| Did You Know...
The major causes of tooth loss in people under the
age of 35 are sports, accidents and fights.
George Washington's dentures were made from walrus,
hippopotamus, and cow's teeth, as well as elephant tusks.
In 200 AD, the Romans used a mixture of bones, eggshells,
oyster shells and honey to clean their teeth.
The second most common disease in the United States
is tooth decay. The first is the common cold.
How much is the Tooth Fairy paying per tooth? Around
$2 per tooth, according to Securian Dental Plans, an insurance provider.
An average American spends 38.5 total days brushing
teeth over a lifetime.
Commercial floss was first manufactured in 1882, but
Egyptians invented the first toothpaste 5000 years ago.
American sweet tooth: Americans spent $21 billion
on candy in 2001. That's more than the gross national products of
Lituania, Costa Rica and Mozambique combined!
Egyptians were among the first dentists. Some mummies
have teeth filled with a kind of resin and malachite. In other mummies,
gold wire has been used to bind loose teeth.
The greater the amount of time food remains in the
mouth, the greater the chance for decay.
The sequence that foods are eaten can determine the
risk for cavities. If you eat sugary foods after meals, you decrease
the chance for cavities, as opposed to eating sugary foods alone.
In the United States, close to 3 million miles of
dental floss was purchased in 1996 by dental consumers - enough
to circle the earth nearly 120 times!
During the middle ages, people went to barbers for
tooth extractions. These practitioners were called barber-surgeons
and were marked by the iconic red and white striped barber poles
that are still used today.
Anesthesia was invented by a dentist - Dr. Wells from
Hartford, CT. A monument dedicated to his contribution is located
in Bushnell Park in Hartford.
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Light micrograph of a transverse ground section
through the junction between enamel and dentin. A number of
tufts (so named because they resemble tufts of grass in ground
section) are visible extending from the junction into the enamel
above. Their presence and their development are an adaptation
to the spatial conditions in the enamel. |
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A polarized light image made through a ground
glass section of tooth enamel containing a carious lesion. This
microscopy technique utilizes birefringement measurements of
different solutions absorbed in the enamel to assess the porosity
of enamel mineral content as the solutions pass through the
cavity. Use of this technique has expanded our understanding
of the changes that take place in enamel during the development
of a cavity-now defined as a continuing process of demineralization/remineralization
involving the formation of four zones: surface zone, body of
the lesion, dark zone and translucent zone. |
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Longitudinal ground section through a permanent
tooth. The broad s-shaped course of the dentinal tubules (primary
curvature) show the path that the dentin forming cells (odontoblasts)
take when forming dentin matrix. A layer of cementum is visible
above. |
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A high power photomicrograph of a section of tooth
stained with a silver method to emphasize collagen fibers. The
alveolar bone is to the right and the dentin and cementum are
on the left. In between are the clearly defined periodontal
ligaments which insert into bone or cementum, called Sharpey's
fibers. |
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A photomicrograph of an anterior deciduous tooth
in the advanced bell stage of development, shown by this faciolingual
section. The stain used in preparing this slide(Mallory) colors
the enamel matrix red, and the dentin matrix blue. This stage
in tooth development occurs at approximately 18 weeks of age
for the mandibular primary incisors, the first teeth to erupt.
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A photomicrograph of the metaphysic of a growing
long bone, depicting endochondral bone formation. Epiphyseal
bone is above, and the trabecular bone of the metaphysic is
below. The chondrocytes near the top of the cartilaginous plate
proliferate, and become aligned in vertical columns. The cells
increase size at the bottom of the columns, and the cartilage
matrix between them mineralizes. This type of bone formation
is different from that of the bones of the face and skull, including
the mandible, which occur via intramembranous bone formation.
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High power light micrograph of cellular cementum
with two cementocytes visible. The space occupied by the cells
form canaliculi radiating out from the lacunae and directed
toward the periodontal ligament. Just as in the bone, nutrients
diffusing through the canaliculi maintain the viability of
these cells. The nutrients can not be obtained from the opposing
side which is blocked by a wall of dentin.
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A low power photomicrograph of a section near
the alveolar crest, displaying cemetum, gingiva and alveolar
bone. This picture illustrates the carying orientations of
periodontal ligament fibers depending on their location. Free
gingival fibers attach the gingiva to the cementum, while
alveolar crest fibers extend from the bone apex to the cemetum,
resisting occlusal or incisal displacement of the tooth.
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Low power micrograph of a section through a permanent
tooth. Incremental lines in the enamel (darker brown, outer
band), called striae of Retzius, and in the dentin (lighter
brown, inner band), called striae of von Ebner, provide a general
sense of how these layers are formed during crown development.
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