A chipped tooth represents a minor fracture of the enamel, the hard, protective outer layer of the tooth. This damage can range from a tiny, almost unnoticeable surface defect to a significant loss of tooth structure that exposes the sensitive inner dentin. While the enamel is the hardest substance in the human body, it is not indestructible, and once damaged, it cannot repair itself like bone. A chipped tooth is a common dental injury that often results in a rough or jagged edge, sometimes causing irritation to the tongue or gums.
Sudden External Trauma
A common cause of chipped teeth involves a sudden, high-impact force applied directly to the mouth or jaw. This acute trauma rapidly overwhelms the tooth’s structural integrity, causing a piece of the enamel to break away instantly. Common incidents include a fall, a direct blow to the face, or a collision during sports activities.
Sports injuries are a frequent source of this damage, particularly in activities involving physical contact or a high risk of falling. An unexpected elbow during basketball or a hard landing on a skateboard can generate enough force to fracture a tooth. Using a protective mouthguard is the most effective way to distribute impact force, preventing it from concentrating on a single tooth.
Accidents, such as car collisions or biting down on a fork, can also cause sudden chipping due to unexpected pressure. The resulting break often leaves a rough surface that may require prompt dental attention to prevent further damage or injury to the soft tissues of the mouth.
Chronic Stress and Repetitive Behaviors
Damage can occur gradually over time through repeated, lower-level forces that cause fatigue failure in the dental material. This involves the accumulation of microscopic defects until a small force finally causes a visible chip. Teeth grinding and clenching, known as bruxism, are a primary example of this chronic stress.
Bruxism, which often occurs unconsciously during sleep, subjects the teeth to immense and prolonged pressure, sometimes generating up to 250 pounds of force per square inch. This persistent motion slowly wears down the enamel and introduces micro-fractures that eventually lead to chipping.
Repetitive behaviors also contribute to this fatigue, such as habitually chewing on non-food items like pen caps, fingernails, or ice cubes. These habits place unnatural, uneven stress on the teeth, especially the cusps and edges. Biting down unexpectedly hard on a rigid object, like an unpopped popcorn kernel or a small bone fragment, can act as a sudden overload on an already fatigued tooth, resulting in a chip.
Structural Weakness and Existing Dental Conditions
A tooth may chip because its internal structure has been compromised beforehand, rather than from a traumatic external force. Advanced tooth decay, or cavities, weakens the tooth by eroding the enamel and dentin from the inside out. As decay spreads, it leaves the remaining material hollowed out and brittle, making it vulnerable to breaking under normal chewing pressure.
Existing dental restorations, such as large or aging fillings, can also undermine strength. A large filling means less natural, supportive tooth remains, increasing the risk of fracturing the surrounding material. Over time, these materials can shrink or fail at the margins, allowing decay to develop beneath them and further weakening the tooth.
Teeth that have undergone a root canal procedure are structurally weaker because the procedure removes the inner pulp. The tooth becomes more brittle and prone to fracture without the placement of a protective crown.
Enamel erosion is a further factor, caused by prolonged exposure to acid from dietary sources like citrus fruits and sodas, or from conditions like acid reflux. This acid exposure demineralizes the enamel, making the entire tooth surface softer and more susceptible to chipping from everyday forces.