Ken's wife,
I'm sorry to hear about your husbands situation.
I have always advocated second and even third opinions due to the fact that every professional has not had the same level of experience and training.
I am pleased that his new dentist put off treatment with a new bridge due to the fact that
she determined that periodontal disease was present, "...she said that he has gum disease and saw some pus and that no way would she give him a bridge until this was cleared up."
I am, however, unclear from your post as to the method of treatment that she proposes to use to eliminate and/or control the gum disease. There is no fluoride product on the market that I am aware of that will contol/treat/eliminate periodontal disease. I am also not aware of any appliance that a person can wear nighttime and/or daytime that will treat gum disease.
I am a big advocate of fluoride for cancer treatment patients who experience tooth deterioration and/or dry mouth and as well believe in tooth preservation.
Pus...pus means infection/abcess is present in the gums or mouth or around the teeth it must be treated by eliminating the source of the infection. There is no oral rinse or fluoride application that can cure this problem.
I would suggest that you ask that your husband be referred to a periodontist to make sure that his teeth and supporting structures are all free from disease and in a sound state of health and as well to find and treat the source of the "pus" before anything else is done.
Cheers,
Mike