Fluoride is effective in preventing cavities and tooth decay and in preventing plaque from building up and hardening on the tooth’s surface. A fluoride treatment in your dentist’s office takes just a few minutes. After the treatment, patients may be asked not to rinse, eat, or drink for at least 30 minutes in order to allow the teeth to absorb the fluoride. Depending on your oral health or your doctor’s recommendation, you may be required to have a fluoride treatment every three, six, or 12 months.