A dental filling restores a tooth damaged by decay, but pain developing or persisting strongly a week later suggests an underlying problem requiring professional attention. While mild, short-term sensitivity to temperature is common and should fade within a few days, delayed discomfort is not a typical part of healing. This pain warrants investigation into the mechanical, structural, or biological causes within the tooth to restore comfort and health.
Mechanical Stress from an Uneven Bite
One of the most frequent causes of delayed pain is a slightly over-contoured filling, often called a “high spot.” When the filling sits marginally above the surrounding tooth structure, it creates premature contact when the upper and lower teeth meet. This elevation causes the filled tooth to receive a disproportionate amount of force during chewing and clenching.
The excessive pressure irritates the periodontal ligament, which anchors the tooth within the jawbone, causing sharp pain when biting down or grinding. Because the tooth is numb during the procedure, the unevenness often reveals itself only after the anesthesia wears off. This mechanical issue is usually the easiest to fix, requiring only a quick adjustment by the dentist to smooth the high spot and re-establish an even bite.
Delayed Pulp Irritation
The pulp is the soft tissue inside the tooth that contains the nerves and blood vessels. It can react to the trauma of the filling procedure, especially if the original decay was deep, leading to inflammation known as pulpitis. The severity of this inflammation determines if the condition is reversible or irreversible.
Reversible pulpitis involves mild inflammation where the pulp can still heal itself once the irritant, such as the initial decay or procedural trauma, is removed. Symptoms typically include sharp, fleeting pain or sensitivity to cold that disappears within a few seconds of the stimulus being removed. This sensitivity should gradually improve over the course of a few weeks as the nerve tissue calms down.
If the pulp does not recover, the condition progresses to irreversible pulpitis, indicating severe and permanent nerve damage. This is characterized by intense, spontaneous pain that may throb and often lingers for more than 30 seconds after cold exposure. Pain that is exacerbated by heat or that wakes you up at night strongly indicates irreversible damage. In this scenario, the dying pulp tissue requires root canal treatment to remove the infected tissue and save the tooth.
Structural Issues and Cracks
Pain emerging after the initial week can be caused by a compromise to the structural integrity of the tooth or the filling. One possibility is microleakage, where a microscopic gap forms between the filling and the tooth structure. This gap allows oral bacteria and fluids to penetrate underneath the filling, leading to new decay or infection near the pulp.
More commonly, the pain may signal a crack in the tooth, which is often difficult to detect visually. The drilling and filling process, combined with biting forces, can cause or exacerbate a hairline fracture. A cracked tooth causes a sharp, sudden pain that appears specifically when biting down and quickly releasing the pressure. This intense, fleeting pain is distinct from the lingering throbbing of pulpitis.
Actionable Steps and Urgent Symptoms
If pain persists or worsens beyond the first week, contacting the dentist for an evaluation is the first step. A persistent sharp pain when biting down suggests an uneven bite or a possible tooth crack that needs immediate assessment. Do not wait for pain to resolve if it is constant or intensifying.
Specific symptoms necessitate an urgent dental visit, as they suggest a severe underlying infection or nerve issue. These include constant throbbing pain that interferes with sleep or cannot be managed with medication. Swelling in the gums or face near the filled tooth, a fever, or a bad taste in the mouth are signs of a potential abscess or spreading infection. Prompt professional care is essential, as ignoring these symptoms can lead to more extensive treatments.