If you are like me, you brush your teeth—too vigorously, I’m told—with a plastic rack of plastic bristles. You use your plastic brush to lather a paste pushed from a plastic tube. When you have a cavity, you go to a dentist who might fill the hole with a plastic composite then sand it flush...

Ever watch Cameron Norrie grinding it out on the tennis court? The British lefty just had a tough loss to Roberto Bautista Agut in straight sets at the Cincinnati Open, but hey, every athlete has those days. What’s really interesting, though, is what happens when he steps off the court.