My suggestion is for you to have a full exam and a CT scan to assess the reasons for the dentures cutting into your gums. It is very likely that you are losing the bone underlying the dentures, and therefore the edges are being force further into your gums because of the lack of support. I can take this CT scan in the office, as well as complete an exam if you are interested. Sometimes, implants can help with this type of problem. I hope that helps. Dr. Steve Aeschliman, Periodontist.
It all depends on how long you have your dentures. As your gum shrinks, you need to reline your dentures. If this did not solve the problem, the oral cavity needs to be checked for any type of abnormalities.