Wisdom teeth, officially known as third molars, are the final set of teeth to emerge, typically appearing between the ages of 17 and 25. Like all other teeth, third molars are made of enamel and dentin, making them fully susceptible to dental decay. The direct answer to whether wisdom teeth can get cavities is a definitive yes, and their unique position at the very end of the dental arch makes them highly prone to this condition.
Why Wisdom Teeth Are Prone to Decay
The primary reason third molars are susceptible to decay is their anatomical location. Positioned far back in the jaw, they are extremely difficult to reach with a standard toothbrush or dental floss. This limited accessibility means that plaque—a sticky film of bacteria—and food debris frequently accumulate on their surfaces.
Inadequate cleaning allows acid-producing bacteria to erode the protective enamel layer, leading to cavity formation. Furthermore, many wisdom teeth do not erupt fully or correctly, a condition known as impaction. An impacted tooth may grow in at an angle, creating a tight, impossible-to-clean space between it and the adjacent second molar, trapping plaque and debris.
When a wisdom tooth is only partially erupted, a flap of gum tissue, called an operculum, can cover a portion of the chewing surface. This soft tissue creates a dark, moist pocket that acts as a perfect breeding ground for bacteria and food particles, often leading to localized infection or decay underneath the flap.
Recognizing Symptoms and Diagnosis
A cavity in a wisdom tooth may not always present with immediate or obvious pain, but several signs can indicate a problem. Persistent, dull pain in the back of the jaw is a common symptom, often worsening when chewing or applying pressure. Sensitivity to hot or cold temperatures, or an uncomfortable sensation when consuming sweet foods, can signal that decay has reached the underlying dentin layer.
Other noticeable signs include a visible hole, pit, or dark spot on the tooth’s surface, or localized swelling and redness in the surrounding gum tissue. A foul taste in the mouth or chronic bad breath may also result from trapped bacteria associated with advanced decay or infection.
A dental professional confirms the diagnosis through visual inspection and diagnostic imaging. During an exam, the dentist probes the tooth’s surface to detect soft spots indicative of decay. Dental X-rays, particularly panoramic radiographs, are essential because they reveal the full extent of the decay, the exact position of the wisdom tooth, and its relationship to neighboring teeth. This imaging is critical for determining the appropriate treatment plan.
Treatment Decisions: Filling Versus Extraction
Once a wisdom tooth cavity is diagnosed, the decision between restoring the tooth with a filling and removing it through extraction depends on several factors. A filling is generally considered an option only if the decay is small, limited to the enamel or outer dentin, and the tooth is fully erupted and correctly aligned. The tooth must be positioned to allow the dentist to perform a high-quality restoration, and the patient must be able to keep the filled tooth clean afterward.
Extraction, however, is frequently the preferred course of action for third molars, even with relatively minor decay. This preference is driven by the tooth’s poor long-term prognosis due to its compromised position and cleaning difficulty. If the cavity is large, has penetrated deep toward the dental pulp, or if the tooth is impacted or partially erupted, removal is strongly recommended.
An impacted wisdom tooth with decay is often impossible to restore effectively, and attempting a filling in a hard-to-access area can lead to a compromised restoration that fails quickly. Deep decay or infection in a wisdom tooth also poses a direct risk to the adjacent second molar, which is a functional tooth. Removing the affected third molar eliminates the decay, prevents potential damage to the neighboring tooth, and removes a source of future chronic infection or pain. The final decision is a clinical judgment based on the size and location of the decay, the tooth’s alignment, and the patient’s overall oral health.