Dental crowns protect and restore damaged teeth. Concerns often arise about their long-term aesthetic stability, particularly regarding color changes. While crowns are designed for durability and a natural appearance, their color can be affected by various factors.
Crown Materials and Their Color Properties
A dental crown’s color stability largely depends on its material. Porcelain, a common ceramic material, is favored for its natural appearance and resistance to staining. Porcelain crowns are highly customizable to match existing tooth shades and maintain their brightness due to their non-porous nature. However, while porcelain is stain-resistant, it is not entirely immune to all forms of color change.
Zirconia crowns, made from zirconium dioxide, offer a balance of strength and aesthetics. This material resists staining and wear, making it a good choice for both front and back teeth. Zirconia is also non-porous, contributing to its color stability. Porcelain-fused-to-metal (PFM) crowns combine a metal base with a porcelain exterior. These crowns are durable, but the underlying metal can become visible as gums recede, leading to a grayish discoloration at the gum line. Metal crowns, typically made from gold or other alloys, are strong but do not blend with natural tooth color, making them more suitable for less visible teeth.
Common Causes of Color Change
Several factors can lead to a dental crown changing color over time, stemming from external and, less commonly, internal influences. Extrinsic stains are the most frequent. These originate from consuming pigmented foods and beverages, such as coffee, tea, red wine, and certain berries. They can adhere to the crown’s surface, particularly if it becomes rough or loses its original glaze.
Tobacco use is another significant cause of yellowish-brown discoloration on crowns. Poor oral hygiene also contributes to color change by allowing plaque and tartar to accumulate on the crown’s surface, leading to dullness and staining. Over time, this buildup can make the crown appear darker.
Less common intrinsic changes can occur if the underlying natural tooth discolors, which may show through thinner crown materials. The crown material itself can experience changes due to aging or wear, affecting its luster.
Keeping Your Crowns Bright
Maintaining the color and appearance of dental crowns involves consistent oral hygiene practices and mindful dietary choices. Brushing at least twice daily with a soft-bristled toothbrush and fluoride toothpaste helps remove plaque and surface stains. Daily flossing is equally important to clean around the crown and gum line, preventing plaque and food particle buildup. Using an antibacterial mouthwash can further reduce bacteria and maintain oral hygiene.
Limiting the consumption of highly pigmented foods and beverages, such as coffee, tea, red wine, and dark berries, can significantly reduce extrinsic staining. If these items are consumed, rinsing the mouth with water immediately afterward or using a straw for dark beverages can help minimize contact with the crown. Avoiding tobacco products is also crucial, as they are a leading cause of staining for both natural teeth and crowns. Regular dental check-ups and professional cleanings are important for removing stubborn stains and assessing the crown’s condition, helping to preserve its appearance.
Options for Discolored Crowns
If a dental crown has already discolored, professional solutions are available, though options are limited since crowns cannot be whitened like natural teeth. Crown materials like porcelain and zirconia are non-porous and do not absorb bleaching agents. For extrinsic stains, a professional cleaning and polishing by a dentist can effectively remove surface discoloration. This method is effective if the discoloration is superficial and not due to deeper material changes.
For more significant discoloration, other cosmetic dental procedures might be considered. If the natural teeth surrounding the crown have whitened, making the crown appear darker by comparison, dentists may recommend whitening the natural teeth to match the existing crown, or whitening teeth first and then replacing the crown to match the new shade. For a more comprehensive change, options like applying a thin layer of composite resin through bonding or placing a porcelain veneer over the discolored crown may be possible. However, the most definitive solution for a significantly discolored crown is often complete crown replacement, especially if the crown is old, damaged, or the discoloration is inherent to the material.