Analysis of fluoride levels retained intraorally or ingested following routine clinical applications of topical fluoride products

A variety of topical fluorides is now used clinically for the prevention an d control of dental caries. It is essential for the dental profession to be fully aware of the relative retention rates of fluoride in saliva and thus its contact with the teeth. These may vary following the use of the differ ent categories and concentrations of agents available and with different me thods of use. It is also important to be aware of the amounts of fluoride i on ingested following use of the more concentrated forms and of the resulta nt elevation in total blood fluoride levels. These parameters were investigated in a series of experiments involving hum an volunteer subjects using a variety of topical fluoride materials commerc ially available in Australia. Fluoride mouthrinses appeared to provide the highest salivary retention rates per dose of all forms of topical fluoride. Ingestion rates from concentrated gels were acceptable when effective evac uation methods were applied. The use of custom-made trays resulted in a red uction in amounts of fluoride ion ingested, though simple self-application by toothbrush of smaller quantities proved to be an effective alternative i n terms of amount of fluoride ion retained in saliva per amount applied and ingested. None of the concentrated gels used resulted in elevations in tot al blood fluoride levels which were of concern in adults. It is acknowledged that salivary retention rates of fluoride ion do not nec essarily reflect the caries inhibitory effects of topical fluorides, Howeve r, these data provide some indication of possible advantages of some produc ts and methods of application over others.