Veneers are thin, custom-made shells, typically crafted from porcelain or composite resin, which are bonded to the front surface of the teeth to improve appearance. Developing cavities is still possible after receiving veneers because the natural tooth structure remains susceptible to decay. While the veneer material itself resists decay, it only covers the visible front portion of the tooth. The back, sides, and root surfaces remain exposed to the oral environment and the bacteria that cause dental caries.
How Decay Forms Around and Beneath Veneers
A veneer does not completely encase the tooth, so the underlying natural structure is not fully shielded from decay. The primary area of concern is the “margin,” the seam where the edge of the veneer meets the natural tooth structure, often near the gum line. This microscopic junction is a vulnerable site for plaque accumulation if not meticulously cleaned.
Bacteria and food debris collect at this margin, especially between teeth, leading to plaque formation. These bacteria metabolize sugars to produce acids that demineralize the natural enamel and dentin. If the bond or seal is compromised, bacteria can penetrate and cause decay on the underlying tooth structure, known as secondary or recurrent decay. This process is problematic because the restoration hides the early signs of a cavity from casual inspection.
Specific Risk Factors That Increase Vulnerability
Several factors increase the likelihood of decay by compromising the integrity of the protective seal. A poorly fitting veneer or one with a chipped edge creates a physical gap where plaque and bacteria easily become trapped. This breach provides a direct pathway for acid to attack the exposed tooth material.
Gingival recession, where the gum tissue pulls back, is another significant risk because it exposes the root surface. The root surface is covered by cementum, which is much softer and less resistant to decay than enamel. Exposing this softer tissue at the margin drastically increases the risk of decay. Additionally, conditions like dry mouth (xerostomia) or a diet high in sugar and acid reduce the mouth’s natural ability to neutralize acids and wash away food particles. Over time, even a perfectly placed veneer can be compromised if the bonding material degrades, creating microscopic access points.
Essential Strategies for Prevention and Maintenance
Maintaining excellent oral hygiene is the most effective defense against decay. Brushing at least twice daily is required using a soft-bristled, non-abrasive toothbrush to avoid scratching the veneer material or damaging the gum line. Use a gentle, fluoride toothpaste, as abrasive materials can dull the veneer’s finish and weaken the margin.
Daily flossing is necessary for removing plaque from the interproximal spaces and the critical margin. Traditional string floss must be used carefully to avoid snapping it against the gum tissue, which could lead to recession. Water flossers are highly recommended as they effectively clean the margin and between teeth without risk of damage. Rinsing with an alcohol-free mouthwash can also help reduce the bacterial load.
Dietary and Professional Care
Dietary modifications are also helpful, including limiting the consumption of highly acidic and sugary foods and drinks. These items increase mouth acidity, promoting the decay process around the exposed natural tooth structure. Regular professional dental checkups are mandatory for monitoring the health of the veneers and underlying teeth. The dentist will use routine X-rays to detect decay beneath the veneer, which is often invisible until advanced.
Clinical Options When Decay Occurs
If decay is detected, the treatment approach depends on the extent and location of the cavity. If the decay is small and confined to the exposed margins, the dentist may treat the cavity without removing the entire veneer. The minor decay can be removed, and the tooth repaired with a small filling material before the veneer is resealed. The goal is to preserve the existing restoration whenever possible.
If the decay is extensive, especially if it has penetrated beneath the main body of the veneer, the restoration must be removed. The veneer is typically cut off to access the underlying tooth structure. After the decay is cleaned out and the tooth is restored with a filling, a completely new veneer must be fabricated and bonded. In cases of severe decay that significantly compromises the tooth structure, a full-coverage crown may be required instead of a new veneer for structural support.