Either dentist or dentistry
Reservations in this context could mean doubts, such as 'My mom had reservations about going out to shop."
This means that their mom was not sure if she wanted to go shopping or not because she has reasons not to.
To write an application for a vacant post, make sure to write in a well professional manner. Include where you learned of the job vacancy and list the qualifications you have for the job. Finally, end in a professional, uplifting tone.
Are there any answers to this question?