[Apollonia, patron saint of dentistry].

Apollonia's short trajectory and her martyrdom in the times of Emperor Decius in the 3rd century, is here reported. The artists who painted the saint are quoted, offering a small biography about their trajectory and principals works. Bernardino Luini, painting is studied with more detail, mentioning the similar characteristics of his Saint Apollonia with those of some of the personages painted by Leonardo da Vinci.