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If you had your teeth straightened 50 years ago, instead of the brackets being cemented on
teeth, every tooth had bands around them. The arch wires were thick, and adjustments were
made by tightening the wires that held each tooth, the tooth moved, lessening the force to
practically nothing, and the patient went back to the orthodontist and did it all again. The
problem with this approach is that moving a tooth too rapidly kills it. Even if the
orthodontist was very careful, patients found that they had very sore mouths for several
days after they got their braces adjusted.
Through research using load cells, dentist have shown that mild pressure applied constantly
achieves faster and far more comfortable tooth movement with little danger to the actual
health of the tooth. One such study investigated using very light forces as measured by a very tiny load cell for tooth movement in rats. Another area of development in orthodontia has been new and improved bonding agents that
have allowed brackets to be glued onto each tooth rather than using the bands that
completely encircled each tooth. As a bonding agent cures, it contracts. This can be a
proglem because obviously greater contraction stress can adversely affect the bond strength,
which might lead to the tooth bracking popping off. Contraction stress as bonding agents
cure has been investigated with the use of load cells to determine the best bonding agent
for orthodontic use.
New materials such as the lightweight tooth moving wires developed through NASA, stronger
and lighter metals, and better bonding agents have changed the process of straightening
teeth. People find that todays high-tech materials are more comfortable, and there are many
new designs in orthodontic appliances and braces.
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