Distribution and retention of salivary fluoride from a sodium fluoride tablet following various intra-oral dissolution methods.

The distribution and retention of salivary fluoride were investigated according to the following intra-oral dissolution methods of a sodium fluoride tablet: active chewing/swishing, active sucking/swishing, and passive dissolution in the maxillary and mandibular labial vestibule. The results suggested that the oral cavity was somewhat compartmentalized, in that homogeneous distribution of a dissolved fluoride tablet did not occur throughout the mouth, but rather each site sampled was influenced by various rates of clearance and retention. Tablet chewing may have an advantage over tablet sucking in terms of salivary fluoride retention, and there was a tendency for fluoride to be preferentially retained in the maxillary labial vestibule following swishing. The passive tablet dissolution methods resulted in a less homogeneous distribution of fluoride. Although the fluoride retention values for passive dissolution were impressively superior to either active dissolution method, the alarmingly high salivary fluoride concentrations (4000 ppm F) recorded at the passive dissolution sites should discourage its use until the potential cytotoxicity of this approach is thoroughly investigated.