Dentures: complete and Partial
metal base vs. acrylic
A denture is an appliance that is inserted in the mouth, replaces natural teeth and provides support for the cheeks and lips.
Most dentures are made from only acrylic or combination of metal and acrylic.
Even though acrylic is more esthetic, this type of denture is less functional. An acrylic denture is thicker (acrylic is not strong as metal) and this denture conveys forces horizontally on the teeth, which is not natural, causing abutment teeth to start loosening over time. Horizontal forces will also cause bone resorption and bone “sinking” which will make teeth more out of the bone, sensitive to hot and cold due to gum and bone recession, and in long run, increase tooth mobility.
On the other hand, metal base acrylic dentures are thinner and smaller (metal is stronger) and they convey masticatory forces — vertically, along the long axis of the tooth, which is natural and they have clasps that rests on the occlusal surface not allowing the denture to “sink down” lowering the level of the bone. Their retention and stability are much stronger due to clasp/ est system.
- A complete denture is made after all teeth have been extracted and the tissues (gums) have healed.
- A partial denture replaces one or more missing teeth.
- An immediate denture is fabricated and inserted immediately after the teeth are extracted and the tissues are allowed to heal under the denture. They need replacement after 6 months. The reason is because the tissue undergoes remodeling and resorption after extraction.
- An upper denture covers the palate (roof of the mouth).
- A lower denture is shaped like a horseshoe to leave room for the tongue.
The teeth are made of plastic, porcelain or a combination of both. Dentures can be fabricated to fit over endodontically-treated teeth and a complete denture can be attached to dental implants to allow for a more secure fit of the appliance — overdenture. Implants significantly increases retention and stability of the denture, so the patient has a feeling that he/she is chewing on their own teeth.
Over a normal course of time, dentures will wear and need to be replaced or relined in order to keep the jaw alignment normal. The alignment will slowly change as the bone and gum ridges recede or shrink due to the extraction of the teeth.
Regular dental examinations are still important for the denture wearer so that the oral tissues can be checked for disease or change. Remember, those gums are exposed to lots of pressure during mastication!