Milky white or light yellow

The higher the mineralization, the more transparent the enamel

Enamel crystals are similar to hydroxyapatite crystals

F- makes the calcium triangle structure within the apatite crystal compact and strengthens its stability, thus enhancing its resistance to acid.

Enamel extracellular matrix protein

An elongated columnar structure originating from the enamel-dentin junction, running through the entire enamel layer, and reaching the tooth surface.

The pits and fissures are radial

The cervical area of ​​the near teeth is almost horizontal

The near surface 1/3 is straight and the inner 2/3 is curved

Arrangement

Glaze pillar gap

Enamel sheath

Observe the longitudinal grinding section of the tooth using epilight, and you can see alternating light and dark bands of varying widths, distributed in the inner 4/5 of the enamel. Changing the angle of the incident light can change the light and dark bands.

reason

In the enamel that is first formed at the enamel-dentin boundary and in the approximately 30 μm thick enamel on the surface of most deciduous and permanent teeth, no enamel pillar structure can be seen, and the crystals are arranged parallel to each other.

reason

Observe the enamel grinding disc under low power. This line appears dark brown.

In the longitudinal grinding film, the tooth cusps are arranged in a ring around the tooth cusps, and the proximal tooth neck gradually forms a diagonal line.

In the transverse grinding disc, the growth lines are arranged in concentric rings.

Enamel growth lines are intermittent lines formed by periodic changes in the growth rate of enamel, and their width and spacing vary depending on the development status.

An aggravated growth line is commonly seen on the grinding discs of deciduous teeth and first permanent molars.

It is a thin plate-like structure perpendicular to the tooth surface, or stops in the enamel, or reaches the enamel-dentin junction, or extends into the dentin. The matrix there is incompletely calcified and contains a large amount of enamel protein.

Glaze panels contain a lot of organic matter, which can become a pathway for caries-causing bacteria to invade.

It originates from the enamel-dentin junction and spreads toward the tooth surface, taking on the shape of a tussock. The height is 1/5~1/4 of the enamel thickness.

It is a cluster-like image formed by the overlapping projection of some glaze pillars with poor mineralization and relatively high protein content in different planes and directions.

Spindle-shaped structure located at the enamel-dentin junction

More common at the apex of teeth

Its formation is related to the expansion of the terminal end of the odontoblast cytoplasmic process through the enamel-dentin junction and being embedded in the enamel.

The junction between enamel and dentin is not a straight line, but is formed by many small arcs connected

three dimensional angle

reason

Bacteria and food residues are easily retained in fissures and grooves and are difficult to clean, often becoming the starting point of caries.

Once caries occurs, it quickly spreads deep into the

Early sealing of fissures and grooves is helpful in preventing caries.

As age increases, the fissures and fissures gradually smooth out, and the incidence of caries in this area tends to decrease.

When treating caries and preparing a cavity, it is not appropriate to retain the suspended enamel that has lost dentin support.

The suspended enamel is easily broken when pressed under pressure after filling, causing cracks at the edges of the cavity and causing secondary caries.

A honeycomb-like rough surface is formed by partial dissolution of inorganic apatite in acid-etched enamel to enhance retention.

The degree of dissolution of the enamel surface is related to the arrangement direction of the enamel columns and crystals.