By 2040, more than one in four Europeans is expected to be over 65. Despite improvements in older patients' care, oral healthcare is still neglected. One of the major obstacles could be the negative representations associated with aging: ageism. The present study aims to quantify and qualify ageism for general and specific representations of aging associated with the mouth of an older patient compared to a young patient in dental students. Undergraduate students at the French dental school of Clermont-Ferrand were invited to participate in the study. Ageism was quantified by asking the students to estimate how many older adults have some negative conditions, which were then compared to real data. Representations of the mouth of a young vs. an older adult were collected by asking each student to write the first five words that came to their mind when they thought about the mouth of a young person and then the mouth of an older person. The students exhibited a large overestimation of health problems in the older adult population. The words given for a young adult were positive 49% of the time (vs. 23% negative), whereas 69% of the words were negative for an older adult (vs. 8% positive). The students in the second year were less negative than students in higher years. Our study contributes to assessing how dental students could exhibit implicit ageism. They show very negative representations of aging from the beginning of their training, which get even worse after they are exposed to clinical training with older patients.