FLUORIDE CONCENTRATION IN DRINKING WATER SUPPLIES IN QOM, IRAN, AND DMFT INDEX OF 12-YEAR-OLD STUDENTS

The fluoride concentration in various drinking water resources of Qom province, Iran, and its relationship with the DMFT dental index of 12-year-old students was investigated. A total 270 samples were collected from different drinking water sources, which consist of drinking water systems relying on private, public and household desalination units. A total of 480 students 12 years of age were randomly selected from 24 primary schools with 20 students from each school. The entering criterion for each participant selected was at least 3 years of continuous consumption of each water source. Average fluoride concentrations in the water from the public saline distribution system (PSDS), the public desalinated distribution system (PDDS), private desalinated water suppliers (PDWS), and household desalinated water units (HDWU) were 0.45 mg/L, 0.16 mg/L, 0.1 mg/L, and 0.18 mg/L, respectively. The DMFT index of populations consuming water from PSDS, PDDS, PDWS, and HDWU was 3.1, 2.44, 2.8, and 1.99, respectively. Results reveal a direct relationship between fluoride concentrations of some resources (PSDS and HDWU) and DMFT index. Interestingly, the highest fluoride concentration (0.45 ppm) is associated with the highest DMFT (3.1), which is close to the DMFT (2.8) of the lowest fluoride concentration (0.1 ppm). It seems, therefore, that factors other than fluoride levels in the water, such as mouth rinse use, parent educational level, and tooth brushing frequency, have more important effects on the DMFT index. There were no obvious differences between DMFT among populations satisfied with PDDS and PDWS water. Consideration, however, should be given to water desalination systems during installation, operation, and maintenance regarding provision for by-pass lines to compensate for differences in desired fluoride concentrations. Because of the important effects of other factors besides fluoride, emphasis is recommended for parental educational programs regarding dental hygiene of their children.