Tooth enamel is known for its strength and flexibility- which is why researchers at the University of Michigan are using it as a model to build more resilient airplane flight computers. When in flight, airplanes are exposed to various vibrations caused by atmospheric pressure changes. These vibrations impact the solid structures of the airplane, and over time cause cracks and damage. Softer airplane structures have more flexibility to absorb the changes in pressure exerted on the plane, and do not suffer the same wear and tear as their more rigid counterparts.
The Michigan researchers examined tooth enamel samples from several species of animals- including a Tyrannosaurus Rex and a sea urchin. Their findings showed that while all of the animals had a different tooth structure, the structure of the enamel was the same. The fact that the enamel was the same led researchers to believe that enamel design had evolved the way it did in order to hold up to hold up to different levels of stress- as the Tyrannosaurus had a much different diet than humans.
"Tooth enamel is so durable because it has to last us through our entire lifetime," Dr. Steven P. Rogers, D.M.D, P.C., said.
Rogers is a Grant’s Pass, Oregon, dentist.
The average human lifespan is nearly 80 years. Humans are also born with all of their teeth, which erupt from the jaw over time. Although tooth enamel appears similar to bone in color and texture, its cells do not have the ability to repair itself.
"Tooth enamel does not regenerate," he said. "Taking care of your teeth to prevent decay and enamel erosion will help to reduce wear and damage to the tooth enamel."
Tooth enamel structure consists of ceramic crystals and a web of proteins covered in a hard, protective shell. This design allows teeth to absorb the vibrations caused by chewing and biting, and allows the force exerted on the teeth to be spread out through the structure and not exerted solely in one spot. In some teeth, this layer of crystals, proteins and protective shell is repeated.
"Some teeth are naturally designed to be stronger than others because of their designated function," Rogers said.
Teeth that are built stronger include the incisors and the molars as they are designed to tear into and chew through tough or hard foods.
The UM scientists recreated the structure of tooth enamel by using zinc oxide, a mineral, and plastic. They facilitated the growth of zinc oxide nanowires on a chip. Once the wires were grown, they added two plastic polymers over the nanowires, curing the plastic between coats. The process was repeated forty times to get one micrometer. One micrometer is one thousandth the width of tooth enamel. Once they reached one micrometer, they repeated the layer twenty more times. The project’s final result was an extremely durable material, that also had the flexibility needed to withstand atmospheric pressure needed to protect flight recorders in the air. This was confirmed through testing trials performed in conjunction with Michigan Technological University and the Illinois Applied Research Institute. The findings of the Michigan study will be published later this year in the journal, Nature, in the paper titled "Abiotic tooth enamel".
Rogers recommends that people brush and floss regularly to prevent tooth decay, and avoid highly acidic food and drinks that are known to damage and thin out tooth enamel.
"If you do consume a food or beverage high in acid, like orange juice or tomato sauce, taking time to brush right away helps to prevent that damaging acid from eating away at your enamel," he said.
University of Michigan. "Synthetic tooth enamel may lead to more resilient structures." ScienceDaily. ScienceDaily, 1 March 2017