Role in Tooth Decay
Early colonizers of the tooth surface are mainly Neisseria spp. and streptococci, including S. mutans. The growth and metabolism of these pioneer species changes local environmental conditions (e.g., Eh, pH, coaggregation, and substrate availability), thereby enabling more fastidious organisms to further colonize after them, forming dental plaque. Along with S. sobrinus, S. mutans plays a major role in tooth decay, metabolizing sucrose to lactic acid using the enzyme Glucansucrase. The acidic environment created in the mouth by this process is what causes the highly mineralized tooth enamel to be vulnerable to decay. S. mutans is one of a few specialized organisms equipped with receptors that improve adhesion to the surface of teeth. Sucrose is used by S. mutans to produce a sticky, extracellular, dextran-based polysaccharide that allows them to cohere, forming plaque. S. mutans produces dextran via the enzyme dextransucrase (a hexosyltransferase) using sucrose as a substrate in the following reaction:
- n sucrose → (glucose)n + n fructose
Sucrose is the only sugar that S. mutans can use to form this sticky polysaccharide.
However, many other sugars—glucose, fructose, lactose—can be digested by S. mutans, but they produce lactic acid as an end-product. It is the combination of plaque and acid that leads to dental decay. Due to the role the S. mutans plays in tooth decay, there have been many attempts to make a vaccine for the organism. So far, such vaccines have not been successful in humans. Recently, proteins involved in the colonization of teeth by S. mutans have been shown to produce antibodies that inhibit the cariogenic process. A molecule recently synthesized in Yale University and University of Chile called Keep 32 is supposed to be able to kill Streptococcus mutans.
Read more about this topic: Streptococcus Mutans
Famous quotes containing the words role in, role, tooth and/or decay:
“Friends serve central functions for children that parents do not, and they play a critical role in shaping children’s social skills and their sense of identity. . . . The difference between a child with close friendships and a child who wants to make friends but is unable to can be the difference between a child who is happy and a child who is distressed in one large area of life.”
—Zick Rubin (20th century)
“Certainly parents play a crucial role in the lives of individuals who are intellectually gifted or creatively talented. But this role is not one of active instruction, of teaching children skills,... rather, it is support and encouragement parents give children and the intellectual climate that they create in the home which seem to be the critical factors.”
—David Elkind (20th century)
“If she must teem,
Create her child of spleen, that it may live
And be a thwart disnatured torment to her!
Let it stamp wrinkles in her brow of youth,
With cadent tears fret channels in her cheeks,
Turn all her mother’s pains and benefits
To laughter and contempt, that she may feel
How sharper than a serpent’s tooth it is
To have a thankless child!”
—William Shakespeare (1564–1616)
“It had been a moving, tranquil apotheosis, immersed in the transfiguring sunset glow of decline and decay and extinction. An old family, already grown too weary and too noble for life and action, had reached the end of its history, and its last utterances were sounds of music: a few violin notes, full of the sad insight which is ripeness for death.”
—Thomas Mann (1875–1955)