I recommend Wonju Apple Dental Clinic.

Even adults are hesitant and scared to visit the dentist. So I searched for a place I saw while passing by and went there. Just like the reviews said, the staff was incredibly kind and put my mind at ease. They explained everything thoroughly and made me feel good. The environment itself was bright and cheerful, which made it even more comfortable to go. I was also grateful that they did the scaling so well that it didn't hurt.