Teeth (July 19)
Teeth are surprisingly tough; we can bite and chew food for decades without cracking. A tooth’s dentine is covered with tooth enamel. How can enamel, which by itself is brittle like glass, survive our chewing and biting process without cracking? Researchers have found that the design of the tooth enamel prevents cracks in three ways:
- Tufts are crack-like flaws deep within the tooth where the enamel and dentine meet. Under the stress of biting or chewing, these tufts distribute the stress – suppressing the growth of cracks.
- Enamel is made up of rods that criss-cross each other like basket weave. This hinders cracks from spreading.
- If a crack expands, the tooth fills in the space with material extended from the tufts – which glues the cracked walls and stops further expansion.
Our teeth are extremely tough structures built from brittle materials – yet, they are able to withstand a lifetime of biting and chewing because of their design. When we see a design, we know there must be a designer. The tooth’s designer is Jesus.