Different fluoride compounds have been used in fluoride gels for years. Sodium fluoride can be used in a neutral pH environment or can be acidulated and buffered with a phosphate to form acidulated phosphate fluoride (APF). Clinical use of APF was developed in the 1960s, and the concentration commonly used in fluoride gel today is 1.23% (Newbrun, 2011). In the application, a sufficient amount of gel to cover the teeth in a dental arch is dispensed into a disposable tray and inserted into the mouth. The recommended application time is 4 min, and the patient should expectorate the gel afterward (Hawkins et al., 2003).