A cavity (dental caries) is a hole in a tooth from decay. Acids from mouth bacteria erode the tooth’s hard outer surface, causing this decay. Though often associated with pain, cavities don’t always cause discomfort, especially in initial stages. Pain intensity depends on decay progression.
How Cavities Cause Discomfort
Tooth decay begins when bacteria convert food sugars into acids. These acids attack the tooth’s outermost layer, the enamel, a hard, protective mineralized tissue. Initially, this process, called demineralization, may appear as small white spots on the tooth surface, causing no pain.
As decay continues, it can create a hole in the enamel. If decay penetrates through the enamel and reaches the dentin, discomfort may begin. Dentin is softer than enamel and contains thousands of microscopic tubules that lead directly to the tooth’s pulp, the innermost part containing nerves and blood vessels. When decay reaches this sensitive dentin layer, external stimuli like hot, cold, or sweet foods can irritate the nerves, leading to sensitivity or pain.
If the cavity is left untreated, bacteria and acids can advance further into the pulp. When the pulp becomes infected or inflamed, it can cause significant pain. Since the pulp is enclosed within the tooth, swelling has nowhere to expand, which can put pressure on the nerves and result in persistent pain.
Progression of Cavity Pain
Cavity pain varies greatly depending on the extent of tooth decay. In earliest stages, when decay is confined to the enamel, there are no noticeable symptoms or pain. As the cavity progresses into the dentin, individuals might experience mild to sharp pain, particularly when consuming sweet, hot, or cold foods and drinks. This sensitivity may feel like a stinging or burning sensation that is temporary.
When decay deepens and reaches the pulp, the pain can become more severe and persistent. This may manifest as a throbbing, constant ache, or sharp pain that occurs even without external stimuli. Biting down can also trigger sharp pain. If an infection develops and leads to an abscess, the pain can become intense, radiating into the jaw or face, and may be accompanied by swelling, fever, or a foul taste in the mouth.
Other Sources of Tooth Pain
While cavities are a common cause of tooth pain, discomfort can stem from various other issues. Gum disease, such as gingivitis or periodontitis, can lead to tooth pain as gums become inflamed and recede, potentially exposing sensitive tooth roots. Cracked or fractured teeth can also cause sharp pain, especially when chewing, because pressure can irritate the tooth’s inner pulp.
Dental abscesses, pockets of pus caused by bacterial infections, can develop from causes other than cavities, such as trauma to the tooth. Teeth grinding (bruxism) can wear down tooth enamel over time, exposing the dentin and leading to sensitivity or pain. Pain can also arise from exposed tooth roots due to gum recession, or even from non-dental issues like sinus infections, where pressure in the sinuses can be felt as pain in the upper teeth.
Seeking Professional Dental Care
Ignoring tooth pain or sensitivity is not advisable, as early intervention can prevent more severe dental problems. If tooth pain persists for more than a day or two, intensifies, or is accompanied by swelling in the face or gums, contact a dentist promptly. These symptoms can indicate a deepening infection or other serious issues that require immediate attention.
A dentist will conduct a thorough examination, often including X-rays, to accurately diagnose the cause of the pain. This process helps determine the extent of decay or other dental conditions. Regular dental check-ups are important for preventing cavities and other oral health problems. These routine visits allow dentists to identify and address issues in their early stages, often before pain even begins.