When a tooth is significantly damaged, decayed, or missing, it compromises both function and appearance. Restorative dentistry uses fixed solutions like dental crowns and dental bridges to repair these issues. These custom-made appliances reinforce existing teeth or replace lost ones, ensuring proper biting mechanics.
Understanding Dental Crowns
A dental crown is a tooth-shaped cap permanently cemented over a single, damaged tooth. It completely encases the visible portion of the tooth above the gum line. The purpose of this restoration is to restore the tooth’s original shape, size, strength, and appearance.
Crowns are recommended when a tooth has substantial structural loss that a standard filling cannot fix. This often occurs after a root canal procedure, which can leave the tooth structure weakened. The crown provides necessary support to prevent fracturing under chewing pressure and is also used to cover severely discolored or worn-down teeth.
Understanding Dental Bridges
A dental bridge is a fixed prosthetic device used to replace one or more missing teeth by bridging the gap. This restoration is typically composed of three or more units fused together. Replacing missing teeth is important to prevent adjacent teeth from shifting into the empty space, which can lead to bite problems.
The structure of a traditional bridge includes a replacement tooth, known as a pontic, which fills the void. This pontic is anchored by crowns, called abutments, that are placed over the natural teeth on either side of the gap. This design ensures the restoration remains stable and can withstand normal chewing forces.
Common Materials Used in Construction
The material chosen for crowns and bridges depends on the required strength and aesthetic demands based on the tooth’s location. All-metal alloys, such as gold or base metals, offer exceptional durability and require minimal removal of natural tooth structure, making them ideal for less visible molars.
Porcelain-Fused-to-Metal (PFM) restorations combine a strong metal substructure with a tooth-colored porcelain layer, balancing strength and acceptable aesthetics. These ceramic options eliminate the risk of a dark line appearing at the gumline, a potential issue with PFM crowns over time.
For visible areas, all-ceramic materials, like lithium disilicate, are preferred for their superior translucency and ability to mimic natural tooth enamel. Zirconia, a highly durable ceramic oxide, is popular for its strength, allowing it to be used successfully in both the high-stress back of the mouth and the aesthetically sensitive front.
The Placement Procedure
The process for receiving a crown or bridge requires two appointments spaced a few weeks apart. During the initial visit, the dentist prepares the tooth or teeth by carefully shaping them. This involves removing enamel to create room for the final restoration and ensuring the structure has a slight taper for proper seating.
After preparation, an impression of the teeth is taken, using either a putty material or a digital scanner. This impression is sent to a dental laboratory, where technicians fabricate the permanent restoration. Before the patient leaves, a temporary crown or bridge, usually made of acrylic resin, is cemented onto the prepared teeth to protect them and maintain function.
The second appointment involves removing the temporary restoration and checking the permanent crown or bridge for precise fit, color match, and comfort in the bite. Once adjustments are complete and approved, the restoration is permanently bonded to the underlying tooth structure using strong dental cement.