Experiencing speech problems due to a new set of dentures is very common. The problem will usually dissipate once you have gotten used to your new dental plates. The temporary speech problems are caused by the sensation of fullness from the new dentures in your mouth and the excess saliva that it produces. With some practice in forming your words, your speech should be back to normal within a few weeks.
Dentures are a foreign object in your mouth and will cause your mouth to produce extra saliva. This excess saliva can be very difficult to keep contained in your mouth while speaking. This will cause you to mumble as you speak or cause an unintended lisp.
Gargle and Mumbling
The saliva can also act as a lubricant, causing your dentures to slip on occasion. This can cause a gargle-type of speech and possibly some mumbling as well.
New dentures can place your front teeth in a different position than your natural teeth were. It may take some time to find this new position with your tongue when forming words. For this reason a lisping or whistling sound may appear while you are speaking.
Dentures can make your mouth feel full and speech can sound as if you are speaking with a mouth full of food for that reason. This is a sensation that can occur when you first get your dentures but will wear off as you get used to them.
For the extra saliva in your mouth produced by the dentures, it can be very helpful to such on some hard candy or lozenges. This allows you to swallow the saliva naturally and helps with clearing up the speech problems.
Your gums are going to take time to form to your new dentures and even then they still may tend to slip causing a problem with your speech. Using denture adhesive will keep them in place and allow you to speak without obstruction.
In time your dentures will feel natural to you and your speech will return to normal. You can practice your speech by reading aloud and repeat words that you frequently have trouble pronouncing.