What makes teeth so hard? The hardest part of the tooth is the outer covering called enamel. It is made mostly of a chemical called calcium phosphate. This is different from the chemical that makes up ...

According to Cleveland Clinic, protecting your enamel will prevent the inner layers ... too hard or with specific dental ...

Anyone who's had braces may remember warnings about eating ... oranges and grapefruit are high in acid, which weakens enamel, especially with frequent and direct exposure.