I don’t know specifically about dental hygiene but I suspect you should show how the things you have done/are doing over the past year or so, evidence the qualities or skills needed for the profession. For example have you worked in a public facing role or volunteered with vulnerable people to show you have experience of teamwork and can deal with/like interacting with people from a variety of backgrounds? Have you babysat, tutored younger pupils or run a session at your local brownies/scouts group to show you have an interest in teaching/educating? Are you an avid warhammer painter or embroiderer to show you have patience, care and an eye for detail? Etc