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A Biomimetic Root
Canal?
Progress has also been made with the inner
tooth structure - the dentin and pulp. Decay that destroys the tough
enamel covering of the tooth can also progress into the deeper dentin
layer and even into the pulp. The dental pulp is the innermost
structure of the tooth, consisting of connective tissue, nerves, and
blood vessels. The overlying dentin is produced by specialized cells,
called odontoblasts, which reside in the pulp. The dentin itself is a
mixture of matrix proteins and mineral, harder than bone, but not as
hard as enamel.
When pulp becomes infected, traditional treatments involove removal of
all infected or damaged tissues followed by filling the root canal and
replacing the dentin and enamel with synthetic materials.
Approximately 15 million patients in the U.S. require root canal
therapy each year. Two approaches are being pursued to regenerate the
tooth's internal structures. Direct application of TGF-beta family
proteins (BMP-2, -7, TGF-beta 1) onto exposed healthy pulp has
stimulated dentin formation in animal studies. A potentially more
versatile approach has been used in vitro to grow pulp-like tissue in
a three-dimensional scaffolding material. A combination of cultured
human pulp cells (fibroblasts) grown in a polyglycolic acid (PGA)
matrix produced new tissue histologically resembling pulp.
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