Enamel And Its Significance In The Study Of Cariology Flashcards
An acellular, avascular, and highly mineralized material that covers the anatomic crown of a tooth.
Enamel
Thickness of the enamel at the incisal edges of incisors
2mm
The enamel gets progressively thinner towards the CEJ.
False
A hard, stiff, and wear resistant tissue.
Enamel
The 96% inorganic material in the enamel.
Hydroxyapatite
Development of the dental lamina from the oral epithelium.
Initiation stage
Proliferation of the dental lamina into ectomesenchyme.
Bud stage
Proliferation and differentiation to form the tooth germ.
Cap stage
The innermost margin of the cap shape of the enamel organ forms the future crown form of the tooth, such as cusps.
Enamel knots
Differentiation of the enamel organ and dental papilla into different layers.
Bell stage
Differentiation of preameloblast to ameloblasts and beginning of amelogenesis from Tomes process.
Apposition stage
Not a true process, and is the projection of the secretiry end of each ameloblast that faces the DEJ
Tomes process
Fuses with the oral epithelium then degenerates.
Reduced Enamel Epithelium (REE)
Green-gray residue of the fused tissue of the REE and oral epithelium.
Nasmyth membrane/Primary enamel cuticle
The 4 lobes of the anterior teeth.
Medial, labial, distal, lingual
Deep invaination of the enamel surface, resulting from failure of the developmental lobes to coalesce.
Fissures
Non-coalesced enamel at the deepest point of a fossa
Pits
Fundamental crystalline organizational unit of enamel
Enamel rods
The enamel rods are prismatic in cross-section but become irregular once fully matured
True
Structural components of enamel rods that are millions of small and vary in size and shape
Apatite crystallites
Organically rich interspace
Rod sheath
Pit and Fissure caries appears smaller than assumed at the surface
False
Occurs near the cervical regions and incisal and occlusal areas, and is not subject to fracture as much as regular enamel.
Gnarled enamel
Alternate light and dark zones of varying widths that have slightly different permeability and organic content.
Hunter-Schreger Bands
Hypomineralized enamel structures of the enamel rods and interrod substance that project between adjacent groups of rods from teh DEJ
Enamel tufts
Odontoblasts that crossed the basement membrane before it mineralized into the DEJ
Enamel spindles
Thin, leaf-like faults between enamel rod groups that extend from the enamel surface to the DEJ, sometimes into dentin.
Enamel lamellae
The enamel lamellae contain mostly inorganic material.
False
Series of alternating grooves formed when striae of Retzius circles are incomplete at the enamel surface
Imbrication lines of Pickerill
Elevations between the grooves, usually continuous around a tooth and usually lie parallel to the CEJ and each other.
Perikymata
The interface of enamel and dentin.
Dentinoenamel Junction
Outline of the DEJ
scalloped or wavy
The enamel hardness and density decreases towards the DEJ.
True
Teeth have very thin enamel that chips off or have no enamel at all, and there are yellow crowns due to exposed dentin.
Amelogenesis imperfecta
Type of Amelogenesis Imperfecta with defective matrix formation and the enamel is not formed to full normal thickness.
Type I: Hypoplastic Amelogenesis Imperfecta
Reduction in quantity of enamel matrix; pitting and grooves on the enamel surface.
Enamel hypoplasia
Type of Amelogenesis Imperfecta wherein the enamel crystallites remain immature, normal thickness. The defective enamel can be chipped away from the dentin matrix using an instrument under firm pressure.
Type II: Hypomature Amelogenesis Imperfecta
Reduction in the quality of the enamel maturation; opaque, yellower, or even browner due to intrinsic staining.
Enamel hypocalcification
Caused by excessive systemic fluoride during enamel matrix formation and calcification
Fluorosis
Pit and fissure take up the configuration following the direction of enamel rods wherein the broader base is oriented towards the enamel surface
True
Gnarled enamel appears as concentric circles in enamel due to the incremental formation of the enamel
False
