Iontophoresis is a noninvasive method to enhance systemic and local drug delivery by the application of an electric field. For systemic drug delivery in the oral cavity, iontophoresis was studied primarily for transbuccal delivery. Significant enhancement of drug delivery was observed in buccal iontophoresis compared to passive transport for different drugs. For local drug delivery in the oral cavity, iontophoresis could enhance drug penetration into the enamel, dentin, and other oral tissues for the treatment of oral diseases. Iontophoresis was evaluated in dentistry such as to produce local anesthesia and treat tooth decalcification and hypersensitivity, but this technology has not been fully utilized. The most common drugs in these evaluations were fluoride and lidocaine. In general, there is limited knowledge of the mechanisms of iontophoresis in the oral tissues. In vivo animal and human studies have suggested that iontophoresis is safe in the oral cavity under the conditions investigated. The present review covers the topics of iontophoretic drug delivery in the oral cavity for both systemic and local treatments. The anatomy and diseases in the oral cavity for iontophoretic drug delivery are also briefly reviewed, and the challenges for this drug delivery method are discussed.
Keywords: buccal; dentin; drug delivery; enamel; gingiva; iontophoresis; oral cavity; palate; transport.