Access to the root on the front teeth can be done from the tongue side, so there should be no damage to the veneers. After the root canal is completed, a bonded filling to fill in this hole is all that is usually needed.
No Problem! On a typical veneer case if a tooth needs a root canal, a small access hole is made on the tongue side of the tooth. The root canal is then completed and a small filling is placed to seal this hole. The veneer remains intact and looking great. Good Luck!