8.23.16 in General
Healthy Mouth Sounds- Tooth Wear
What is the hardest material in the human body? If you answered enamel, you are correct.
Teeth are a marvel of engineering, especially considering the many things we use our teeth for. We bite, we chew, we rip, we tear, we speak, we smile, and yes, we even relieve the stresses of the 21st century using our teeth.
The tooth is made up of layers of different tissue types, each with its own function, strengths and weaknesses. Think of a tooth as a hollow “cylinder-like” structure. The part of tooth that anchors with ligaments to bone is called the root. Roots of teeth are made of cementum, which very closely resemble bone in its density. It is approximately 50% mineral (or inorganic). The second layer of tooth, just inside of the cementum and enamel is called dentin. Dentin is about 45% mineral content. The outer layer, above the bone and gum is called enamel, and enamel is 96% mineral. There is hardly any water or organic content in enamel at all. This makes enamel very dense, strong and smooth. What a great design! Inside the “hollow tube” is where the blood vessels and nerves that carries nutrients to the tooth, live. This is known as the pulp. The enamel actually is clear in color, and the “ivory” or yellowness of our teeth comes from the yellow dentin of the second layer of tooth shining through. Enamel is formed in rods, like the clear prisms in the Superman movie. But these rods are not layered flat on the surface, they actually stand on end. When we are looking at the smooth shiny “white” surface of our teeth, we are actually looking at the very tips of these hexagonal rods as they stand on end. This is significant to know when we try to explain how and why the hardest substance in the human body can wear. And also raises the question of –what can wear enamel?
Turns out, given our diets and habits, that the only thing we encounter that is hard enough to”abraid” enamel, is opposing enamel. That’s right. The most common form of tooth wear is called attrition, and it happens when teeth rub together. Not when we eat, not when we chew, but when we slide lower teeth across upper teeth. Attrition happens when we grind or “brux” our teeth. There are other types of tooth wear that we are going to talk about in the next blog. But we now have a great foundational understanding of the anatomy of a tooth, and should be able to illuminate how tooth wear occurs, and hopefully what to do about it.
So, stay tuned in and keep smiling. Dr W.