Bone graft, immediate denture
I highly recommend bone grafting after extraction to preserve as much of the bone as possible as part of a denture or a implant supported prosthesis. Without bone grafting high percentage of the bone will resorb due to the space created in the extraction site by removing the root of the tooth.
Grafting at time of tooth extraction preserves bone width
40-60% of bone volume is lost within the first year of a tooth extracted, but grafted sites prevent that. A denture will result in more rapid bone volume loss than simply extracting, so every little helps. If implants are planned in the future, this may be a significant savings of both time and money. If implants AREN'T planned, this still preserves bone needed for denture stability.