Dental prosthetics is a specialized area of restorative dentistry focused on replacing or restoring damaged or missing teeth to improve function, comfort, and appearance. Fixed prosthodontics is a distinct discipline recognized by the American Dental Association (ADA). It provides durable, long-term solutions that are permanently bonded or cemented into the mouth. The defining characteristic of these restorations is their permanence, meaning the patient cannot remove them for daily cleaning or maintenance.
The Definition of Fixed Prosthodontics
Fixed prosthodontics involves the design, manufacture, and placement of custom-made restorations securely attached to existing natural teeth or dental implants. Unlike removable prostheses, such as dentures, these devices are cemented into place by a dental professional and remain in the mouth indefinitely. The primary goal is to restore the integrity of individual teeth and the dental arch, addressing both function and appearance.
This restorative approach is indicated when a tooth has suffered extensive damage from decay, fracture, or wear too substantial for a simple filling. Fixed devices permanently replace missing tooth structure or bridge gaps, helping to re-establish proper biting alignment and prevent the shifting of adjacent teeth. The stability provided by a securely fixed restoration offers superior function that closely mimics that of natural teeth. This ensures the device will not become loose or dislodged during eating or speaking.
Specific Types of Fixed Restorations
Fixed prosthodontics encompasses several different types of devices, each tailored to address a specific restorative need. The most common fixed device is the dental crown, a full-coverage restoration that completely caps a compromised tooth above the gum line. Crowns restore a tooth’s shape, size, strength, and appearance, often following a root canal or when a large portion of the tooth is lost. They protect a weakened tooth from fracturing under chewing forces.
When one or more teeth are missing in a row, a dental bridge is used to span the gap. This restoration consists of an artificial tooth, known as a pontic, fused between two or more crowns (abutments) cemented onto adjacent natural teeth or implants. The bridge locks the teeth on either side together, preventing them from drifting into the open space.
For teeth with moderate damage but enough healthy structure, dentists may use inlays and onlays as more conservative options than a full crown. An inlay is a custom-fabricated restoration that fits within the cusps (peaks) of the chewing surface. An onlay is similar but extends to cover one or more cusps, providing reinforcement against biting forces.
Veneers represent another category of fixed restoration, used primarily for cosmetic purposes on the front teeth. These are thin, custom-made shells of tooth-colored material permanently bonded to the tooth’s front surface. Veneers correct aesthetic issues like discoloration, minor misalignment, chips, or abnormal tooth shape.
The Multi-Step Process of Placement
The placement of a fixed restoration typically involves a multi-appointment process to ensure the custom device is precisely fabricated and fitted. The initial appointment focuses on preparing the supporting tooth or teeth. This preparation involves carefully reducing and shaping the natural tooth structure to create space for the prosthetic material without appearing bulky.
After the preparation is complete, the dentist takes a highly accurate impression (physical mold or digital scan) of the prepared area and surrounding teeth. This impression is sent to a dental laboratory, where technicians custom-fabricate the final restoration. A temporary restoration is placed over the prepared tooth to protect it from sensitivity and maintain proper tooth position while the final device is being made.
The laboratory phase can take several weeks while technicians craft the prosthesis using materials specified by the dentist. Once the final restoration returns, the patient returns for the final placement appointment. The temporary is removed, and the permanent device is checked for proper fit, bite alignment, and aesthetic appearance. The dentist then uses a strong dental cement or bonding agent to permanently affix the restoration.
Materials, Maintenance, and Expected Lifespan
Fixed prosthodontics can be fabricated from a variety of materials, with the choice depending on required strength, location, and aesthetic considerations. All-ceramic materials, such as porcelain and zirconia, are favored for closely mimicking the translucent appearance of natural tooth enamel. Zirconia is a ceramic oxide known for its exceptional strength, making it suitable for restorations in high-stress areas like the back teeth.
Traditional metal alloys, often layered with porcelain to improve appearance, are used when maximum durability is required. The long-term success of any fixed prosthesis relies heavily on meticulous daily maintenance, just like natural teeth. This includes brushing twice daily and flossing around the margins of the restoration to prevent plaque accumulation and secondary decay.
Patients with bridges must use specialized tools, such as floss threaders or interdental brushes, to clean the area underneath the artificial tooth (pontic). Fixed restorations have an expected lifespan, often ranging between 10 and 15 years, though many last longer with proper care and regular professional check-ups. Longevity depends on the material, the patient’s oral hygiene habits, and the forces of their bite.