A cavity that forms between two teeth is known as an interproximal cavity, a common type of dental decay. This location, where adjacent teeth touch, creates a sheltered area where plaque and bacteria flourish undisturbed by normal brushing. Because the decay develops on the hidden side of the tooth, these lesions often go unnoticed until they have progressed significantly. Successful treatment depends on accurate early detection and selecting a method appropriate for the extent of the enamel and dentin damage.
Detecting Hidden Interproximal Cavities
Interproximal decay poses a unique detection challenge because the tight space between teeth makes visual identification almost impossible for both the patient and the dentist. The decay typically starts beneath the point of contact, where toothbrush bristles cannot reach, meaning a physical examination often reveals nothing. By the time a patient notices symptoms like sensitivity to cold or sweets, the decay has usually penetrated the outer enamel layer. This discomfort signals that the lesion has reached the underlying dentin, indicating more advanced decay.
For this reason, dental radiographs, specifically bitewing X-rays, are an indispensable diagnostic tool for identifying these hidden lesions. Bitewing images are taken with a small film or sensor, allowing the dentist to visualize the contact points and bone level between the teeth. Interproximal cavities appear as distinct dark or radiolucent areas on the X-ray image, indicating the loss of dense tooth structure. The dental professional uses these images to precisely assess the depth of the lesion and its proximity to the pulp chamber.
Treatment Options for Interdental Decay
The chosen treatment for an interproximal cavity is directly dictated by how far the decay has advanced through the tooth layers. When detected in its earliest stages, while the lesion is confined to the outer enamel, the decay may be reversible. In these cases, the dentist may opt for a non-invasive approach using high-concentration fluoride varnish or specialized remineralization pastes. These professional topical treatments help to harden the enamel structure by introducing mineral ions, potentially halting the decay process.
If the decay has progressed deeper into the enamel or reached the dentin, a dental filling becomes the standard treatment. The dentist must access the decayed area, typically by preparing the tooth from the chewing surface, to completely remove the infected tooth material. For interproximal areas, composite resin is the material of choice due to its ability to bond directly to the tooth structure and its tooth-colored aesthetic appearance. This restoration process rebuilds the missing tooth structure and restores the natural contour and contact point between the teeth.
Extensive Restorations
When the cavity is exceptionally large, having caused significant structural compromise, more extensive restorations are necessary to ensure long-term integrity. Inlays or onlays are laboratory-fabricated restorations that fit precisely over the prepared tooth structure, offering greater strength than a direct filling. If a substantial portion of the tooth’s structure is gone, a full coverage crown may be required to protect the tooth from fracture. In the most severe instances, where the bacteria have reached the pulp, a root canal procedure is necessary to remove the infected tissue and save the tooth from extraction.
Targeted Prevention Strategies
Preventing interproximal decay requires specific hygiene practices that target the spaces a toothbrush cannot effectively clean. Daily flossing is the single most effective method for disrupting the bacterial plaque that accumulates between the teeth. To be effective, the floss must be guided gently between the teeth, curved into a C-shape against one tooth surface, and slid carefully below the gum line. This process should be repeated for the adjacent tooth surface to ensure both sides of the contact point are cleaned.
Supplemental Cleaning Tools
Supplemental tools can enhance this targeted cleaning, especially for individuals with larger gaps or dexterity challenges. Interdental brushes, which resemble tiny pipe cleaners, are designed to fit into the spaces between teeth to mechanically scrub the surfaces. Water flossers use a pressurized stream of water to flush out food debris and loose plaque from the interproximal spaces and below the gum line.
Using topical fluoride is another strategy to strengthen the enamel in these susceptible areas. Fluoride rinses or prescription-strength fluoride toothpastes can deliver a higher concentration of the mineral to the interproximal surfaces. This helps to make the enamel more resistant to the acid produced by plaque, offering an additional layer of protection where decay is most likely to begin. Consistent execution of these targeted hygiene habits is the most reliable way to prevent the formation of a hidden cavity between teeth.