At my last dental exam, dentist said gums were getting to be an issue. Try a water pic. Did it for six months while learning not to spray the mirror or myself so much. Got a "good gums" during my pre-radiation exam. Start off low pressure and may want to talk to doc before considering it.
P.S. talked to a guy just finishing rad/Chem. He said the salt/baking soda gargle was effective for throat care. Don't see why it wouldn't help with tooth care as well.
I'm planning to use the pic during my treatment and may consider dissolving saltbaking soda in the pic water. I'll see what doc says. Good luck.

My dentist always checks around my neck and underneath my tongue, looking for lumps or swelling. Unfortunately, dentists and other health care providers can only act on their own training and experience, the same as all of us. They may hesitate to refer a patient to a specialist unless they are really sure its outside their own expertise. When I went to see my GP about the lump on my neck, he put me on antibiotics for 10 days instead of immediately referring me to a specialist. I had to call his office twice to remind him that he was supposed to make the call if the lump had not gone away after the antibiotic treatment. By then the lump had grown from the size of a pea to the size of a walnut. A specialist generally won't see a patient unless they have a referral from another doctor. Those referrals can be hard to get. It may be an insurance issue, I don't know.