Intraoral Transfer of Topically Applied Stannous Fluoride

¹ Miami Valley Laboratories, The Procter & Gamble Company, Cincinnati, Ohio

Chemical analytical determinations of fluoride and tin in whole rat teeth, bone, and human enamel showed conclusively that when the anticaries agent SnF₂ was applied topically to part of the dentition, significant amounts of fluoride and tin were transferred through saliva to the other quadrants. Part of this intraoral transfer did not occur immediately but proceeded over a period of 5-30 minutes after the topical application of the agent. For this reason it was concluded that an intraoral transfer of the treatment agent to the control side was practically unavoidable. Since it has been shown that the enamel of the untreated control quadrants has to be suspected of coming in contact with the ions of the treating solution, the main advantage of half-mouth studies is lost, that is, having control and treated quadrants in the same oral environment. The unwanted reduction in caries on the control half of the mouth will be the greater the more effective the applied agent is at low concentrations; thus, the differences between the treated and untreated side of the mouth will be minimized and the results distorted.