Flashcards in Chapter 20 Deck (76)
where does the ameloblasts lay down a matrix of mucopolysaccharide and organic fiber next to the dentin matrix?
Where is the CEJ formed?
What has genetic control over the tooth shape?
What is the hardest structure of the body?
Enamel is generally what color?
Enamel can appear what color at times and why?
yellowish because of the reflection of the underlying dentin
Composition of enamel is
96% inorganic (Hydroxyapatite)
Other 4% of enamel is composed of what
Water and fibrous organic material
Enamel rod is made up of what?
What is the primary unit of enamels structure?
a column of enamel that runs from the Dentinoenamel Junction to the surface of the tooth
Enamel rod is Perpendicular to
The DEJ and the surface of the crown
Lays down matrix to form enamel
where does Ameloblasts begin to lay down Matrix
At the tip of the cusp and then further toward the cervical line
Ameloblast lying down matrix is referred to as
the mineralization stage of enamel rod calcification
The second stage of calcification is called the
what happens in Maturation stage
Crystals should grow in size until they are tightly packed together
When is there a change in development of the enamel rod
every 4 days
when change in development of enamel rod occurs and a brownish line develops in the enamel it is called
Striae of retzius
On the labial surface of the crown you can se horizontal lines on the crown due to
Striae of Retzius
Horizontal lines that can be seen on crown of Anterior teeth are called
Imbrication lines are
surface manifestations of the striae of retzius
The final job of ameloblasts is to
lay down a protective layer over the enamel
Protective layer of the enamel created by ameloblasts is called
Primary enamel cuticle
Another name for Primary enamel cuticle is
Nasmyths membrane (Primary Enamel Cuticle) covers
the crown and remains there for many months after eruption until worn away by toothbrushing and other abrasion
when spots or entire areas of the teeth appear white to whitish yellow in color
hypocalcified enamel the result of
insufficient growth of the enamel crystals or an insufficient number of crystals originally deposited in the matrix
hypocalcification can be termed