It is happening to me.
Last night, my mom asked if it was from the cancer, chemo, or just from my genes/oral hygiene. I have a feeling its a combo of all of that.
But, can I express that I had daily chemo and lots of it...both IV and orally. During that time, I used a sponge or a baby toothbrush (no joke) and could not floss or use listerine. I only used Biotene when I could tolerate the taste (let's make that another topic for another day). The chemo's main goal was to kill off my blood production so my bone marrow would reset, so to speak. I would stop making platelets, hemoglobins, and especially we wanted my ANC to drop to as close to zero as possible. I really feel this played a big part in my dental issues today.
Now, I've never had braces. My teeth may not be straight, but they are good. Since I finished chemo, I had all four wisdom teeth removed, I've had a crack in a tooth that resulted in a filling "leak" and ended up with a crown, over 5 fillings, and now I'm dealing with major tooth sensitivity.
Could I be brushing too hard? Surely. I've now switched to Sensodyne toothpaste. The link below might help if anyone is dealing with sensitive teeth. A few of mine on the bottom have become sensitive to temperature and even pressure. Cold drinks especially send a jolt through my bottom teeth lately!