JamesSmith,

The disinfectants used during the rc procedure should not have entered the jaw bone during the procedure unless the tooth was already perforated (possibly fractured) and/or she perforated the tooth.

A post put into a root canaled tooth actually further weakens the integrity of the tooth, pre disposes it to fracture and contributes to additional inflammation. It's like driving a nail into a splinter of wood and then using that piece of wood as a hammer. The nail is the post.. the wood is the tooth... and the hammer is the chewing forces between the upper and lower teeth. Dentists who put posts in rc teeth do so because:

1) There is an inadequate amount of tooth structure to put a crown on the tooth so they use the post as a replacement for the missing area of tooth.
2) Some dentists think all rc teeth should have posts just because the tooth is fragile and the post will give it some support. See my #1 comment.
3) Some do so for the $$.

A crown is put on a weakened or fragile tooth more or less to act as a hard shell for chewing. Crowns are also put on for esthetics or when the tooth is unable to be restored properly with a filling material. Crowns do not strengthen the tooth, they just kind of hold it together for chewing purposes.

I think the reason your dentist prescribed antibiotics may be because she is concerned about the contamination that possibly occurred during the rc procedure (which has not clearly been established and if it did occur, antibiotics would not make any long term positive difference) .... or she is suspicious of infection .... or she knows there's a lot of inflammation in the tooth and ligament and she's hoping (???) that the antibiotic calms it down just long enough to do the post and crown.

Most conventional dentists are going to side with your dentist because this is basically how they practice too. You could consult with an oral surgeon (although he would most likely be of similar thinking) about the present status of the surrounding bone of this tooth...a periapical xray and possibly a panoramic xray might be helpful. But they are only 2 Dimensional so there could be something happening that is not able to be picked up on them.

The bottom line here is this.... ALL root canaled teeth are unhealthy. Your symptoms are not uncommon and therefore are often regarded as "normal" meaning "typical". The lower tooth may be biting too hard against the upper one causing the ligament around the lower tooth to be inflamed. Taking these two teeth out of occlusion, meaning drilling away minute amounts of either tooth so they hit against each other more gently does not alter the health status of the upper rc tooth. It would however reduce the inflammation in the ligament of the lower tooth. BTW.... what is the health of that lower tooth? Is it decayed, filled or crowned?

Bryanna