dental fluorosis
Introduction
Introduction to dental fluorosis Fluorosis is also known as dental plaque or mottledenamel, which is regional and is the most common and prominent symptom in the early stages of chronic fluorosis. Fluorosis has been reported in all countries of the world. There are many epidemic areas of fluorosis in China. There are chronic fluorosis areas in Northeast China, Inner Mongolia, Ningxia, Shaanxi, Shanxi, Gansu, Hebei, Shandong, Guizhou and Fujian. Fluorosis is related to people's health, and severe cases of fluorosis at the same time should be highly valued. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: diarrhea
Cause
Cause of fluorosis
Eating habits (30%):
The optimum concentration of water and fluorine mainly depends on the local average maximum temperature. The United States is 0.7-1.2ppm; Guangzhou is about 0.7ppm. China has a vast territory, and the temperature difference between the north and the south is very large. Therefore, there is not only one suitable concentration, so the current water quality in China. A standard fluorine concentration of 0.5 to 1 ppm should be suitable.
The absorption of fluoride in food depends on the solubility of inorganic fluoride in food and the content of calcium. If calcium is added, the absorption of fluorine is significantly reduced. Animal experiments have confirmed: adequate vitamin A, D and proper amount of calcium. Phosphorus can reduce the damage of fluorine to the body. This indicates that the high fluorine content is not the only cause of fluorosis, because the area with slightly higher fluoride content in water is not everyone suffering from this disease.
Excessive fluorine absorption (30%):
When multi-fluorine enters the human body, fluorine mainly damages the enamel cells of the tooth germ during enamel development. Therefore, excessive fluoride can only enter the body during the mineralization of the teeth, and fluorosis can occur, if it is before the age of 6 or 7 Long-term living in the epidemic area with high fluoride content in drinking water, even if you move to other places in the future, you can't avoid the permanent teeth that are erupted later. On the contrary, if you move into the high fluoride area after 7 years old, there is no fluorosis. .
Dysplasia (30%):
Excessive fluoride affects the developing ameloblasts, which changes the cell function; fluoride affects the enamel matrix, reduces the activity of the enamel proteolytic enzyme, and retains the enamel protein, which indirectly affects the formation of enamel crystals. In addition, fluorine can directly affect the formation of enamel crystals. The mineralization of enamel is the formation of hydroxyapatite crystals on the enamel matrix by inorganic calcium and phosphorus. Once the pyrophosphate in the body fluid occupies the phosphate position on the crystal lattice, the enamel mineralization stops. Alkaline phosphatase can hydrolyze pyrophosphate to ensure normal enamel mineralization. When the local fluoride concentration is increased, the activity of alkaline phosphatase is inhibited, and the concentration of pyrophosphate is increased, thereby causing enamel dysplasia and incomplete mineralization.
It is well known that alkaline phosphatase can hydrolyze various phosphonates and provide inorganic phosphorus in bone and tooth metabolism as a raw material for bone salt formation. When the concentration of fluorine is increased, the activity of alkaline phosphatase can be inhibited, and bone diseases such as enamel dysplasia, mineralization incompleteness and bone brittleness are caused, resulting in poor interstitial mineralization and excessive mineralization of the glaze column. In this case, the enamel of the surface layer is more remarkable, and the surface enamel has a fluorine content of about 10 times that of the deep enamel. Therefore, the surface enamel of fluorosis is porous, and it is easy to adsorb foreign pigments such as manganese and iron compounds to produce fluorine spots. The amount of micropores in severe fluorosis can reach 10% to 25%. Located between the glaze columns and distributed along the horizontal stripes. If the porosity of this porosity is large, the surface of the enamel will collapse and the fossil enamel will be incompletely developed.
Prevention
Fluorosis prevention
(1) To prevent industrial pollution, the harmful fluorides produced in the industrial production process must be treated harmlessly, protect the environment, and even be transferred to benefit for the benefit of mankind. For example, the fluoride added by the Guangzhou Waterworks is a fluorosilicic acid or sodium fluorosilicate recovered from the harmless treatment of the waste gas of the phosphate fertilizer plant. (2) Change the water to change the stove, improve the water quality can use the method of changing the water source and reducing the fluorine content of the drinking water. Changing the water source is to abandon the original high-fluoride water source and look for a water source with low fluorine content. Reducing the fluoride content of drinking water means using certain chemicals or physical methods to reduce the concentration of water in the water source.
Complication
Fluorosis complications Complications, diarrhea
Severe chronic fluorosis patients may have proliferative changes in the bones, periosteum, ligaments, etc. can be calcified, and thus produce waist, leg and systemic joint symptoms, acute poisoning symptoms are nausea, vomiting, diarrhea, etc., due to blood calcium and fluoride Combined, the formation of insoluble calcium fluoride, causing tendon, collapse and difficulty breathing, resulting in death.
Symptom
Symptoms of fluorosis Common symptoms Teeth whitening to the teeth... Diarrhea, nausea, nausea, yellowish gray...
1. The clinical manifestation of fluorosis is characterized by white ochre to brown plaque on the enamel erupted in the same period. In severe cases, there is a enamel substantial defect. It is often divided into white sputum according to its light, medium and severe. Type (mild), colored (moderate) and defective (severe) three types.
2. It is more common in permanent teeth. It occurs in deciduous teeth and is mild. This is because the occurrence of deciduous teeth is in the embryonic stage and the infant stage, respectively, and the placenta has a certain barrier effect on fluoride. Therefore, fluorosis is generally They are all found in permanent teeth, but if the fluoride intake is too much, beyond the limit of the screening function, it can also be expressed irregularly on the deciduous teeth.
3. Poor resistance to friction, but strong resistance to acid etching.
4. Severe chronic fluorosis patients may have proliferative changes in bones, periosteum, ligaments, etc. can be calcified, and thus produce waist, leg and systemic joint symptoms, acute poisoning symptoms are nausea, vomiting, diarrhea, etc., due to blood calcium Combined with fluorine, it forms insoluble calcium fluoride, causing tendon, collapse and difficulty breathing, leading to death.
Examine
Fluorosis examination
Combined with medical history, oral examination and examination of tooth surface staining and defect. In the same period, the enamel erupted from the enamel to the brown plaque, and in severe cases, there was a substantial defect in the enamel. Clinically, it is divided into three types according to its light, medium and severe degrees: white (mild), discolored (moderate) and defective (severe):
(1) White sputum type (mild) The tooth surface loses its normal luster and opaque plaque appears;
(2) Discoloration type (moderate) The tooth surface appears yellow, yellowish brown or tan;
(3) Defective type (severe) In addition to the above changes, the tooth surface also has a shallow pit or a pit-shaped defect, or the tooth loses its normal shape due to wear.
These three manifestations can be divided into the area affected by the tooth surface: mildness is <1/3; moderate is l/2~2/3; severe is all tooth surface.
Diagnosis
Diagnosis and diagnosis of dental fluorosis
This disease should be distinguished from enamel hypoplasia.
1. The enamel dysplasia has a clear perimeter, and its ridges are in parallel with the enamel growth line; fluorosis is a long-term injury, so its plaques are scattered in the cloud, and the perimeter is not Clear and not consistent with the growth line.
2. Enamel hypoplasia can occur in a single tooth or a group of teeth; and fluorosis occurs in most teeth, especially in the upper jaw.
3. Patients with fluorosis can have a life history in the high fluoride area.
