Anything CAN cause spread so it is good to be cautious. It's really up to you if you want to take the risk on something like that but it does sound pretty invasive. Have you looked into sedation dentistry? I did this when I needed a lot of dental work done this year and it worked out really well for me. There were no shots involved...it was all oral sedation with meds and such. Apparently I was technically conscious the entire time but have no memory of any of the work. You'd need to have someone with you though to drive you to and from the procedure though with that.

I needed a lot of dental work this year and I experienced spread from a lumbar sympathetic block a couple of years ago so I know I am prone to spread. I was very nervous and I won't let my dentist do any root canals. If the tooth needs to go then we just pull it. I spent a lot of money on bridge work...but feel a lot more comfortable with that vs doing any more invasive dental procedures.

Hope you are able to find a solution that works best for you. Take care and good luck!