Benzocaine is a commonly used local anesthetic which is the active ingredient in several over-the-counter numbers and anesthetic ointments such as Anbesol, Kank+a, Orabase B and Orajel due to its efficacy as a topical pain reliever. When combined with antipyrine, benzocaine can form A/B Otic Drops (sold as Auralgan) which are used to relieve earache and remove wax build-up. The drug works by acting as a chemical barrier, preventing sodium from entering free nerve endings and stimulating the nerve by causing depolarization resulting in an action potential.

Without these chemical signals, there is nothing for the brain to interpret as pain or any other sensation on the affected area. Allergic reactions occasionally occur, and in more serious cases methemoglobinemia can develop – a disorder which consists of elevated methemoglobin (oxidized hemoglobin that has very little affinity for oxygen) levels in the blood. This results in poor oxygenation of tissues, sometimes leading to hypoxia.

Fluoride is an essential mineral for healthy teeth which occurs naturally in water and many foods. As plaque builds on teeth during the day, minerals are lost form the tooth enamel and unless they are promptly replaced, tooth decay can occur. Fluoride can reverse early decay and makes teeth more resistant to acid damage. Children under the age of six also need a solid foundation of fluoride which is incorporated into permanent teeth. Nearly all toothpastes contain fluoride as do mouthwashes and tap water in most major cities (including New York). A stronger dosage is available via prescription from a doctor or dentist in the form of a tablet or an oral rinse. Dentists in particular can supply fluoride in the form of a gel, foam, or varnish applied directly to the teeth. Patients suffering from xerostomia, gum disease, or a history of frequent cavities can most benefit from additional fluoride, as can patients who have crowns, bridges, or braces.