If teeth are so strong, why do they chip?

Tooth enamel is the hardest substance in the human body. It’s stronger than platinum, copper and gold. So why do we sometimes chip teeth on crackers, chips, nuts and other food? When I was 16, a Hershey’s Kiss (of all things) felled one of my lower molars, and my dentist told me that though teeth are strong, they can chip, crack or even shear (that’s what happened to me) with one misguided bite.

It was all a bit unnerving. My dentist soothed me by explaining it was rare, and in my case, the tooth was pretty healthy (glacial calving notwithstanding). He fixed the tooth and sent me home. Twenty-plus years later, I’m still baffled by the whole experience. I emailed Christina Byerson, D.D.S. (B.S.’09, D.D.S.’14), formerly in private practice and now an assistant professor of general dentistry at VCU, to learn more. …

This is a great question. And James is correct: Enamel, composed of calcium phosphate and arranged in a crystalized lattice, is the hardest substance in the human body.

However, it can only withstand so much pressure if excessive forces are concentrated in one small area. Chipped teeth are common — a typical dentist might treat hundreds in a given year. And while a Hershey’s Kiss is soft, there is a possibility the tooth was previously subjected to harder foods, parafunctional habits (such as clenching or grinding) or the tooth is in a state of demineralization (weakening of the enamel, most commonly caused by exposure to acids via foods and/or drinks or bacteria).

Let’s all do a quick self-assessment:

• While reading this article, are you clenching your jaw?
• Do you chew ice regularly?
• Has someone told you that you grind your teeth, or are you aware of clenching or grinding?
• In the past week, have you used your teeth to open items?

These are a few questions your dental provider might ask during a routine checkup. Eating hot foods quickly followed by a cold beverage can also expose teeth to rapid transitions of expanding and contracting, which can lead to microfractures. All these activities can weaken enamel, making teeth prone to chipping.

Practicing good oral hygiene prevents demineralization, while wearing a mouth guard during sports or physical activities, or a night guard fabricated by your dentist, can help reduce the risk of cracks and fractures. Regular dental checkups can also help identify and address potential weaknesses in your teeth before they become problematic. 

Finally, if you do chip a tooth, seeking prompt dental care can prevent further damage and ensure proper treatment to restore the tooth’s function and appearance.