An intermittent toothache is a common but often misleading symptom. This pattern of discomfort can lead people to believe the problem has resolved itself, but this is rarely the case. The temporary relief is merely a pause in the signaling of an underlying structural or biological issue that requires professional diagnosis. While the pain is not constant, its presence confirms an irritated nerve or exposed dentin, which will continue to flare up until the source is addressed.
Primary Dental Conditions Causing Intermittent Pain
One of the most frequent causes of sporadic pain is reversible pulpitis, which occurs when tooth decay has reached the dentin layer beneath the enamel. At this stage, the inflammation of the dental pulp—the tissue containing nerves and blood vessels—is mild and can still heal if the decay is removed. The pain is triggered only by an external stimulus like cold or sugar and disappears within seconds of the irritant being removed.
A second cause is Cracked Tooth Syndrome (CTS), where a micro-fracture exists that is often too small to see on standard X-rays. This condition classically causes a sharp, brief pain when pressure is applied to the tooth during biting or chewing. The pain stops immediately when the biting pressure is released because the two sides of the crack snap back together, removing the irritation from the inner pulp.
Intermittent sensitivity can also arise from receding gums that expose the root surface, which lacks the protective enamel layer. The exposed dentin is sensitive to air, temperature changes, and touch, leading to transient, sharp discomfort. Chronic bruxism, or clenching and grinding, places excessive force on teeth and surrounding ligaments, resulting in a dull, intermittent ache often noticeable upon waking or during periods of high stress.
How External Triggers Provoke and Relieve Pain
The “come and go” nature of this pain is directly related to the stimulus-response cycle that occurs when the tooth’s protective layers are compromised. Thermal sensitivity is explained by the hydrodynamic theory, which proposes that fluid flows within the microscopic dentinal tubules that connect the outer tooth structure to the inner pulp. When exposed dentin is subjected to heat or cold, the rapid expansion or contraction of this tubule fluid creates pressure changes that stimulate the mechanoreceptors on the pulpal nerves.
Because the pulp is merely irritated—a state known as reversible pulpitis—the nerve impulse is activated only while the temperature stimulus is present. The sharp pain subsides almost instantly once the hot or cold item is removed. This differs from irreversible pulpitis, where inflammation is severe and the pain lingers for minutes or becomes spontaneous. Similarly, the brief, intense pain caused by biting down on a cracked tooth is a mechanical response: pressure separates the fractured segments, stimulating the nerve, and the pain ceases the moment the bite is released.
Referred Pain and Non-Dental Sources
Not all pain felt in the mouth originates from the teeth themselves, and non-dental sources can also present as fluctuating discomfort. One common alternative is a sinus infection, or sinusitis, where inflammation and pressure build up in the maxillary sinuses located above the upper back teeth. This pressure can mimic a toothache in the upper jaw, and the pain often fluctuates based on changes in head position or barometric pressure.
Another source is Temporomandibular Joint Disorder (TMD), which affects the jaw joints and the surrounding muscles. Dysfunction in this area can cause pain that radiates, or is “referred,” to the teeth, face, neck, and temples. The intensity of TMD-related tooth pain is often intermittent, worsening with activities like chewing or speaking, and can be influenced by stress levels that cause increased muscle tension. In some instances, nerve conditions like neuralgia or certain types of tension headaches can manifest as a throbbing or shooting pain felt directly in the teeth.
Steps to Take and What to Expect at the Dentist
The first step when experiencing intermittent tooth pain is to schedule an appointment with a dental professional. While waiting for the visit, you can temporarily manage the symptoms by avoiding the specific triggers you have identified, such as very hot or cold foods. Over-the-counter pain relievers can help reduce any underlying inflammation but should not be viewed as a long-term solution.
To assist the dentist, it is helpful to track the pain’s characteristics, noting what triggers it, how long the pain lasts, and if it is sharp or dull. During the diagnostic process, the dentist will conduct a thorough visual and clinical examination, often using dental X-rays to check for decay or infection. They may perform specific diagnostic tests, such as applying cold to the tooth (vitality testing) to assess the nerve’s response or using a bite stick to isolate a cracked tooth.
Treatment is entirely dependent on the diagnosis. A small cavity causing reversible pulpitis may only require a simple filling, while pain from bruxism might be treated with a custom night guard. If the pain is caused by a significant crack or if the pulpitis has progressed to an irreversible state, a more complex procedure like a dental crown or root canal may be necessary.