dentista
(n.) (fem./masc.) (sing.)
dentist
There are nouns with endings that do not change according to the gender, such as "portavoz" (spokesperson) and "recepcionista" (receptionist). With these nouns, the gender of the particular person/item is indicated by the article and/or adjectives which may accompany it. La portavoz; el portavoz, una recepcionista, un recepcionista.