Why Immediate Dentures Require Modification
Complete dentures are when the dentures replace the entirety of your upper or lower dental arch (which is made up of all the teeth in your upper or lower jaw). There can be a sense of relief when you receive these dentures, which usually happens immediately after the final remaining teeth in a dental arch are lost, often after extraction by a dentist. In the weeks that follow, this sense of relief can be replaced with uncertainty. Your dentures are supposed to be immediate, so why do they rapidly feel as though they don't fit, perhaps even uncomfortably so?
Aesthetic and Functional
Your dentist doesn't want you to be without teeth for any period. This concern is both aesthetic and functional, meaning your dentist wants to spare you any embarrassment about your missing teeth, as well as giving you the ability to eat and speak naturally (which can be severely hampered by an entire missing dental arch). This is why dentures are generally inserted immediately after your final missing teeth have been extracted.
It's important to realise that immediate dentures offer an immediate solution, but will require modification in the coming weeks or months. Inflammation is to be expected when teeth are extracted, and the contours of your mouth will change, ever so slightly, as your gum tissues heal. It's for this reason that the way the dentures feel in your mouth (and how well they fit) will quickly change as your mouth heals. Not to worry, because it's not as though your dentist considers the job finished.
A Follow-up Appointment
Likely, your dentist will already have scheduled a follow-up appointment, and you just need to keep this appointment. It's not a standard checkup, and it serves a specific purpose, namely the modification of your denture base plate to ensure the best fit once all the soft tissue in your mouth has healed.
This modification is a very straightforward process, and your dentist will add a thin layer of resin to the base plate to reflect the finalised, post-healing contours of your mouth. Skipping this step is extremely unwise, otherwise, your dentures will continue to be ill-fitting and uncomfortable. In the years to come, additional relining will be required, as the contours of your mouth will continue to change, however slightly. This relining won't be a regular occurrence by any means, and should only be needed every five years or so.
Don't be concerned when your immediate dentures quickly begin to feel as they no longer fit. This is an entirely expected part of the process, and can easily be corrected. Contact a local dentist if you have more questions about dentures.