The hardest cell in the human body is enamel. It's the outer layer of our teeth and is composed of hydroxyapatite, a mineral that makes it incredibly strong and resistant to wear and tear.
Though enamel is incredibly hard, it's important to note that it is non-living and contains no nerves. This means it can't repair itself like other tissues in the body. Over time, enamel can degrade due to factors like acid erosion and bacteria.
