Enamel is made of minerals, and when it's damaged, it cannot repair itself the same way other parts of the body can. Applying fluoride and other remineralizing substances, however, can strengthen weak enamel and prevent cavities as long as there is enough enamel left over.
Tooth enamel restoration doesn't come naturally, which is why your dentist can replace weakened parts of your teeth so you can use them the normally. Here's how.
Where Enamel (Doesn't) Live
A tooth is made of living and nonliving parts. The pulp at the center of the tooth is living, contains blood and nerves and is sensitive to pain. Outside the pulp lies dentin, also living, and appearing as a brown and porous material just beneath the enamel. Dentin makes up most of the tooth.
Covering the dentin is your tooth enamel, the hardest substance in the body. Tooth enamel is nonliving, primarily made of calcium phosphate (among other minerals) and arranged in a crystal structure called hydroxyapatite.
How Enamel Forms
Tooth enamel forms in the gum before the teeth emerge. According to the University of California San Francisco, cells called ameloblasts create tooth enamel by producing specialized proteins. When these ameloblasts have done their work, they disappear, and the enamel stops growing. Fully developed tooth enamel contains nearly no ameloblasts or other living material.
How Tooth Enamel is Lost
Tooth enamel loses minerals, weakens and breaks down in stages. It starts when the acids in your food, drink and even your mouth's natural bacteria gradually dissolve its calcium phosphate through a process called demineralization. Demineralized teeth sometimes look yellow because the enamel is thin and the brown dentin shows through more easily.
Brushing twice a day for two minutes with a fluoride toothpaste helps prevent this demineralization, but does not always stop the process. If the tooth enamel is weak but hasn't broken down, however, fluoridated tooth enamel restoration treatments containing calcium phosphate can replace the lost minerals and return the enamel to its original strength. Some over-the-counter toothpastes, like Colgate® Enamel Health™ Sensitivity Relief, contain sodium fluroide to help remineralize enamel in this way. Similar high-fluoride remineralizing gels, toothpastes and treatments are available through prescription from your dentist – always feel free to ask.
Why It's Not Always Saved
When demineralized enamel continues to lose its minerals, it is eventually destroyed. The dentin beneath it is left unprotected and a cavity forms, usually causing sensitivity and sometimes an infection. Applying remineralizing treatments at this stage does not restore the destroyed enamel, but it does strengthen the remaining enamel before it goes away. A dentist can repair a cavity by filling it, but cannot restore the enamel itself.
Tooth enamel plays one of the most important roles in preventing cavities, so it is well worth protecting. Healthy enamel also looks more attractive than weak, demineralized enamel. Look after the enamel on your teeth, so that when it's gone, you can use the rest to restore your smile.