Tooth enamel is the protective outer layer of a tooth, covering the visible portion known as the crown. As the hardest substance in the human body, its primary role is to protect the underlying dentin and pulp. This durable shield safeguards the sensitive inner parts of the tooth from the daily rigors of chewing and exposure to various substances.
Characteristics of Healthy Enamel
The hardness of enamel is due to its composition, which is about 96% mineral, primarily a crystalline form of calcium phosphate called hydroxyapatite. The tightly packed structure of these crystals gives enamel its strength, allowing it to withstand biting and chewing. While strong, this high mineral content also makes enamel somewhat brittle.
Healthy enamel has a smooth, glossy, and naturally translucent surface. The color of a tooth is determined by the dentin that lies just beneath the enamel. Functionally, enamel insulates the tooth, protecting the inner pulp and nerves from painful temperature changes caused by hot or cold foods and drinks.
Common Threats to Enamel Integrity
Enamel is vulnerable to two primary forms of degradation: chemical erosion and physical wear. Chemical erosion occurs when acids from dietary sources like sodas and citrus fruits, or from stomach acid, dissolve the enamel’s mineral structure. Frequent exposure to these acids can weaken the enamel surface over time.
Abrasion is the mechanical wearing away of the tooth surface, caused by using a hard-bristled toothbrush or brushing too aggressively. The friction from these actions can gradually remove thin layers of enamel.
Attrition results from tooth-to-tooth contact, which is associated with bruxism, a condition where a person habitually grinds or clenches their teeth. The constant pressure and friction from grinding can wear down the chewing surfaces of the teeth, leading to enamel loss.
Methods for Enamel Preservation
Protecting enamel involves mindful dietary habits, starting with limiting acidic foods and beverages. When you consume acidic items, rinse your mouth with water afterward to help neutralize the acids. It is also advisable to wait at least 30 minutes after acid exposure before brushing to allow saliva to reharden the softened enamel.
Proper oral hygiene tools and techniques are important. A soft-bristled toothbrush is recommended to prevent abrasion, along with gentle brushing. Using a fluoride toothpaste is also a standard recommendation for daily care.
Fluoride is a mineral that strengthens enamel. It integrates into the enamel’s hydroxyapatite crystals to form a more acid-resistant compound called fluorapatite. This process, known as remineralization, helps repair enamel weakened by minor acid attacks. For individuals at higher risk of decay, a dentist might suggest professional fluoride treatments to further bolster the enamel’s defenses.
Signs of Enamel Damage and Repair
The initial sign of enamel loss is often tooth sensitivity. As the enamel thins, it can no longer effectively insulate the underlying dentin. This results in discomfort when consuming hot, cold, or sweet foods and drinks.
Another visible sign is a change in tooth color. As the translucent enamel wears away, more of the yellowish dentin underneath becomes exposed, causing the teeth to appear discolored. Advanced enamel loss can lead to more significant structural problems, such as increased susceptibility to chips and cracks.
While the early stages of demineralization can be reversed through remineralization with fluoride, significant enamel loss is permanent. The body cannot regrow lost enamel tissue. For substantial damage, dentists may recommend restorative procedures like dental bonding or veneers to restore the tooth’s appearance and function.