Caries Preventive Effect of Salt Fluoridation in Preschool Children in The Gambia

Patients and Methods This was a block-randomized, controlled, open-label trial to evaluate the relative caries preventive effect of fluoridated table salt in communal feeding of preschool children after 12 months. The study protocol was approved by the Witten/Herdecke University institutional review board (No. 106/2010) and by the Department of State for Health and Social Welfare of the Republic of The Gambia in the form of a memorandum of understanding. All participants and parents or legal guardians gave written informed consent with the aid of a native speaker before study-related procedures were performed and the study was conducted in line with the Declaration of Helsinki. Figure 1 describes the study design in brief.

Sample Size Sample size calculation was performed with G*Power 3. Basic data for sample size calculation was the mean dental caries experience of preschool children in urban parts of The Gambia that was reported to be 2.09 dmft teeth (SD: 1.92). An effect measure of caries prevention by fluoridated table salt of 35 % was assumed according to the relevant literature. Alpha error was set with 0.05, and the study power with 80 %. A target sample of 130 subjects for each study arm (test and control group) was calculated.

Study Population

Eligible participants were children aged from 3 - 5 years living in urban Gambia with preschool attendance at the co-operating kindergartens. The inclusion criteria for participating in this study were:

1. a complete primary dentition
2. parental or legal guardian informed consent. The only exclusion criteria was refusal to participate in the study. Study End Points To measure the caries preventive effect of salt fluoridation (1) the difference of incidence of cavitated carious lesions (Δd3/4mft) after study related intervention was chosen as the primary end point. Using the primary study end point, the relative preventive dental caries effect was calculated according to the following formula: 100 - (Δd3/4mft (test group) / Δd3/4mft (control group)) x 100.