Every morning when my mirror smiles back, I am grateful to two dentists who have helped me for decades.

They must be darn good, because thanks to regular visits I’ve retained excellent cuspids, bicuspids, plus a host of workable molars.

I am not the best patient. I nearly always brush my teeth at least once a day, and sometimes use toothpaste.

But I am an excellent flosser. I know this, because th...