Bulimia Nervosa (BN) is a serious eating disorder characterized by a cycle of binging followed by compensatory behaviors, most commonly self-induced vomiting or purging. This disorder causes significant dental problems because repeated exposure to highly acidic stomach contents is extremely damaging to the mouth. This chronic exposure rapidly breaks down the protective layers of the teeth, creating a distinct pattern of injury that dentists are often the first to recognize.
How Stomach Acid Damages Tooth Enamel
The primary mechanism of damage in Bulimia Nervosa is dental erosion, the chemical dissolution of the tooth structure by acid. Gastric acid, primarily hydrochloric acid, has an extremely low pH (often between 1.5 and 3.5), which is highly corrosive to the mineralized tissues of the tooth. When stomach contents are regurgitated, this powerful acid washes over the teeth, beginning the demineralization process.
The low pH environment dissolves the calcium and phosphate crystals that form the enamel, weakening the surface structure. This damage, specifically linked to regurgitation, is clinically termed perimylolysis. Perimylolysis typically presents as a smooth, rounded loss of structure, most noticeable on the lingual (tongue-facing) surfaces of the upper front teeth. The erosion pattern is often asymmetrical because the tongue usually provides a protective barrier for the lower teeth. As the enamel thins, the underlying dentin becomes exposed, which is softer and erodes at a faster rate.
When dentin is exposed, the teeth often appear more yellow or grayish, since the natural color of dentin shows through the translucent, damaged enamel. This loss of structure makes the teeth brittle and prone to chipping, fracturing, and increased sensitivity to temperature changes. Brushing immediately after a purging episode is counterproductive because the friction from the toothbrush further scrapes away the acid-softened enamel, accelerating the erosion.
Related Oral Health Issues Beyond Erosion
Bulimia Nervosa causes a range of secondary issues affecting the soft tissues and glands of the mouth, beyond enamel destruction. One notable sign is the non-inflammatory enlargement of the salivary glands, particularly the parotid glands, sometimes referred to as “chipmunk cheeks.” This swelling is thought to be a response to the constant stimulation and irritation caused by chronic vomiting and can be intermittent.
Chronic dry mouth, or xerostomia, is another frequent complication resulting from dehydration and electrolyte imbalances associated with purging. Saliva is the body’s natural defense against acid, helping to neutralize pH and remineralize enamel. A reduced salivary flow severely diminishes this protective function, compounding acid erosion damage and accelerating the risk of general tooth decay.
The combination of a reduced protective environment and consuming high-carbohydrate or sugary foods during binges significantly increases the risk of cavities. Cavities form rapidly, especially near the gum line where acid often pools and the enamel is compromised. The physical act of self-induced vomiting can also cause trauma to the mouth and throat, resulting in soft tissue lacerations, bruising, and small hemorrhages on the palate. A specific physical sign, known as Russell’s Sign, involves calluses or scrapes on the knuckles or the back of the hands from repeated contact with the front teeth when inducing the gag reflex.
Dental Strategies for Mitigation and Restoration
For patients currently struggling with Bulimia Nervosa, the immediate focus is on mitigation to prevent further damage until the underlying disorder is addressed. The most important action after a purging episode is to resist brushing the teeth, as friction causes irreversible mechanical wear on acid-softened enamel. Instead, individuals should immediately rinse the mouth thoroughly with plain water or a solution of water mixed with baking soda. Baking soda is alkaline and acts as a buffering agent, quickly neutralizing stomach acid. Dentists also recommend using fluoride rinses or high-fluoride toothpastes to promote remineralization and strengthen the remaining enamel structure. Once the bulimic behavior is controlled, restorative treatment can begin to repair lost tooth structure and address sensitivity.
Restorative Treatments
For minor erosion and hypersensitivity, dentists may use conservative treatments like bonding with composite resin to rebuild worn areas. Professional fluoride varnishes and desensitizing agents are applied to reduce discomfort. In cases of moderate to severe enamel loss, more comprehensive restorations are necessary.
- Porcelain veneers can cover the front surfaces of teeth, restoring shape, color, and strength.
- Dental crowns may be required for teeth with significant structural damage to protect the remaining material and restore proper function.
These dental interventions must be pursued in conjunction with professional treatment for the eating disorder, as restorative work cannot be successful long-term if the cycle of acid exposure continues.