When it comes to understanding tooth decay, a group of researchers is saying, "Leave it to beavers."
Researchers from Northwestern University have discovered something remarkable about the oral health of beavers, the semi-aquatic rodents that are known for their building skills and strong set of teeth.
These furry creatures certainly don't enjoy the same conveniences humans have as far as taking care of their oral health is concerned. But unlike us, they don't develop tooth decay.
The answer, it turns out, is the presence of iron in the enamel.
The enamel is one of the tissues that make up the teeth of humans and many animals including beavers. They are also the most visible parts-see the whites in your teeth?-and are made to be resistant to acids. Acid build-up happens based on the food a person eats. When there's too much acid, it "dissolves" the enamel, making the teeth more sensitive and at risk of developing cavities.
The main composition of enamel is hydroxylapatite, which looks like nanowires. Surrounding it are magnesium and iron, both amorphous minerals. When the enamel tries to protect the teeth from acid deterioration, it's not the nanowires that respond but these minerals. As the researchers put it, we do share a similar enamel structure but not composition with the beavers and perhaps other animals, and the difference in composition may help determine the degree of acid resistance of enamels.
In their study, the researchers looked into enamel of three animals including rabbits and beavers and analyzed the enamel's amorphous structure using tomography.
They then exposed the enamel to acid while taking before-and-after images, then noticed that the nanowires remained but the surrounding minerals dissolved. Subsequently the team analyzed how these minerals help in increasing the enamel's resistance and hardness and discovered that the incisors of beavers are pigmented and rich in iron, making it a much better enamel than one that's treated with fluoride.
With this knowledge, the research may be helpful in gaining a better understanding of oral health, especially how tooth decay develops.
The entire research is available in Frontiers in Psychology journal.