Of course it affects our teeth. My Dentist - who I LOVE dearly -

took a long while to explain. The jaw bone requires teeth. When we eat, yawn, talk, smile, giggle …….. although we aren't aware the teeth react against the jaw bone which keeps the jaw line healthy. Think brisk walking to stave off osteoporosis, well the jaw line requires action.
So: if 1 loses a tooth/teeth the gap won't have impact onto the jaw. Which will shrink in that area = other teeth becoming loose. So saving as much of each tooth is important. I have had both root canal therapy, a crown that wasn't fitted correctly (long story short) and implants.
Unless 1 has an accident implants are considered cosmetic surgery, I believe that Crowns are also. So I paid out several £K for implants. One tooth required removal prior to 'work' well, it was well set into the jaw line and twisted - the root ran under other teeth

and the effects of the LA wore off during extraction

. I had 3 Surgeons at it and did think it was going to be a 'blue light' issue to Hospital for full GA but eventually !
Now I have 3 implants which require a lot of care with cleaning around the gaps between the other teeth. The whole process takes from 8-9 months; DO NOT allow a dentist to even suggest removal of teeth and replacement by implants on the same day. It needs a qualified implant surgeon who is able to judge bone density and who has time and experience.
As for the LA making you woozy, are you on any medication? The dentist was unable to top up the LA (see above) due to my medication. It is worth telling the Dentist B4 you undergo further treatment! I had severe pain following the last root canal even though the nerve was removed, which is why I opted for implants.