A dental crown is a custom-made, tooth-shaped cap designed to fit entirely over a natural tooth that has been damaged or compromised. This restoration completely covers the tooth, extending from the chewing surface down to the gum line. The main goal of placing a crown is to restore the tooth’s original shape, size, and strength while simultaneously improving its appearance. A crown provides a robust, long-term solution for maintaining the health and function of the natural tooth structure underneath.
Primary Reasons Crowns Are Necessary
The decision to place a dental crown is driven by the need to protect a tooth whose structural integrity has been compromised. One common reason is to safeguard a tooth that has undergone a root canal procedure. After the inner pulp is removed, the tooth often becomes brittle and susceptible to fracture, making the crown an essential protective measure.
A crown is also indicated when a tooth has extensive damage from decay or a filling that is too large for the remaining natural tooth structure to support. If a large filling has failed or too much tooth material was removed, the surrounding walls become weak and prone to breaking. The crown holds these weakened parts together, preventing the tooth from splitting and potentially requiring extraction.
Teeth that are severely worn down, chipped, or fractured also require a crown to restore their function and form. Chronic grinding (bruxism) can shorten and flatten teeth, and a crown rebuilds the necessary tooth length and contour. For a fractured tooth, the crown acts as a stabilizing splint, preventing the crack from worsening and reaching the nerve.
Crowns serve important roles in prosthetic dentistry, often acting as anchors. They are used to hold a dental bridge in place, covering adjacent natural teeth to support the replacement tooth. Furthermore, a crown forms the visible, functional part of a dental implant, attaching to the artificial root placed in the jawbone. Crowns can also be used for cosmetic modification, covering severely discolored or poorly shaped teeth.
Structural Role: Protecting and Restoring Tooth Function
Once cemented onto the prepared tooth, the crown acts as a protective shield, absorbing the heavy forces of biting and chewing. By completely encircling the remaining tooth structure, the crown distributes the load evenly across the surface. This prevents the underlying damaged or weakened tooth from fracturing under pressure, which is particularly important for back teeth.
Beyond protection, the crown restores the tooth’s proper shape and size, which is necessary for correct alignment of the bite, or occlusion. A damaged or worn tooth can disrupt the balanced contact between the upper and lower jaws, leading to discomfort or excessive wear on other teeth. The custom-designed crown ensures the tooth meets its opposing counterpart at the correct angle and height, restoring comfortable chewing function.
Crowns are fabricated from various materials, and the choice influences both strength and appearance. All-metal crowns, often made of gold alloy, offer superior strength and durability for molars. Porcelain-fused-to-metal (PFM) crowns provide a balance of strength from the metal substructure and a natural appearance from the porcelain overlay. All-ceramic or all-porcelain crowns, frequently made from materials like zirconia, offer the best aesthetic match, making them the preferred choice for visible front teeth.
The Process of Getting a Dental Crown
The procedure for receiving a dental crown typically requires two separate appointments, unless the dentist uses same-day CAD/CAM technology. During the initial visit, the tooth is prepared by reshaping and reducing the outer structure to create space for the crown. The dentist removes a precise amount of enamel to ensure the final cap fits snugly without appearing bulky or interfering with the bite.
After preparation, an accurate impression or digital scan of the reshaped tooth is taken. This is sent to a dental laboratory, where technicians custom-fabricate the permanent crown to match the contours and shade of the surrounding teeth. Before the patient leaves, a temporary crown is placed over the prepared tooth to protect it and maintain the space while the permanent restoration is being made.
The second appointment occurs when the lab-fabricated crown is ready, usually one to two weeks later. The temporary crown is removed, and the permanent crown is test-fitted to confirm the color, shape, and bite alignment are perfect. Once all adjustments are complete and the fit is verified, the dentist permanently bonds the new crown to the tooth using a strong dental cement, finalizing the restoration.