The story about artificial teeth/dentures
Artificial teeth/dentures were used by Egyptian and South American in the old days. They are made by elephants' tusks, wood, or shells. Now, artificial teeth/dentures are improved their quantity at the high level of strong and enduring natural teeth.
When a tooth is extracted, the remaining teeth next to and opposite it have the risk of disproportion. Losing a tooth can lead to the loss of other teeth, which can decrease the chewing function of jaws or can make other teeth decayed.
Replacing the lost teeth by putting a thing deep inside jaw-bones is not a strange thing. Archaeology shows that Egyptians and South American in the old days replaced the natural teeth which are lost by elephants' tusks, shells or wood. In the 18 th century, the medicine recorded some cases of implants of givers.
When medicine began to use officially artificial teeth/dentures, the replacing parts mostly are made by plastic. The strong points are cheap, beautiful color, fast recovery time. But the weak points are easily oxidized, worn out, broken, and change color.
Then, people liked to change into the artificial teeth/dentures made by metal. Be strong, have ability of suffering the high strength, less deformation, easily using were their good points. But teeth had the color of mental so that aesthetic feature was low, it was difficult to make teeth clean, and their prices were high.
After a long time, people who did not have the beautiful teeth required their dentists to build for them the artificial teeth/dentures by porcelain. Porcelain had the high level of strength, was less worn out, and could be used for a long time. This kind of artificial teeth/dentures looked like natural. They did not change color; absorb saliva so that it cannot make them have a strong breath. At that time and until now, porcelain is considered the most preeminent material.
During a long time, methods of treatment for people having lost teeth are to use bridges and artificial jaws. In order to supply the stand for artificial teeth/dentures, when the dentists make the bridges, they have to grind other healthy teeth beside them, which can make them died of marrow, decrease their expectation of life. If they make the artificial jaws, they will suffer the feeling of being tangled in, being unpleasant, even being painful, difficulty in chewing. The artificial jaws are not totally fixed. They can make people wearing them pronounce wrongly. Keeping them clean is also rather the complicated thing.
Recently, the dentists have applied a modern technology named "Dental implant". This method is popular immediately. A small titan pin will be used instead of the roots of teeth which are lost. After injection of desensitizer, the dentists will put slightly the pins into jaw-bones without causing any hurt to the patients.
When the organization of jaw-bones seizes the titan pins, these pins will become firm, even firmer than the roots of natural teeth. At that time, the dentists will put above titan pins the artificial teeth/dentures which are decorated conformity with the teeth of each person.
The best point of dental implant is that it does not cause any harm to surrounding teeth. Thanks to putting directly above titan pins, the artificial teeth/dentures will stand independently in the jaws. They do not need to lean on other healthy teeth beside them. Because of not being worn out, the new teeth can be maintained maximum.
With implant, you can use the chewing function as natural teeth. The hygiene of teeth should be improved sharply because tooth brushes can touch "the new soldier" easily. If you know how to keep them clean in right ways and regularly, the implant teeth can be kept forever.
The children of rich families have the high risks of cancer
In recent research, the UK scientists have found out that the proofs which caused white blood cells, and other cancer in children (such as blood cancer, bone cancer, and other parts of the bodies) could relate to the richness.
They believed that there was an explanation based on "the theory of dirtiness". According to the theory, children grew up in too clean environment and they seldom contact with outside environment, which can make their immune systems decline. It is considered to be the combined reason causing to increase the rate of children having asthma. To crowded places, children have to contact with virus more often and become immune from them.
Before there was a research claiming that allowing children in the first months to go to the kindergartens can decrease a half of the risks of having white blood cells because they can communicate early with some types of affected virus.
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