I think dental floss is really important.

I didn't really used to floss, but I went to the dentist for a check-up... haha

It turned out the part where two molars meet was slightly decayed. Unfortunately, it was right where they touch, and the dentist said that if they just ground down the cavity and put a crown on it, it might break later, so they had to dig out more than the cavity... Haha... It cost a little less than 2 million won.

Since then, I have truly realized the importance of dental floss and have been doing it every day.