A complete denture is used to replace teeth for either the upper or lower jaw or for both jaws, when all teeth in these areas are missing or need to be removed. Dentures are made as "false teeth" set into a pink acrylic material that serves as a base which covers the gums and bone where teeth are no longer present.
An upper denture has a base of the denture that covers the gums as well as the roof of the mouth. By covering more area in the mouth, a seal is made that allows the denture to adhere firmly in the mouth. Occasionally, there may be difficulty in obtaining a tight fit if insufficient bone structure is present to provide a proper seal, or if a patient struggles with a strong gag reflex where the denture is unable to cover the proper surface area.
A lower denture is made to cover only the gums and bone of the lower jaw. It is generally unable to provide a tight seal, since the tongue and cheek muscles tend to dislodge it and thus it has more potential for movement. It is best held in place by training the tongue and cheek muscles to maintain stability; thus more time is necessary to adjust to a lower denture than an upper. However it is possible to achieve great stability if the denture is seated on top of 2 or more implants, which allows the lower denture to "snap on" to the lower jaw.
An immediate denture is a type of denture that is made for prompt replacement of teeth on the day that teeth are removed. While these dentures can help to prevent having any time when you are without teeth, they have their own set of problems. They must be left in for the entire 24 hours after removal of teeth or the gums may swell upon removal and you may be unable to replace them again until the swelling subsides. Once the majority of the swelling does go away, these dentures will start to feel loose quite quickly. A series of relines may be necessary during this time of healing (over 6–12 months) and are generally completed in the office with a soft, removable reline material. Once healing is completed, a permanent reline or new set of dentures may need to fabricated.
Over the time a denture is worn, the pressure of the false teeth on the jaw bones causes the bone to resorb, or shrink away. As this happens your dentures may loosen and it may feel as though there is space between the denture and your gums. When this occurs, a reline of your dentures is necessary to ensure proper function and prevent sores on the gums. This reline is completed by taking an impression of your mouth inside your existing denture and sending it to the lab for addition of the pink acrylic to the inside of your denture. This procedure will take two visits to complete and may leave you without your denture for at least 24 hours. A proper reline should make your denture feel as though it fits much tighter.
A partial denture is used to replace multiple missing teeth in one or both jaws, as needed. They can be made as a temporary fix for a missing tooth while healing from the placement of an implant or can be made for permanent replacement of missing teeth.
A permanent partial is generally made with a metal base that retains the pink acrylic on it, as well as provides a more solid link for the teeth to the base of the denture. The metal base has arms that are fused with it that hook around the remaining teeth to ensure stability of the entire denture. Occasionally, special types of partials can be made that link into crowns on existing teeth to minimize the appearance of the metal arms around the teeth. The newest designs in partials are metal-free and utilize a flexible clear or pink acrylic base. While this partial may be more esthetic, there is less ability to adjust these dentures to fit tightly as they loosen and they can be difficult to repair.
A temporary partial denture can be made to replace teeth while waiting for something more permanent. It can be used as an immediate replacement, to be put in the mouth directly after removal of teeth. It is generally made of a pink acrylic base with false teeth placed into it. It works best when small metal clasps, or "arms", are placed to link onto remaining teeth to ensure stability. This type of partial is often called a "flipper", as you are able to flip it in and out of the mouth quite easily. Since there is only acrylic material present, and no metal for the base, it is more likely to break over time and therefore is not advised for long term use. Similar problems can occur with immediate partial dentures as described above with immediate complete dentures and regular visits may be required until healing is completed to ensure a proper fit so that damage is not done to the remaining teeth that are being used as a supportive base.
Partial dentures also require relines on occasion if space is noted between the base of the denture and the gums where teeth are missing. This process is described above for complete dentures. However, partial dentures often require adjustments to the clasps or arms that surround the adjacent teeth to reestablish a tight fit, after a denture has been taken in and out of the mouth many times and the clasps have loosened. It is not recommended that patients make these adjustments themselves, as the clasps can be fragile and may be broken off.
Partial dentures are highly recommended over complete dentures for the lower jaw due to the issues of fit and stability described previously. If there is any way to save some of the teeth for the lower jaw to allow for a partial rather than a full denture, it would be wise to consider this option.