Prosthetics
Fixed Prosthetics
Crowns
Just like a queen’s crown is a specialized “hat” that fits over her head, a dental crown is a protective “cap” that fits over a tooth. Once cemented in place, crowns fully cover the tooth down to the gum line. In most situations a crown’s purpose is to protect the tooth from breakage, when little natural tooth structure remains; for instance, when much of the tooth structure has been lost due to decay or when a large portion of the tooth has broken off. Another common use for a crown is when a tooth has sustained a crack, but has not yet broken; in this instance, the crown protects the tooth from further damage by creating a “shield” from chewing forces. Crowns can also be used to restore a tooth’s natural size, shape, color, and function if teeth have been excessive worn, broken or decayed. These tooth-shaped “caps” are placed over a tooth. These covers restore the tooth’s shape, size and strength, while also improving the cosmetic appearance.
As a general rule of thumb, a filling is used to restore lost tooth structure when more than 50% of the natural tooth structure remains, while a crown is used to restore a tooth when less than 50% of the natural tooth structure remains.
Bridges
Dental bridges are put in place to bridge the gap between one or more missing teeth. The bridge is created by using one or more teeth on either side of the gap as support teeth (called abutments) to suspend one or more replacement teeth in the gap area (called pontics). Therefore, if we were to compare a dental bridge to a road bridge, the “pontics” would be like the “deck” of the bridge, while the “abutments” would be like the concrete piers on the land at either end of the bridge that the deck rests on putting 2 crowns on the teeth on each side of the gap (abutment teeth). Then a false tooth or teeth is placed in between. Bridges are technically refered to as “fixed partial dentures” but commonly referred to as “bridges”.
Bridges are hellpful because they restore dental function (ability to chew properly) and prevent the potentially damaging effects of teeth shifting or drifting around a missing tooth, as well as restoring the patient’s smile.
Implants
If a patient has lost one or more teeth, dental implants are often used to facilitate the replacement of missing teeth. Similar to natural tooth roots in size and shape, impalnts are made of a specialized type of metal alloy that is biocompatible (not rejected by the body). They provide a strong foundation for fixed (non-removable) or removable replacement teeth such as single crowns, bridges, or various types of dentures, which can greatly impoove dental function and attractiveness.
Removable Prosthetics
Complete Dentures
Complete dentures are a prosthetic device used to replace a full set of either upper or lower teeth. They are made of specialized plastics that mimic the natural look of both teeth and gum tissue. Dentures rely on a person’s gum and bone for support and retention, and are easily removed for daily cleaning or the occasional repair. Because dentures rest on the gums and underlying bone, which slowly changes in shape as we age, their bases require occasional rejuvenation (relining) so they continue to fit properly. When the teeth become worn, or perhaps when the patient desires a new look, the dentures may be remade with newer teeth.
Removable Partial Dentures
Usually referred to as “partial dentures,” removable partial dentures replace one or more missing teeth, use the remaining teeth on the dental arch for support and stability, and can be taken in and out of the mouth. They differ from “fixed partial” dentures because the patient can remove the dentures, as opposed to having them permanently cemented (fixed) to natural teeth.
Removable partial dentures usually have a metal base, referred to as a framework, which hold the plastic teeth. The framework has specialized parts that hold the appliance in place. For most people, this type of partial denture is a less desirable option for replacing missing teeth than a fixed partial denture, because removable partial dentures can move and therefore are less comfortable during chewing.
Immediate Dentures
Immediate dentures are any removable device, either complete or partial, which is provided for the patient at the same appointment in which one or more teeth are being extracted in association with that denture.
Conventional Dentures
Conventional dentures are any type of denture, either complete or partial, which is provided for the patient following the extraction of one or more teeth, once the healing process is complete.
Implant Supported Dentures
Implants are often used to stablize an existing denture that is loose and uncomfortable. Implant-supported dentures are full or partial dentures that attach to dental implants, making the dentures much more secure than when the conventional methods of resting the dentures on the natural teeth and/or gum tissue are used.
A complete implant-supported denture uses a minimum of two implants, and occationally as many as six to eight implants, depending on many factors, including the desired degree of denture sability, as well as limitaions on bone quality and quantity. In addition, Dr. McRory considers multiple factors when deciding whether a non-removable or removable implant-supported denture is best for each patient.