Hello Mr. Carr; I'm so very sorry to hear of your continued problem with your crowned tooth. Obviously the crack your dentist detected was beyond just the old filling and crown, and I suspect it involves one or more roots of your tooth. When root cracks/fractures occur, a successful prognosis on the tooth drops dramatically. If you were my patient and came in with this continued pain, I would try to pop the crown off and do a root canal therapy on the tooth and recement the crown with a composite-hybrid cement which has been known to shrink very slightly (in micrometers) and help to close the crack. If crown won't pop off in one piece or the margins are compromised, then a new crown fabrication would be necessary. Like I said though, a fractured root will drop the possibility of long-term successful prognosis to less than 50%. I wish you all the very best of luck in getting this chronic problem resolved. Dr. Rowe

Welcome to JustAnswer, and thank you for putting your trust in me!

Please allow me to address your questions individually:

"The dentist said he cemented the porcelain crown in permanently but used Durelon instead of a newer cement and said that he could still remove the crown. I'm worried because if the crown can be removed it means to me that it isn't cemented in permanently. I am worried that the Durelon will leak out and/or infection will get in there and rot out this recently crowned molar."
A: Durelon is a permanent cement. The fact that it may be marginally softer than resin cements is irrelevant, because it is more than strong enough for the purpose of permanent cementation. In fact, the film thickness and leakage properties of polycarboxylate cements such as Durelon are superior to resin cements. Whether it may be easier to remove a crown that has been cemented with Duralon is also irrelevant, because it's darn difficult to remove a permanently cemented crown, even one that has been cemented with Durelon, without risk of damage to the tooth. The only really safe way to remove a permanently cemented crown, as you have already been told, is to cut the crown off. The issue here is not whether infection will "get in there", but whether it was already in there at the time the crown was fabricated.

"Also the dentist did not wash off and dry the tooth before cementing in the crown. I know I got saliva on the tooth and touched it with my tongue. I am worried about any bacteria on the tooth under this crown and about the bond. Would an uncleaned and undried tooth weaken the seal, making it easier for food and oxygen to enter?"
A: Although it is customary to dry a tooth prior to cementation, polycarboxylate cements are water-based, and fully miscible with water and saliva, and would not appreciably degrade the bond strength. The liquid component of polycarboxylate cement is polyacrylic acid, which has strong antimicrobial properties, and would suppress the growth of decay-causing bacteria trapped on the tooth surface.

"Please advise if I should have crown removed and re-cemented with a more permanent cement."
A: The removal and re-cementation of the crown would not be justified based on the prior use of Durelon. That does not mean that the crown might not need to be removed for other reasons.

"A few dentists have said that the only safe way to remove that crown is to cut it off, to avoid damaging my already cracked tooth. However, I have also been told by a few other dentists that durelon allows for easy removal by tapping it out."
A: I agree that removing a crown that has been previously cemented with Durelon would be neither safe nor easy. This is especially the case for a crown on a tooth with a previously discovered fracture.

"The dentist said he removed the crack but now 10 days after the crown was put on I still feel as much pain as before when I bite on something hard with this tooth and in the same place on the tooth. Therefore I am worried that the crack is still there. If however this is inflammation of the pulp/nerve, would this be something that will heal and the pain might subside? If it still hurts because of a crack, then will the crown prevent this from getting worse?"
A: This is the crux of the question. The persistence of your pain suggests that the dental pulp is injured. The fact that the symptoms have remained relatively unchanged after the treatment indicates that the pulp injury preceded the crown placement, and that the crown did nothing to address the underlying cause for your symptoms. There are a multitude of potential causes for pulp disease, not the least of which is a crack that has transected the pulp chamber or root canals. Other possible reasons for pulp injury include previous deep filling(s), or over-preparation of the tooth for the crown by your dentist.

By and large, if it is a crack that has breached the pulp, that would render the tooth unsalvageable, because such a crack would extend to a point well below the level of the bone. Neither placement of a crown nor implementation of a root canal treatment will save such a tooth. Therefore, your next task will be to have the tooth assessed for the cause for its pulpitis, and whether a crack still exists. This assessment may require removal of the crown, although if it comes to that, it should be removed by cutting rather than tapping, for the reason I indicated above.

You should consult with an endodontist (root canal specialist) for this purpose. The training and intuitive skills of this type of clinician will be able to apprehend the subtleties of your case that might otherwise evade the notice of the general practitioner. You can find contact information for an endodontist near you by consulting the online directory of the American Association of Endodontists.

Hope this helps...

Mr. Carr; I hope either I or Dr. Bornfeld were able to assist you in understanding the problem with your cracked tooth, since Dr. Bornfeld basically reiterated facts that I completely answered your question with. If we can be of more assistance please let us know. Dr. Rowe