Interproximal cavities, commonly called cavities between teeth, are a form of tooth decay that develops on the surfaces where adjacent teeth meet. These lesions are challenging to detect because they are hidden at the tight contact points between teeth. Individuals often remain unaware of their presence until the decay has progressed significantly, sometimes leading to substantial damage before symptoms appear. Regular dental check-ups and specialized diagnostic tools are the only reliable way to catch these silent problems.
Subtle Signs and Symptoms of Interproximal Cavities
While these cavities often remain asymptomatic, the earliest indications are usually subtle shifts in sensation or hygiene routine. A common early sign is a sudden, fleeting sensitivity to temperature extremes or sweet foods and beverages. This discomfort is typically localized to a specific area between two teeth and suggests the decay is beginning to breach the outer enamel layer.
A persistent feeling of food getting caught between a particular pair of teeth is another frequent indicator. This food impaction occurs because the decay has started to create a microscopic ledge, disrupting the smooth contact point. Pay attention if your dental floss consistently shreds, tears, or catches resistance in the same spot, as this friction can indicate a rough edge caused by an underlying cavity.
How Dentists Confirm Cavities Between Teeth
Because a visual inspection of the contact area is nearly impossible, dentists rely on advanced imaging to definitively diagnose interproximal decay. The primary tool for detecting these hidden lesions is the bitewing X-ray, which is taken during a routine examination. This type of radiograph is specifically angled to show the crowns of the posterior teeth and the bone level between them.
On a bitewing X-ray, areas of decay appear as darker or hazy regions because the demineralized enamel and dentin are less dense and allow more radiation to pass through. This visual contrast makes it possible to see the extent of the demineralization on the side walls of the tooth, often long before a physical hole has formed. The diagnostic process depends heavily on the X-ray, which provides a detailed, two-dimensional view of the decay’s depth and severity, guiding the appropriate treatment plan.
Why Interdental Spaces Are Vulnerable to Decay
The architecture of the mouth makes the interdental spaces an ideal environment for decay-causing bacteria to flourish. These areas have a tight contact point where two teeth meet, creating a confined space shielded from the cleansing action of saliva and toothbrush scrubbing. As a result, dental plaque, a sticky film of bacteria and food debris, is easily retained and concentrated in these narrow gaps.
Bacteria feed on carbohydrates, producing acids as a byproduct. These acids remain trapped between the teeth, steadily eroding the mineral structure of the enamel in a process called demineralization. Without the regular removal of this trapped plaque, typically through flossing, the acid attack is constant, leading to cavity formation. Anatomical factors, such as crowded or overlapping teeth, can further tighten these spaces, increasing the risk of decay.
Progression and Treatment Options
If an interproximal cavity remains undetected, the decay will progress inward through the tooth’s layers. Once the decay penetrates the hard, outer enamel, it rapidly spreads into the softer, more porous dentin layer beneath. This invasion of the dentin typically leads to a significant increase in tooth sensitivity and can result in a persistent toothache.
If the decay continues to advance, it will eventually reach the pulp chamber, which contains the tooth’s nerves. When this happens, the pulp becomes infected, causing intense pain, swelling, and potentially a dental abscess.
Treatment options vary depending on the decay’s depth. Small cavities may be reversed with professional fluoride treatments, a process called recalcification. More advanced decay requires a dental filling, where the decayed material is removed and the tooth is restored. If the infection has reached the pulp, a root canal procedure is necessary to save the tooth, and in severe cases, extraction may be the only option.