Interproximal caries is the clinical term for a cavity that forms on the surfaces between two adjacent teeth. These cavities develop in the tight spaces where teeth touch, making them challenging to see and clean effectively with a standard toothbrush. Unlike cavities on visible tooth surfaces, interproximal decay often remains hidden from plain sight, contributing to their progression before detection.
How Cavities Form Between Teeth
The formation of interproximal cavities begins with plaque accumulation, a sticky, colorless film composed of bacteria, food particles, and saliva. This film readily adheres to tooth surfaces, especially in the tight, less accessible areas between teeth where toothbrush bristles cannot easily reach. Bacteria within the plaque consume sugars and carbohydrates, producing acids that attack and demineralize tooth enamel, the hard, outer layer of the tooth. Over time, this continuous acid exposure weakens the enamel, creating a cavity. The sheltered environment between teeth allows plaque to thrive, making these areas highly vulnerable to decay.
Diagnosing Hidden Decay
Interproximal cavities frequently go unnoticed because their location makes them invisible during a simple visual inspection. Pain or sensitivity may not develop until the decay has progressed significantly. Dental X-rays, specifically bitewing X-rays, are the most effective method for detecting these hidden lesions. These X-rays provide a clear image of the crown portions of the upper and lower back teeth, allowing a dentist to visualize the areas between teeth and identify demineralized regions. X-rays offer the definitive view of interproximal decay, revealing its presence and approximate depth.
Treatment Approaches
Treatment for interproximal cavities depends on the extent of the decay. For very early-stage lesions, often called incipient caries, where demineralization is confined to the outer half of the enamel, non-invasive approaches can be effective. Fluoride treatments, applied as gels, varnishes, or through prescription toothpastes, can encourage remineralization of weakened enamel, potentially reversing early decay. Silver diamine fluoride (SDF) can halt or reverse incipient interproximal caries.
When the cavity has progressed beyond the enamel and into the softer dentin layer, a dental filling becomes the standard treatment. The decayed tooth structure is carefully removed, and the prepared space is then filled with a restorative material such as composite resin, amalgam, or porcelain. This restores the tooth’s shape, function, and integrity, preventing further bacterial invasion. Untreated decay can lead to more extensive issues, potentially requiring root canals or crowns if the decay reaches the inner pulp chamber.
Effective Prevention Methods
Preventing interproximal cavities focuses on disrupting plaque accumulation in hard-to-reach areas. Daily flossing is highly recommended, as toothbrush bristles cannot adequately clean the surfaces between teeth. Flossing physically removes food particles and bacterial plaque from these tight spaces, preventing acid production and enamel erosion.
Beyond traditional string floss, interdental brushes or water flossers can also be effective tools for cleaning between teeth, especially for individuals with larger gaps or orthodontic appliances. Incorporating a low-sugar diet reduces the fuel available for acid-producing bacteria, lowering the overall risk of decay. Regular dental check-ups and professional cleanings are also important as they allow for early detection of any developing issues and thorough removal of plaque and tartar that at-home care might miss.