Dental Assistant State Licensing Examination (DASLE) Practice Exam

The optimum level of fluoride in drinking water is recognized as 1 ppm (parts per million). This concentration has been established based on research that shows its effectiveness in reducing the incidence of dental caries (cavities) while minimizing the risk of dental fluorosis, a condition that can affect the appearance of teeth due to excessive fluoride intake during childhood when teeth are developing.

At 1 ppm, fluoride provides sufficient antimicrobial properties and enhances the remineralization process of teeth, safeguarding them against decay. This level balances the benefits of fluoride while avoiding the potential adverse effects that may occur at higher concentrations, such as dental fluorosis or other health concerns.

The other options reflect either too low or too high levels of fluoride. For instance, 0.5 ppm might not provide adequate protection against caries, while 2 ppm significantly exceeds the recommended limits and increases the risk of adverse effects. Similarly, 0.8 ppm, while closer to the desired range, is slightly below the optimum level recognized by health authorities. Therefore, 1 ppm is the scientifically supported level for maximizing dental health benefits from fluoride in drinking water.