The aim of the study is to determine the fluoride availability in saliva and dental biofilm after the use of increasing amounts of fluoride toothpaste. Using a crossover and blind design, 15 children (18-42 months old) had their teeth brushed with increasing amounts of fluoride toothpaste. Fluoride concentration in saliva and dental biofilm was determined up to 30 min after brushing.

The aim of the study is to determine the fluoride availability in saliva and dental biofilm after the use of increasing amounts of fluoride toothpaste. Children from 18 to 42 months from a community daycare participated. The study had a crossover and blind design. The amounts of toothpastes tested were: 1. A pea-size amount (0.3 g) of a non-F toothpaste; 2. 0.025 g of a F toothpaste (1,100 ppm F, as NaF); 3. 0.05 g of the same F toothpaste; 4. 0.1 g of the same F toothpaste; or 5. 0.3 g (pea-size) of the same F toothpaste. Children were to brush their teeth with the designated amount of toothpaste twice/day from Monday to Friday. In order to allow biofilm accumulation, caregivers were instructed to brush only the occlusal surfaces of primary molars. On Friday morning, at least one hour after breakfast, saliva and one biofilm sample from the right or left hemiarch were collected and analyzed for fluoride concentration. Then, brushing with the respective amount of toothpaste was performed, and saliva was collected 5, 15 and 30 min later. The biofilm from the other side of the mouth was collected after 30 min. Fluoride concentration in saliva and biofilm samples was determined with an ion-specific electrode.

Inclusion Criteria:

• All children with an informed consent signed by the parents/guardians

Exclusion Criteria:

• Children with at least on active caries lesion