The paper by Aoba and Fejerskov written in 2002 talks about a hypothesized mechanism being a dose-related disruption of the mineralization which causes the teeth to become porous with a decrease in proteins. This degradation of the teeth is thought to be from a breakdown of the matrix proteins and the way the by-products are drawn out from the aging enamel (Aoba and Fejerskov, 2002). There are different forms categorizing the severity of enamel fluorosis. Mild enamel fluorosis is seen as white striations or opaque patches while in moderate or severe cases the opaque spots extend and the porosity increases (NRC Ch.6,1993). If the damage is severe enough there can be many dental health issues, including an increase in caries later in life. These …show more content…
99% of fluoride resides within the bones in different forms. One form is the fluoroapatite , which is how fluoride is incorporated into the crystalline structure of bone minerals. This form is suspected to actually make tissues stronger but has yet to be proven in human studies. With the tissues using the fluoride the bone requires more and more fluoride making the uptake to be the same or greater than its clearance rate (Turner, 1993). To investigate this clearance rate a mathematical model was created to fit the known pharmacokinetic data. The results of the Turner model predicts that fluoride clearance is four times longer than the uptake and that the uptake is positively associated with the bone remodeling rate (Turner,1993). With such a long clearance rate it makes sense that fluoride has a half-life of about 20 years once it is in the bone (NRC Ch.7,1993). While effecting the bone fluoride also effects the bone cells, osteoblasts, and functions. Fluoride stimulates osteoblast proliferation in humans and may lead to an increase in risk of osteosarcomas (Briancon and Meunier, 1981; Harrison,1981). Studies have been able to prove that fluoride does increase bone mineral density however it has also been noted that the bone strength becomes impaired. Similar to the teeth fluoride can effect bones by a disease called skeletal fluorosis. This disease is from excessive intake …show more content…
Animal studies of high quality were performed with a range of fluoride concentrations; these studies suggested that reproductive and developmental events are susceptible to disruption by fluoride. However in the animal studies concentrations of 250 mg/L (considered extremely high) were the only ones to produce adverse reproductive and developmental outcomes (NRC Ch.8,1993). Some of the reproductive hazards identified from the animal studies were: decreases in the amount of sperm and alterations to the epididymis and vas deferens (Kumar and Susheela,1991), effects on leydig cells and decrease testosterone (Narayana and Chinoy,1994), and decreased protein in the ovary and uterus with decreased activity of steroidogenic enzymes (Chinoy and Patel,2001). Human studies are limited due to the low amount of incident cases and the designs are problematic but a few studies suggest that fluoride in water at levels higher than 3 mg/L could be associated with alterations in reproductive hormones and fertility (NRC