Tooth wear is the gradual loss of hard tooth structure resulting from forces distinct from bacterial decay. Understanding the specific cause is essential for effective management, as treatment varies depending on the type of wear. Tooth wear is broadly categorized into three main types: attrition (tooth-to-tooth friction), abrasion (wear from external contact), and erosion (chemical dissolution by acid). Identifying the specific factors at play is important because tooth enamel, the hardest substance in the human body, cannot regenerate once lost.
Mechanical Stress from Grinding and Brushing
Physical forces are a major contributor to the loss of tooth material, primarily categorized as attrition or abrasion. Attrition involves direct contact between opposing teeth, most commonly caused by bruxism, or teeth grinding and clenching. This non-functional activity often occurs unconsciously during sleep or in response to stress. The intense force exerted during bruxism is far greater than normal chewing pressure, leading to the rapid, uniform flattening of the biting surfaces.
This excessive friction wears away the outer enamel, resulting in shiny, flat spots or facets on the teeth, and may cause chipping along the edges. As the enamel layer thins, the softer, yellowish dentin beneath becomes exposed. This exposure accelerates the wear process and increases tooth sensitivity. Attrition can also be exacerbated if chewing teeth are missing, forcing the front teeth to bear excessive pressure during biting.
Abrasion is the mechanical wearing away of tooth structure from contact with foreign objects, not other teeth. The most frequent source is overly aggressive or incorrect oral hygiene practices, such as brushing too hard with a stiff-bristled toothbrush. This action typically causes characteristic V-shaped notches or grooves to form near the gumline, where the enamel is thinnest.
The use of highly abrasive toothpastes can intensify the effects of abrasion, even when brushing technique is correct. Abrasion also stems from certain habits, including chewing on non-food items like pen caps or fingernails. Furthermore, friction caused by an oral piercing constantly rubbing against a tooth surface contributes to this wear. These external forces gradually scrape away the enamel and dentin.
Chemical Erosion from Acidic Substances
Chemical dissolution of the tooth structure, known as erosion, occurs when acids soften and strip away the enamel without bacterial involvement. This process, called demineralization, begins when the pH level in the mouth drops below approximately 5.5. This low pH causes calcium and phosphate ions to leach out of the enamel structure. Erosion can come from external sources, such as dietary acids, or internal sources related to digestive issues.
Extrinsic erosion is linked to consuming highly acidic foods and drinks, including citrus fruits, carbonated soft drinks, sports beverages, and wine. The erosive potential of these items is determined by their low pH, titratable acidity, and frequency of exposure. Sipping acidic drinks repeatedly, or swishing them in the mouth, prevents saliva from neutralizing the acid. This allows the demineralization process to continue unchecked.
Intrinsic erosion is caused by strong gastric acid contacting the teeth, most commonly due to gastroesophageal reflux disease (GERD) or chronic vomiting. GERD allows stomach acid to flow into the mouth, often occurring during sleep when saliva production is reduced. This is damaging because saliva, which normally buffers acids, is less available to protect the teeth. The pattern of intrinsic erosion often presents on the palatal surfaces of the upper front teeth and the chewing surfaces of the back teeth.
Underlying Dental and Health Factors
Beyond daily habits and acid exposure, certain structural and systemic issues can contribute to or accelerate tooth wear. A primary factor is malocclusion, or an improper bite, where the upper and lower teeth do not align correctly. This misalignment causes uneven distribution of chewing forces, meaning certain teeth bear excessive pressure during function.
The resulting uneven contact leads to accelerated attrition in specific areas, creating localized wear patterns. Correcting the malocclusion often becomes a prerequisite for successful long-term management of the wear. Furthermore, a reduction in salivary flow, often associated with certain medications, diminishes the mouth’s natural ability to neutralize acids and wash away abrasive particles. This increases the risk for all types of wear.
Developmental defects that affect enamel formation can also make teeth inherently more vulnerable to wear. Conditions like amelogenesis imperfecta are genetic disorders that result in enamel that is structurally weak, thin, or soft from eruption. This compromised outer layer is brittle and prone to rapid chipping and wear, even from normal chewing forces. Consequently, the underlying dentin is exposed sooner, leading to heightened sensitivity and faster deterioration.
The simple passage of time plays a role in the cumulative effect of wear. While some attrition is a natural consequence of a lifetime of chewing, advanced age means the teeth have been subjected to decades of mechanical and chemical insults. This long-term exposure, combined with the normal reduction in tooth structure, sets the stage for more rapid and severe deterioration later in life.
Recognizing Severe Wear and Seeking Treatment
Common indicators of progressive tooth wear include increased sensitivity to hot, cold, or sweet temperatures. This sensitivity signals that the protective enamel layer is wearing thin and exposing the underlying dentin. Visually, teeth may appear shorter or flatter, or the edges of the front teeth may look thin, translucent, or chipped. Advanced wear may also cause the teeth to appear more yellow as the darker dentin becomes visible through the translucent enamel.
If these signs are present, a professional dental diagnosis is necessary to determine the root cause and pattern of the wear. Management strategies are always tailored to the specific cause, rather than just treating the damage itself. For wear caused by bruxism, a custom-fitted night guard is a common tool used to absorb the forces of clenching and grinding, protecting the teeth from further attrition.
In cases of erosion, the focus shifts to behavioral and medical changes, such as dietary counseling to reduce acid exposure and medical treatment for conditions like GERD. For teeth that have already suffered significant structural loss, restorative procedures may be required. These range from simple dental bonding to rebuild minor defects, to crowns or veneers for more advanced cases where extensive tooth structure has been lost.