lost my job. So I didn’t want to pay 1,000.00 while unemployed. My temp bridge fell out and I put it back in with the drug store temp cement and (knock wood) it is still holding. It should hold long enough for you to go to the dentist.
Of course you can’t eat ANYTHING sticky on it, as that’ll pull it back out.
Also if it was a root canal and the cap popped out and the stem and everything is in your mouth, that is most likely simple to replace. If the stem is in your cap, your root canal failed and should not be put off, I put mine off and that is why I have a bridge now.
In the above post I said cement for fillings but I ment caps. Well actually you can find temp replacements for fillings too,
OK, so superglue is out, I figured as much. I have to find a new dentist since the one that put in the crown is in another state. It doesn’t hurt or anything. But this brings up another question…
How long should a crown last? I have only had this one in for like 2 years, maybe less, and even with insurance I paid like $200 to have it done. Is this something I’m going to have to deal with every other year? I’m just glad I didn’t swallow the crown when it came off!!
I’ll check out that temp cement while I’m getting an appt set up. In what section of the drugstore will I find it?
Thanks for your help, guys!!