So, today I went back to the dentist. I asked him if there was enough tooth left for the crown to grip and whether the prep was adequate. He re-examined it and said, "Definitely." He also checked for inflammation, infection, sinus problems, protruding gums, bite problems, and other things that could possibly have interfered with the crown staying put, and found none.
He then told me that he couldn't come up with any reason for the crown not staying put other than that it didn't fit quite right. He said the most common reason for that is when the patient doesn't stay perfectly still while the impression is hardening, but that it could also be just a less-than-perfect job by the lab, or a less-than-perfect job of taking the impressions on his part. He then took three -- count 'em, three -- sets of impressions and told me he was ordering a new crown. I asked why so many sets of impressions, and he said he wanted to rule out things like imperfections due to air bubbles. I guess he plans to send all three to the lab. Or maybe he just didn't like the looks of the first two.
Then he re-cemented the loose crown back in using yet another kind of cement. He said something about people's mouths having different pH balances, and some cements working better than others for different people. He also said that if that's the problem, he might actually have a hard time getting the crown out to put the new one in, in which case I could choose to just leave it in if I wanted.
That sounded a bit fishy to me, but what do I know. I guess what I'll do is wait about ten days (the crowns usually come in from the lab in about 14 days) and then give it a bit of a tug or eat something chewy to see if it still feels solid. I must say that it
does feel a lot more solid with the new cement, but it's only been seven hours and I haven't chewed on that side. He also told me that this particular cement takes about two hours to cure, if that means anything.
I meant to ask why he wasn't putting in a temporary instead of the crown that has been falling out, but I got sidetracked into the discussion of the different cements and the pH of different mouths, and before I had a chance to ask, he'd already stuck the crown back on. So I guess now there's nothing left to do but wait.
Oh, and he said there would be no charge for any of this.
All I can say is that he certainly seems to want this crown to fit happily into my mouth, and he did seem to do a pretty exhaustive investigation into why it hadn't. The thing that doesn't sit quite right with me is his mentioning that if the present crown winds up staying put with the new cement, leaving it in might be a better option. Does that make any sense? If he thinks there were imperfections, then why would it make sense to leave it in?
On the other hand, if it does stay put, then I guess it wouldn't make sense to take it out at that point. Kind of like "if it ain't broke, don't fix it." Maybe the pH thing was the problem all along. Except that the other crown he did is nice and tight.
This is giving me a headache. But at least it's not giving me a toothache.
Rich