Why is HF bad but sodium fluoride good in mouthwash?

Source: The Effect of 0.2% Sodium Fluoride Mouthwash in Prevention of Dental Caries According to the DMFT Index Just Because Fluoride has played a significant role in improvement of oral and dental health during the past 50 years. read more

When a fluoride rinse, also called a fluoride topical, is used fluoridethat stays in the mouth for about 30 minutes inhibits the formation of cavities and tooth decay. It can also strengthen the enamel of your teeth. After you brush your teeth, swish the fluoride rinse around in your mouth and then spit it. read more