Ethos is a mode of persuasion that uses or mention a source or figure that shows or has credibility, expertise or prestige in order to convince an audience that the information is reliable, valid, and worth listening or paying attention to.
Ethos is what the sentence uses: It aims to persuade an audience that such toothpaste is the best options because it has dentists approval, who are professional that show credibility and expertise in that field.
