Can i smoke/drink alcohol after part of filling/tooth falling out from a (maybe 6 year old) root canal tooth? blackish crater about half cm deep in middle of tooth (no blood or pain)?

It is not contraindicated but you should see your dentist as soon as possible. Good luck.

The tooth should be examined for decay and resealed immediately.Smoking and/or alcohol abuse will not affect the tooth, but may have you on a path to severe medical problems. See your Dentist about restoring the tooth, which is less expensive than loosing nit an having to pay for a replacement. Talk to your Physician about dealing with your life threatening addictions.