Unable to numb tooth to replace crown

[tabhollywood]

Both my husband and I are dental phobics and have recently starting addressing this with visits to a very calming Dentist after 10 + years without regular dental treatment.
My husband has a broken crown on his front tooth which needs replacing. The problem is that when she came to numb the area she was unable to achieve numbness to carry out the work despite numerous injections and 2 different types of anethesia. She did attempt to start prepping for a new crown but he was unable to stand the pain. She couldn't understand why he wouldn't numb and decided to leave it to settle down for a few weeks before trying again.
The following day his lip was hugely swollen and numb and he saw a different dentist ( ours had a day off) who said the inside of lip and top of gum had ulcerated because of the injections and prescribed Amoxycillan to prevent infection and again stated it would settle down.
A week after completing the course he got it checked again, as although swelling had mostly gone a little numbness remains. The dentist did an xray mentioned that she couldn't see anything on it but that perhaps there was a slight infection in there and to take more antibiotics and wait a month for the tooth to settle before possible root filling and replacement of the crown. Unfortunatley he is unable to take these antibiotics ( Metronizle - can't spell it) due to previous stomach issues. So after yet another dental visit she advised to go without antibiotics and adopt a wait and watch type thing. With strict orders of any pain to go back in and get another antibiotic treatment.
Just a couple of questions on his behalf if you don't mind:
1, Could the inability to numb him be because of an undetected infection already in the tooth?
2, He smokes a lot of cannabis after work in the evenings to de stress - can that cause a increased tolerance to the anethesia injections?
3, Does it sound like standard advice to leave it to all calm down on its own before reattempting.

I desperatley want to get this sorted for him as he has come so far and would hate for anything to reignite that fear of getting him into the dentist chair again. The upside of all of this is that the frequency of dental visits has somewhat diminished his phobia and the fact that he has excellent teeth ( always a worry prior to examination I think he thought he'd need loads of work)

We are in the UK and have a NHS Dentist.

Apologies for the length of post

 

[Dr. Daniel]

1, Could the inability to numb him be because of an undetected infection already in the tooth?

An inflamed tooth is more difficult to achieve good anesthesia, but non the less it is possible and it's the dentist responsibility to achieve this.

2, He smokes a lot of cannabis after work in the evenings to de stress - can that cause a increased tolerance to the anethesia injections?

There is a grain of truth in it, both physiologically and psychologically speaking, but not to the extent that prevents good anesthesia.

3, Does it sound like standard advice to leave it to all calm down on its own before reattempting.

if a tooth is sensitive even anesthesia was effectively applied, it probably needs a root canal treatment. It is better not to wait with a root canal treatment the because in most cases the it means a real toothache (until the root is treated).

 

[tabhollywood]

Thanks very much - I'll get him to call and make an appointment for a root canal