Most people use toothbrushes, toothpaste and dental floss to clean their teeth, but their use is by no means universal. Many indigenous groups, as well as people in developing countries, use traditional techniques to clean their teeth. Some of these techniques are more effective than others.
원문출처 : https://www.cnn.com/2019/07/09/health/alternative-ways-to-clean-teeth-partner/index.html
원문출처 : https://www.cnn.com/2019/07/09/health/alternative-ways-to-clean-teeth-partner/index.html