Module 11 Lab

Question 1

The specific gravity of the enamel:

Answer 1

2.8

Question 2

The 96% inorganic substances of enamel:

Answer 2

Calcium Hydroxyapitite crystals

Question 3

The 4% organic substances of enamel:

Answer 3

Water and proteins, including amelogenins, and enamelins

Question 4

Basic unit of enamel, appears in a keyhole of fish scale pattern in cross section.
Extends the width of the enamel thickness from the DEJ to the outer surface

Answer 4

Enamel rods and Prisms

Question 5

_____ ameloblasts are needed to produce one enamel rod.

Answer 5

Four

Question 6

Alternating light and dark bands, this is due to the periodic changes in the direction of enamel rods and can only be seen through a special light.

Answer 6

Hunter – Schreger Band (HSB)

Question 7

Highly convoluted arrangements of rods at the cusp tips and incisal edges, represents irregular intertwining of bundles of rods from the DEJ

Answer 7

Gnarled Enamel

Question 8

An incremental Lines of Retzius; Raised lines representing the outer manifestation of the Striae of Retzius.

Answer 8

Imbrication Lines of Pickerill

Question 9

An Incremental Lines of Retzius; Enhanced Striae of Retzius differentiating the prenatally deposited enamel to postnatal one. Results from abrupt change in the environment and nutrition of the infant.

Answer 9

Neonatal Line or Ring

Question 10

An incremental Line of Retzius; Tranverse wave-like grooves representing the outer manifestations of the Striae of Retzius.

Answer 10

Perikymata

Question 11

Secretory parts of ameloblasts; also the projections of ameloblasts into the enamel matrix.

Answer 11

Tome’s Processes

Question 12

Last secretory product of the ameloblasts; usually worn away by mastication and cleaning.

Answer 12

Primary Enamel Cuticle / Nasmyth’s Membrane

Question 13

Lines crossing the rods at 4 microns interval marking the daily apposition always growth of enamel rods.

Answer 13

Transverse Striations

Question 14

Extends from the enamel into the dentin. Consists if a linear, longitudinally oriented defects filled with organic material.

Answer 14

Enamel Lamella

Question 15

Hypoclacified areas projecting from DEJ into the enamel. Appears branched and contains greater concentration of enamel protein. Developmentally occurs because of abrupt changes in the direction of groups of rods that arise from different regions of the DEJ.

Answer 15

Enamel Tufts

Question 16

These are odontoblastic processes that sometimes cross the DEJ, it is the cause of DEJ hypersensitivity during cavity preparation

Answer 16

Enamel Spindles