Complete dentures come in many shapes, sizes, and fits. How well full dentures will fit will depend on the current shape of the mouth, the amount of bone remaining to support that denture, and the functional requirements of the said denture.
A regular denture sits on the gums and underlying bone that supports it. Over time, bone levels and accompanying gum levels recede, leading to loose dentures and an increasing need for denture relining / refitting.
Dental implant supported dentures, on the other hand offer a retention that performs closer to your natural teeth than a denture that can slide around on top of your gums. Where a traditional upper denture may fit and function well due to utilizing the palate / roof of the mouth for support and suction effect, the lower jaw is not afforded that luxury.
Dental implants placed on the lower jar, commonly towards the front where there is more bone, allows permanent “roots” to be anchored in place. When healing is complete, one of two different “gripping” platforms may be used to connect to the dental implants. One platform is the use of a bar connector, whereas another is the use of “ball hitch” type connectors. Whichever platform is chosen is based off of what is best matched for the needs of a particular situation, the internal aspect of the involved dentures are modified so they can now be “mated” to the connector platform. These modifications are usually plastic clips or plastic cups that match the “bar” or “ball hitch”. There are plastic fittings that are modified to fit on the underside of the denture do much of the work that handles much of the “grip” and torque, and a result, are a “wearable” item, much like tires and gaskets are and will need to be checked once every six months to a year and should be evaluated for your specific situation.
Implant supported dentures are definitely a viable option today and should need considered if you have challenges with chewing certain foods or suffer from a denture that is always loose or battling denture based sore spots on the gums.