A dental crown, often referred to as a cap, is a custom-made restoration designed to fit completely over a damaged or weakened tooth, encasing the entire visible portion above the gum line. This procedure restores the tooth’s shape, size, strength, and appearance. Dental crowns are one of the most routine restorative treatments performed today. Their frequency stems directly from the commonality of the underlying dental issues they are designed to fix.
Essential Dental Conditions Requiring Crowns
The primary indication for a crown is a significant compromise to the tooth’s structural integrity that cannot be resolved with a simpler filling. When tooth decay or an existing filling has removed more than half of the original chewing surface, the remaining tooth walls become fragile. A traditional filling in such a large cavity would not provide the necessary support and could lead to a fracture of the tooth.
A tooth that has undergone root canal therapy almost always requires a crown because the procedure compromises the tooth’s natural support structure. To access the infected pulp chamber, internal material is removed, leaving the outer shell brittle and susceptible to cracking. Placing a full coverage crown over this treated tooth distributes occlusal (biting) forces evenly, protecting the tooth from breaking.
Crowns are also the standard treatment for teeth with significant fractures or vertical cracks that extend deep into the tooth structure. These extensive cracks threaten the pulp and can lead to tooth loss if not stabilized. The crown binds the fractured pieces together, preventing the crack from propagating further and sealing the inner structures from contamination. Extensive wear from teeth grinding or severe acid erosion can also diminish the tooth’s height, necessitating a crown to restore proper bite alignment and protect the vulnerable inner dentin.
Measuring the Commonality of Crowns
Dental crowns are a staple of modern restorative dentistry, reflecting the high incidence of tooth damage over a lifetime. Single crown placement is consistently ranked as one of the most common restorative procedures performed annually in the United States. This frequency is driven by the number of older, large fillings that eventually fail, the millions of root canals performed each year, and general dental trauma. Millions of adults have at least one crown or bridge restoration. Since materials have an expected lifespan, these procedures must be repeated over time, sustaining the crown as a standard treatment in nearly every dental practice.
Maintaining the Lifespan of a Dental Crown
A well-placed dental crown is a durable restoration, typically lasting between 5 and 15 years, depending on patient habits. The most common point of failure is secondary decay at the margin, the seam where the crown meets the natural tooth structure at the gum line. Plaque easily accumulates in this narrow, difficult-to-clean area, leading to decay in the underlying tooth material.
To maximize the crown’s lifespan, rigorous oral hygiene focusing on the crown margin is mandatory. Daily flossing is important to disrupt the plaque film around the base of the crown. Patients must also avoid habits that place excessive stress on the restoration, such as chewing on ice or hard candies, which can cause chipping or bonding cement failure. Regular checkups are necessary to allow the dentist to inspect the margin for leakage, cracks, or signs of gum recession.
Alternatives to Full Coverage Crowns
While a full coverage crown is the most comprehensive solution, it requires removing a significant amount of healthy tooth structure for preparation. When the damage is moderate, more conservative indirect restorations are often chosen instead. These alternatives are custom-made and bonded into place, including inlays and onlays.
An inlay is used when the decay or damage is confined entirely to the chewing surface, situated between the cusps (the raised points of the tooth). An onlay is a more extensive restoration, often referred to as a partial crown, because it covers one or more cusps. The use of an inlay or onlay is preferred when the remaining cusps are strong and intact, as they preserve more natural tooth material than a crown, which covers all cusps. For very minor repairs, a large composite filling may sometimes be an option, but it lacks the customized strength and long-term durability of the indirect inlay or onlay.