It can sometimes be surprising where we end up learning details about how something works. We were surprised about the recent research on enamel that was developed by understanding why beavers have strong teeth.
Exploring why beavers have a natural tooth decay fighter is allowing researchers at Northwestern University to better understand our own enamel. It turns out it is all about the iron when it comes to making the beaver teeth enamel harder and more acid resistant than most enamel, even enamel that has been treated with fluoride.
How enamel works is more complicated than one may initially realize. A team led by Derk Joester discovered a part of enamel that stores amorphous (unstructured) minerals rich in magnesium and iron that control the mechanical properties and the acid resistance of the enamel.
“We have made a really big step forward in understanding the composition and structure of enamel — the tooth’s protective outer layer — at the smallest length scales,” said Joester, associate professor of materials science and engineering in Northwestern’s McCormick School of Engineering and Applied Science and lead of the study.
“The unstructured material, which makes up only a small fraction of enamel, likely plays a role in tooth decay,” Joester said. “We found it is the minority ions — the ones that provide diversity — that really make the difference in protection. In regular enamel, it’s magnesium, and in the pigmented enamel of beaver and other rodents, it’s iron.”
This study is a first of its kind looking at this level of enamel.
Tooth decay involves dental caries which is when the enamel erodes due to bacteria. In Latin, carries means “rottenness” and the its presence in a large percentage of adults’ mouths makes it the most common chronic disease as well as considered a significant public health problem that continues even though fluoride treatments have been used.
As the World Health Organization reminds us, It is estimated that 60 – 90 percent of children have tooth decay issues, and quite close to 100 percents of adults through the nation have or have had cavities. This brings an estimated annual dental service spending to over $100 billion.
A variety of animals were studied to identify the advantages of their enamel, including mice, rabbits, rats, and beavers. The research team experimented with the enamel of a variety of animals including rabbit, mouse, rat and beavers. By placing acid on the teeth and comparing before and after photographs, the research team was able to identify the sources of strength in the enamel and determined it to be the presence of iron and magnesium.
“A beaver’s teeth are chemically different from our teeth, not structurally different,” Joester said. “Biology has shown us a way to improve on our enamel.”
Joester and his team are hopeful the research will help in enhanced fluoride treatments or other ways to increase the strength of human enamel. As our oral health improves, we may have the beaver and it’s hefty front teeth to thank.
Changing Lives, One Smile at a Time
Dr. Randall Burba is an AACD accredited dentist, practicing in Salem, MA. He considers himself an artist – with teeth and beyond! He often paints, draws and has a passion for woodworking. Follow Burba Dental Partners on Twitter and Facebook.