The terms “dental crown” and “dental cap” are frequently used interchangeably by the public to describe the same dental restoration. While “cap” is a colloquial term, “crown” is the precise clinical name used by dentists. A dental crown is a tooth-shaped cover that completely encases the entire visible portion of a tooth above the gum line. This restoration restores the tooth’s shape, size, strength, and overall appearance.
Understanding the Dental Crown
A dentist recommends a crown for structural and functional reasons when a tooth is compromised beyond what a simple filling can repair. Crowns strengthen teeth severely weakened by extensive decay or fractures. The crown provides a protective shield, preventing the tooth from breaking apart under biting and chewing forces.
This restoration is useful for protecting a tooth that has undergone a root canal procedure, as such teeth can become brittle and susceptible to fracture. When a tooth has a very large filling, a crown is placed over it to hold the tooth together and support the remaining structure. Crowns also serve as the anchor for a dental bridge, securing the prosthetic teeth to the natural teeth on either side of a gap. They are also used to cover a dental implant post or to improve the cosmetic appearance of a misshapen or severely discolored tooth.
The Process of Receiving a Crown
The process of receiving a permanent crown typically involves two separate appointments, separated by about two weeks. The first appointment focuses on preparing the damaged tooth so the crown fits precisely without interfering with the bite. This preparation involves reshaping the tooth by removing a specific amount of the outer enamel and dentin. The exact amount removed depends on the type of material chosen for the final crown.
After shaping the tooth, the dentist takes an accurate impression of the prepared tooth and surrounding teeth, often using a digital intraoral scanner. This impression or digital file is sent to a professional dental laboratory, where skilled technicians custom-fabricate the permanent crown. Before the patient leaves, the dentist places a temporary crown over the prepared tooth to protect it from sensitivity and maintain the space.
The second appointment occurs once the lab-made crown has been delivered. The temporary crown is removed, and the dentist assesses the fit, shape, and color of the permanent crown to ensure it is comfortable and aesthetically pleasing. Minor adjustments to the crown’s shape or biting surface may be made during this time to achieve a perfect fit. Once confirmed, the crown is permanently bonded or cemented onto the tooth using a durable dental adhesive.
Types of Materials Used for Crowns
Dental crowns are constructed from several different materials, each offering a distinct balance of strength, appearance, and cost. All-metal crowns, often made from gold alloys or other base metals, offer the greatest strength and durability. They are the least likely to chip or break, require the least amount of natural tooth reduction, and are typically reserved for molars where biting forces are highest and aesthetics are less of a concern.
Porcelain-fused-to-metal (PFM) crowns represent a traditional compromise, combining a metal inner shell for structural strength with a porcelain outer layer for a tooth-colored appearance. While PFM crowns offer a balance of durability and acceptable aesthetics, they may sometimes show a dark metal line at the gum margin over time, and the porcelain layer can chip. The porcelain surface can cause slightly more wear on opposing natural teeth.
All-ceramic or all-porcelain crowns, which contain no metal, are chosen for their superior aesthetic qualities, as they mimic the translucency of natural tooth enamel. Modern materials like Zirconia and E-max have significantly advanced all-ceramic options, providing high strength suitable for both front and back teeth while maintaining excellent aesthetics. These newer ceramic crowns are often bonded to the tooth, which enhances the restoration’s overall strength.
Care and Longevity of Dental Crowns
With proper care, a dental crown can provide a long-lasting restoration, generally functioning well for an average of five to fifteen years or more. The crown’s lifespan is heavily influenced by the material used and the patient’s consistent oral hygiene habits. To maximize the crown’s durability, it is important to practice standard oral hygiene, including brushing at least twice daily with a fluoride toothpaste.
Daily flossing is particularly important around the crown’s margin, which is the area where the crown meets the gum line, as this area remains susceptible to decay and gum disease. Patients should also exercise caution with their diet, avoiding extremely hard foods like ice or nuts that could cause the crown, especially porcelain, to chip or fracture. Similarly, very sticky or chewy foods may pull at the crown and loosen the cement seal over time. Regular dental check-ups and professional cleanings every six months allow the dentist to monitor the crown’s condition and the health of the underlying tooth structure.