The Anthropology Department wishes to congratulate Peter Lucas and Paul Constantino on the publication entitled "Remarkable Resilience of Teeth" in the April 2009 edition of the Proceedings of the National Academy of Sciences. Their research evolved through an interdisciplinary collaboration between anthropologists from The George Washington University and physical scientists from the National Institute of Standards and Technology in Gaithersburg, MD.
This research resulted in the discovery of several features in enamel--the outermost tooth tissue--that contribute to the resiliency of human teeth over a lifetime of chewing and biting. The research team found that the major reason why teeth do not break apart is due to the presence of tufts--small, crack-like defects found deep in the enamel. Tufts suppress the growth of these cracks in teeth by distributing the stress amongst themselves.
"This is the first time that enigmatic developmental features, such as enamel tufts, have been shown to have any significance in tooth function," said Constantino. "Crack growth is also hampered by the "basket weave" microstructure of enamel, and by a 'self-healing' process whereby organic material fills cracks extended from the tufts, which themselves also become closed by organic matter. This type of infilling bonds the opposing crack walls, which increases the amount of force required to extend the crack later on."
The team also studied tooth enamel in sea otters, mammals with teeth showing remarkable resemblances to those of humans.