Tooth enamel: protection, loss, erosion, & repair

Tooth enamel is incredibly resilient but it can be damaged in an acidic environment produced by an abundance of bad bacteria, leading to tooth pain & decay. Learn how to protect & strengthen it.

You may have heard that enamel is the hardest substance in the body, but how much do you actually know about it? This article will help you to understand this oral superstructure!

What is enamel?

Enamel is the outermost covering of the part of your teeth that you usually see inside your mouth. It is made primarily of minerals including calcium and phosphate ions that are formed into prism-shaped rods^[6]. This mineralized material is referred to as hydroxyapatite. Enamel formation, also known as amelogenesis, is a very complex process that occurs in a special capsule inside the jaw bone. The process starts long before the teeth come in. Interruption of amelogenesis by high fever or other conditions can lead to defects in the enamel^[3].

Enamel Is essential for tooth health

Enamel is the protective layer that protects the more delicate inner layers of your teeth: the dentin and the pulp. Enamel provides the hearty structure necessary to crunch on almonds and crispy cookies without damaging your oral structures. It also protects against cavities because it is more resistant to acid and damage caused by plaque than other tooth structures^[6].

Acid and sugar damages enamel

Even though healthy enamel is very strong, it is still susceptible to damage from acid. The bad bacteria that live in your mouth secrete acid as a byproduct that dissolves the minerals in your enamel^[5]. This damage is known as demineralization. Bad bacteria thrive in an environment containing sugar and other simple carbohydrates. The more sugar present for the bacteria to feed on, the more acid is produced. Furthermore, higher acid production causes greater damage to enamel! All of this is the perfect storm for cavities to develop.

How to protect your enamel

Healthy eating habits and good oral hygiene are essential to keep your enamel healthy. Sugary foods and drinks should be consumed at mealtime, paired with other non-cavity forming foods such as meats and vegetables. If you want a sugary drink in between mealtimes, it’s best to limit the amount of time it takes to drink it—aim for 20 minutes or less.

Sipping on sugary drinks, or even sugar-free acidic drinks like diet soda, for a long period of time causes substantially more damage than drinking the beverage more quickly. This is because the oral pH is acidic for a prolonged period of time^[4].

Can damaged enamel be repaired?

Once enamel has been damaged by acid attack, there is hope for repair. However, this is only true if it is caught in early stages of damage. Demineralized enamel can be strengthened by exposure to fluoride. Fluoride actually binds to the enamel and strengthens it. Surprisingly, enamel that has been remineralized by fluoride exposure is stronger than enamel that was never demineralized in the first place^[2]! That is because the chemical makeup of the enamel has changed from hydroxyapatite to fluorapatite. Fluorapatite is very similar to the calcium and phosphate composition discussed above, except that it also contains fluoride ions, providing additional strength^[2]. Brushing your teeth twice daily with a fluoride toothpaste helps to strengthen the teeth, and the use of fluoride trays or other specialized treatments may be needed if you are at high risk for cavities^[1].

Rachel Stroble

Rachel Stroble is a researcher, professor of dental hygiene at Rose State College in Oklahoma, and registered dental hygienist with 10 years of experience in dentistry. She supports education in the classroom with her own students, in the professional community through the development and presentation of continuing education courses, and you may have seen her articles in RDH Magazine, Today’s RDH, and the Oklahoma Dental Association Journal.

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References

1. American Dental Association. (2021, July 15). Fluoride: Topical and systemic supplements. ADA. https://www.ada.org/resources/research/science-and-research-institute/oral-health-topics/fluoride-topical-and-systemic-supplements
2. Arifa, M. K., Ephraim, R., & Rajamani, T. (2019). Recent advances in dental hard tissue remineralization: A review of literature. International Journal of Clinical Pediatric Dentistry, 12(2), 139–144. https://doi.org/10.5005/jp-journals-10005-1603
3. Fatturi, A. L., Wambier, L. M., Chibinski, A. C., Assunção, L. R. da S., Brancher, J. A., Reis, A., & Souza, J. F. (2019). A systematic review and meta‐analysis of systemic exposure associated with molar incisor hypomineralization. Community Dentistry and Oral Epidemiology, 47(5), 407–415. https://doi.org/10.1111/cdoe.12467
4. Ireland, R., & Yeung, C. A., (2020) Stephan’s curve. In A Dictionary of Dentistry (2nd ed.). Oxford University Press.
5. Kulshrestha, S., Khan, S., Hasan, S., Khan, M. E., Misba, L., & Khan, A. U. (2015). Calcium fluoride nanoparticles induced suppression of Streptococcus mutans biofilm: An in vitro and in vivo approach. Applied Microbiology and Biotechnology, 100(4), 1901–1914.
6. Lacruz, R. S., Habelitz, S., Wright, J. T., & Paine, M. L. (2017). Dental enamel formation and implications for oral health and disease. Physiological Reviews, 97(3), 939–993. https://doi.org/10.1152/physrev.00030.2016