how long do you have to train to be a dentist
It takes 5 years at dental hospital to become a dentist and 2 years for hygienist. You can also do a combined course in dental therapy and hygiene which takes 27 months.Good luck.Source(s): Dental Nurse for last 10 years.eport Abuse. In the uk it takes about 5 years to train and qualify to become a dentist, and to become a dental hygeinist it takes 2 years both full time. Not sure how much it would cost to do dentistry, but i know the hygenist course at Kings College Hospital London costs Â£3,000 because i thought about doing it myself.