Haisha Nante Kirai da!

Moriya Daiichi is a man who absolutely HATES dentists! After a very traumatic visit when he was young, Daiichi has done his best to brush and floss to the extreme so as to avoid a dreadful visit. While in college he receives a shock that has him neglecting his teeth and thus cavities formed. A friend forces him to finally make an appointment and Daiichi is then treated by the one and only Hara-sensei, an extremely young and handsome dentist whose only interest lies in well-kept teeth... And Daiichi's teeth are perfect!

Source: MAL