Tooth Abscess ?

I had a crown done about 6 weeks ago on my upper left back molar. While I had the temporary crown, everything seemed fine - it was as if nothing happened.  But after receiving the permanent crown, I began having sensitivity to hot and cold. It really wasn't that bad, so I didn't think much of it. But about 2 weeks after getting the permanent crown, my gum (cheek side) started to hurt (slight throbbing) and became a little inflamed and pulled back. When I massaged the gum with my finger, I got a really foul taste from the gum. So I went to the dentist. He examined the gum and the crown/tooth joint and didn't see anything that looked bad. When he massaged the gum, he didn't see anything, but I still got a slightly foul taste (but not nearly as strong). He then did a percussion test, tapping firmly on all surfaces of the tooth, and I had no pain. So he recommended using Peroxyl to help the gum heal, and just watching to see if the tooth got worse. Well, the gum healed and the foul taste disappeared. No more throbbing.  But the sensitivity to hot and cold has steadily worsened. Now hot or cold food or fluids causes a fair amount of discomfort. And now when I chew anything remotely firm, even bubble gum, the pressure from chewing is uncomfortable, almost painful. And the foul taste is back, though not as potent as originally.  So I'm going back in a week, but I hate waiting. Do you think this is a definite sign of a tooth abscess due to the trauma of the crown? When I called about the appointment, they were already talking about the possibility of being referred to an endodontist for a potential root canal. Is this my only option? Can I not just kill off the infection with antibiotics?  I broke the bank on the crown (no dental insurance), and I simply cannot afford another expensive procedure. If that's the only option to keep the tooth, then I may have to opt for extracting it (and keeping my $1100 crown of course). Has anyone had a similar experience or can offer any advice? Thanks in advance, Jason.

[scottma]

Thermal sensitivity  and discomfortable biting are probably associated with occlusal interference. Occlusal adjustment can generally eliminate the symptoms. Gum abscess may result from periodontal or periapical infection. Seeing a periodontist to evaluate periodontal condition is advised.