Tooth nerve pain, often described as a sharp, throbbing, or constant ache, signals an underlying issue within the tooth or its surrounding structures.
Damage to the Tooth’s Protective Layers
The outer layers of a tooth, the enamel and dentin, serve as protective barriers for the sensitive inner pulp. Enamel, the outermost and hardest layer, can be compromised by dental decay. When bacteria produce acids, they erode enamel, creating holes. If untreated, this decay can progress through the dentin, a softer layer beneath the enamel, eventually reaching the pulp and its nerves.
Physical damage, such as cracks, chips, or fractures, also breaches the tooth’s integrity. These openings allow external irritants, including bacteria, temperature changes, and pressure, to reach the dentin’s microscopic tubules, which lead directly to the pulp. Even worn or damaged fillings and crowns can create pathways for irritation, contributing to nerve pain. When the dentin is exposed, teeth become sensitive to hot, cold, or sweet stimuli.
Inflammation of the Pulp (Pulpitis)
The direct cause of tooth nerve pain often involves pulpitis, the inflammation of the dental pulp. The pulp, located at the tooth’s core, contains nerves, blood vessels, and connective tissues. When irritants, such as bacteria from decay or toxins, reach the pulp, they cause it to swell. Since the pulp is encased within the rigid walls of the tooth, this swelling creates pressure that directly stimulates the nerve endings, leading to pain.
Pulpitis can manifest in two forms: reversible and irreversible. Reversible pulpitis means the inflammation is mild, and the pulp can heal if the irritant is removed, such as by treating a cavity. Pain from reversible pulpitis is often brief and occurs when a stimulus like cold or sweets is applied, quickly subsiding once the stimulus is removed. In contrast, irreversible pulpitis indicates severe inflammation where the pulp cannot recover, often requiring more extensive treatment like a root canal or extraction. Pain in irreversible pulpitis can be more intense, spontaneous, and linger for minutes or hours even after a stimulus is removed.
Issues Affecting Tooth Roots and Surrounding Areas
Nerve pain in a tooth does not always originate from damage to the tooth’s crown; it can also stem from problems affecting the tooth’s roots or supporting structures. Gum recession is a common issue where the gum tissue pulls back, exposing the sensitive root dentin. Unlike enamel, root dentin lacks a protective covering, making it highly vulnerable to external stimuli like temperature changes and touch, leading to sensitivity and pain.
Periodontitis, an advanced form of gum disease, involves inflammation and infection of the tissues and bone supporting the teeth. While often painless initially, severe periodontitis can cause irritation to the nerves or the periodontal ligament, which anchors the tooth to the jawbone. Another factor is bruxism, the habitual grinding or clenching of teeth. The excessive force from bruxism can wear down enamel and dentin, exposing nerves, and can also inflame the pulp or the periodontal ligament, resulting in nerve-like pain and sensitivity.
Dental Abscesses and Infections
Severe infections can lead to intense tooth nerve pain, often as a dental abscess. An abscess is a pocket of pus that forms due to bacterial infection, typically from deep decay or pulpitis. Pus accumulation creates significant pressure within the tooth or surrounding bone, directly pressing on nerves and causing severe, throbbing pain.
Abscesses can be categorized based on their location. A periapical abscess forms at the tip of the tooth root, usually stemming from an infection within the tooth’s pulp. A periodontal abscess, conversely, develops in the gums or bone supporting the tooth, often as a result of gum disease. Both types of abscesses can cause intense, throbbing pain, facial swelling, fever, or a bad taste in the mouth. If untreated, the infection can spread beyond the tooth, potentially causing serious health complications.
Other Contributing Factors
Other factors can also lead to tooth nerve pain. Dental trauma, such as a direct blow, might not always result in a visible crack but can still damage the tooth’s pulp or supporting ligaments. This internal damage can lead to inflammation and subsequent nerve pain.
Referred pain occurs when discomfort from one area is felt in a tooth. For example, sinus infections can cause pain in upper teeth due to their proximity to sinus cavities. Temporomandibular joint (TMJ) disorders, affecting the jaw, can also cause pain that radiates to the teeth. Even conditions like heart problems can cause referred pain to the teeth.