It’s a common misconception that teeth are bones. It makes sense: both are white, hard, and contain calcium. If you think that teeth are bones, it’s no wonder why you’d be confused about why teeth can’t heal themselves the same way that bones can. However, similar as they may be, there are key differences between teeth and bones.
Why Aren’t Teeth Bones?
Both teeth and bones have calcium and are the hardest substances in your body. However, as similar as they appear to be, teeth and bones are actually made of different substances. While bones can regenerate and heal themselves, teeth can’t, which is why you can need fillings, root canals, crowns, and more.
What Are Bones Made Of?
Bones are made out of living tissue, with protein collagen and calcium phosphate. They also have marrow, which produces blood cells. Since bones are living tissue, this means that they’re constantly being regenerated and remodeled, similar to how your skin regenerates itself every 28 days. When old tissue is broken down, new tissue replaces it. This is why when you break a bone, it can heal itself.
What Are Teeth Made Of?
While bones are constantly remaking themselves, teeth can’t do this. This is because teeth aren’t made of living tissue. Rather, they’re made of enamel, dentin, cementum, and pulp. While teeth can undergo a process called remineralization, they can’t heal naturally. This is why if you have tooth decay, cracked teeth, or other types of tooth damage, it needs fillings and other types of dental treatments.
Why Don’t Teeth Regenerate?
Teeth and bones aren’t the same, however… There are animals that can indeed regenerate their teeth, similar to how bones can be regenerated.
Geckos regrow all of their teeth every 3-4 months, so they are constantly getting new sets of teeth. Sharks can have as many as 3000 teeth and lose about 100 a day. Horses don’t regrow their teeth, but their teeth are constantly growing, which is why horse owners need to have their horses floated every year or so (floating is when the teeth are ground down to a good length).
So, if in some animals, both teeth and bones can regrow or remodel themselves, why isn’t this the case in humans? Why do humans only get two sets of teeth in their lifetime, while the human skeleton completely remodels itself every 10 years?
Why Human Teeth Don’t Regenerate
You can thank evolution for the fact that humans only get two sets of teeth in their lifetime. The fact that teeth and bones are different and that our teeth don’t regenerate is actually something that was evolutionarily advantageous.
In short, it comes down to diet. The reason why creatures like geckos are constantly regrowing their teeth is because they need to. In order to catch and hold onto prey, their teeth need to be the same shape and size. In order to prevent wear and tear, their teeth just replace themselves.
Mammals have teeth adapted to their diets. For instance, horses are grazers. They’re constantly eating. Their teeth can naturally get ground down, so that’s why their teeth are constantly growing.
Humans have a diverse diet as omnivores. We need to be able to bite, cut, and grind with our teeth. In order to do this efficiently, your teeth need to match up. This is why dental problems like overbites and crossbites need correction. It is theorized that the reason why we only get our baby teeth and our adult teeth is to prevent the possibility of misalignment with regrown teeth.
Could Teeth Be Regrown In The Future?
If you’ve wished teeth and bones were more similar in how they can be regrown, this could be an option in the future. Scientists have used stem cells in order to help rats and mice regrow tooth tissue in damaged teeth. No human tests have been done yet, but in the future, there is the possibility that stem cells could be used to help restore damaged teeth tissue.
However, this is just a potential for the future. Since teeth and bones are different, if you have dental problems, you’ll need to see a dentist in order to have them fixed, lest you end up losing your tooth and needing to replace it with an implant. Teeth cannot heal naturally the way that bones can.