Dentures
Why do I keep getting mouth ulcers under my dentures?
30 October 2026 · The Dentist, Al Qusais, Dubai
The short answer
Recurring ulcers under dentures almost always come from a pressure point where the denture base rubs against gum tissue, usually because the fit has changed as your gums and jawbone reshape over time. Minor sores from a new denture settling in are normal for the first week or two, but ulcers that keep returning in the same spot mean the denture needs adjusting, not that your mouth is simply prone to ulcers. If a sore hasn't healed within two to three weeks even after adjustment, it needs to be checked properly rather than treated as a denture problem.
What's actually rubbing against your gum
A denture sits on soft tissue over bone, and both of those change shape over months and years. Once a tooth is lost, the jawbone underneath starts to resorb, slowly and unevenly. That means a denture made a year or two ago may no longer match the exact contours of your gums today. Even a very slight mismatch creates a high spot, and every time you bite or talk, that spot takes repeated pressure until the tissue breaks down and forms an ulcer.
It's also common for one side to wear differently from the other if your bite is uneven or if you chew mostly on one side out of habit. New dentures cause a different version of the same problem: the acrylic hasn't been shaped around your specific gum contours yet, so a small adjustment visit in the first week or two is completely normal and expected, not a sign anything went wrong.
Why it keeps coming back in the same place
If the ulcer shows up in the same spot every time, that's actually useful information: it tells your dentist exactly where the denture needs easing. Patients sometimes try to manage this themselves by taking the denture out for a few days, letting the ulcer heal, then putting it straight back in. The ulcer returns almost immediately because the pressure point was never actually corrected, only avoided for a while.
Poor hygiene makes this worse. Plaque and food debris trapped under an ill-fitting denture irritate the tissue further and can lead to a fungal condition called denture stomatitis, which causes redness and soreness across a wider area rather than one sharp ulcer. Cleaning the denture properly every day and taking it out overnight to let the gum tissue rest and breathe reduces this significantly, but it won't fix a genuine fit problem on its own.
When an ulcer needs more than an adjustment
Most denture-related ulcers settle within a few days of the denture being eased or relined by a dentist. What shouldn't happen is an ulcer that lingers for more than two to three weeks, keeps growing, feels hard at the edges, or doesn't hurt the way a normal ulcer would. Those features need a proper look, sometimes including a small biopsy, because persistent non-healing sores in the mouth are one of the things dentists specifically screen for and shouldn't be assumed to be "just the denture" without checking.
If you're dealing with recurring ulcers, the honest first step is to have the denture assessed rather than guessing at home remedies. At The Dentist in Al Qusais, Dr. Faris Alkhanafseh and Dr. Mohammad Nour can check the fit, ease the pressure points causing the irritation, and look at the sore itself to confirm it's healing as expected. New patients get a free first checkup, so there's no cost barrier to getting it looked at properly, and if a reline or new denture is genuinely needed, you'll get a written quote before anything is agreed. You can book through WhatsApp or online at thedentist.ae/book.
This article is general information, not a diagnosis. If you are in Dubai, the free first checkup at our Al Qusais clinic is the fastest way to get an answer about your own teeth.