If you are serious about becoming a dental hygienist, you should start preparing for it from the 9th grade itself. You need to take biology, chemistry, and mathematics as your subjects for high school graduation. After that, you need to enroll at a dental hygiene school for an accredited dental hygiene program. Although some institutes do not mind admitting students who have completed high school diploma, others may insist upon at least 1 year of college studies. In that case, you might have to take a college entrance examination. Requirements for this profession include 4 years of formal education from a recognized school. This will enable you to apply for a job in research, education, clinical practice, etc. This bachelor's degree program is extensive with a syllabus including varied range of subjects like pathology, nutrition, chemistry, sociology, biology, English, and speech. However, if you are only interested in practicing in a dentist's office, then you may go for an associate's degree. Associate degree programs are offered by community colleges as well as technical colleges. Thus, it takes anywhere between 2 - 4 years, depending upon the option you choose, to fulfill the educational requirement for this profession.
After the successful completion of the program you need to obtain a license which will enable you to practice on your own, or at a dentist's office. Hence, the last hurdle in your course towards this profession is clearing an examination for obtaining the professional license.