Fluoride is one of the 14 necessary elements for animal life that exists in a measurable quantity in the tissues and liquids of the man's body and has been in the microelements category from the aspect of the mineral material that man only needs a few milligrams daily.
The tooth decay decrease ability is an important helpful effect physiologic if Fluoride, thus it can be pretension that the main cause of the tooth decay is a deficit of the Fluorine compounds in the body, for this reason, and prevention of the DMF increase, the drinkable water must be fluorination, with due attention to that excessive fluorination cause fluorosis, brownish spots permissible fluoride in the drinkable water is depended to the water temperature. Thus, at the duration of the week, month, seasons, and year it must increase (if the Fluorine concentration is more than the upper limit, it will decrease.), furthermore, because it is changeable from minimum to maximum, it requests high accuracy.
In this study that took place 12 months, 2176 samples from 33 deep wells ( origin drinkable water ) and 2 service reservoirs and different places of water distribution network, were directly collected, then with SPANDS  method and by the spectrophotometer had been determined the concentration of daily, weekly, monthly and seasonally fluoride.
The results indicated that the quality of the water in all sources have been undesirable at the year of this study accomplished.
The fluoride annually average concentration in the measured samples was 0.561 milligram in a liter (PPM), and neither of the sources with due attention to fluoride concentration minimum has not to the condition of lower F.Conc. Thus it is not an expectation the increase DMF because if it is not securing the optimum quantity of Fluoride in the drinkable water, it must compensate for this deficit in other ways.