numb mental nerve AND infection under tooth - do nothing??

[Mars74201mum]

I would be very grateful if there are any dentists out there who could give me some advice as I'm not sure what steps to take next. Do nothing? Hurry and have root canal?

I went to the dentist on Friday for a check up and also because I've had a mild toothache for about a week (say 2 out of 10 in terms of pain). The dentist did a scan and the scan showed infection at the base of one of my right lower back teeth. He said there was no sign of decay, the infection probably got in via some other route (maybe a hairline crack for example).

But because he was surprised I wasn't in proper pain and can eat on that side and have no problem with hot drinks etc, he did a test with something very cold on cotton wool on my teeth and that showed that the nerve on my right side that goes all the way along the rhs under my teeth was numb. The other side was fine.

He said it was probably nothing but always good to get a second opinion so he'd refer me to hospital, that would probably take a month or so.

Then he turned his attention back to my tooth and explained that it would need rootcanal and that he could do it soon or I could leave it till a later date, up to me. He said pain might set in immediately or not for say 5 years, everyone is different.

My question is really - if I'm not in pain (because the nerve is numb) is it ok just to ignore the infection that is there? Is there any reason to have rootcanal at all if I can't really feel the pain? If I leave it will it spread to other teeth?

My dentist muttered something about giving me antibiotics but didn't - would that be a good idea?

I'm left wondering if I should tell my doctor about this referral to hospital, in case the dentist doesn't remember to refer me (he's not my regular dentist).

Sorry to ask, I would be grateful if any dentists could advise.

Thank you