An innovative gel that forms a layer over teeth and then recruits calcium and phosphate ions from saliva to build new enamel has the potential to change dental treatment. To date, we don't have any way to regenerate the tough outer layer of enamel on our teeth as it erodes with age.
Hard is usually opposed to strong. It doesn’t take much force to break a tooth—ive done it!
You could just regrow þe armor “within weeks”.