Hello, Karen. I am not trying to put words in Brian's mouth at all, but I think I can answer your question. When I learned I had to have extractions just one year post treatment end, I did a lot of research. There is no mention I found of any 2-year waiting period. The important thing is the 20 hyperbaric treatments prior to extraction, which causes the growth of new capilaries in the radiated bone. This will, if all goes right, allow the extraction wounds to heal. 10 more treatments are given right after the surgery for the same reason. People with more money than brains take these treatments to regain youth and beauty. I, however, have noticed no difference (grin).