Today, several alternatives for fluoride therapy are available. To give advice on the choice of method, the dentist should have information on how effective different fluoride treatments are in increasing salivary fluoride concentration. The aim of the present study was to measure the fluoride concentration of saliva after the use of four different fluoride methods commonly used in the Nordic countries: F mouthrinse (0.023% F), F toothpaste (1.1% F). F lozenge (0.25 mg F), and F chewing gum (0.25 mg F). In addition, a new method using toothpaste water mixture as a mouthrinse was included in the study. Fourteen adult volunteers used each of the five methods on separate days. Unstimulated saliva samples were collected at base line and 0, 10, 20, 30, 45, and 60 min after the fluoride procedure. Fluoride was separated by the microdiffusion method and analyzed using a fluoride-specific electrode. Fluoride mouthrinse and fluoride toothpaste increased the fluoride concentration of saliva significantly more than fluoride lozenge and fluoride chewing gum. For both of the latter, salivary fluoride concentration was still increased after 1 h. Toothpaste-water rinse was more effective than brushing with toothpaste. Rinsing with toothpaste-water mixture appears a good alternative for adults who need extra fluoride therapy but are not motivated enough to brush their teeth several times a day.

Glass ionomer fillings have been suggested to act as a fluoride-releasing system in the mouth. The aim of the present study was to evaluate whether a glass ionomer slab applied on the enamel can increase the fluoride content of the enamel and plaque of adjacent teeth in real-life conditions with frequent exposure to fluoride from other sources. Twenty-five adults living in a town with fluoridated drinking water participated in the study. The initial enamel fluoride content on the buccal surface of the contralateral premolars was determined using the acid etch biopsy technique. A round glass ionomer slab was placed buccally on the first molar on a randomly chosen side of the mouth (test side). After 2 weeks, the enamel fluoride content of premolars on the test and control sides was again determined whilst avoiding the site of the first biopsy. In addition, one biopsy was made on a previously etched area. After 2 and 4 weeks, plaque was collected from three approximal surfaces both on the test and control side, and the total fluoride content of the plaque was analysed. There were no significant differences in the fluoride content of sound or etched enamel before and after placement of glass ionomer. The fluoride content of approximal plaque of teeth close to glass ionomer was not higher than that of the control teeth, either after 2 or 4 weeks. Using the present method, no increase in the fluoride level of teeth adjacent to glass ionomer could be demonstrated. This may be due to the masking effect of fluoride from other sources.