Dentine Flashcards
Where is Peritubular dentine?
Walls of tubules Highly mineralised Also known as intratubular dentine
Where is Intertubular dentine?
Between the tubules Highly mineralised Forms the bulk of dentine around the dentinal tubulesWhat
Where is Mantle dentine?
Outermost layer along the DEJ First dentine formed in a band of 150um wide Is mineralised by matrix vesicleswhat is granular layer of Tomes
What is Primary dentine?
Forms prior to eruption Rapidly formed more mineralised than secondary Contains incremental lines
What is secondary dentine?
Formed after completion of root formation Formed slower & less mineralised than primary Increases the thickness of dentine Causes the canals to get smaller over time
What is Tertiary dentine?
Formed as a result of injury/trauma Traumatic cavity prep Irregular pattern of tubules
What is granular layer of Tomes?
Thin layer of dentin adjacent to the cementum Only root surface Just beneath the Hyaline layer Branching and looping of tubules
What is Contour lines of Owen?
Accentuated incremental lines in the dentin thought to be due to disturbances in the mineralization process. Only found in the crown area
What is globular dentine?
Layer between the mantle & circumpupal Only in Crown coronal portion This form of dentin is hypomineralized
What are the 3 types on dentine
Primary Secondary Tertiary
What does peritubular dentine consist of?
Lacks collagen fibrous matrix 15% more mineralised than intertubular Crystals-carbonated apatite
What is in the root layer of dentine?
Hyaline layer - Glass like or clear lies just outside the granular layer Grandular layer of Tomes - in the root not crown Circumpupal dentine
What is in the crown layer of dentine?
Mantle dentine - The outer most layer of dentine Interglobular dentine - where minerals are deposited Circumpupal dentine - Bluk of dentine
What is the Hyaline layer?
Most peripheral layer initially unmineralised dentine 0.5-0.8 μm thick Contains enamel matrix-like protein Initial fibers of the periodontal ligament embed Aids cementum in binding to the dentine Very narrow, non-tubular structure-less band
What chemicals are in Interglobular dentine?
Sulfur - see in crown
What chemicals are in Tomes granular layer?
Calcium & Phosphorus - see in root
What is Predentine?
The innermost layer of dentine 10 to 40 μmin thickness Thicker in young teeth Non-mineralised Always adjacent to pulp tissue Very Pale in colour
What is Predentine composed of?
Collagen & proteoglycans secreted produce Metadentin Matrix deposition precedes mineralisation Secreted by odontoblasts ◦Golgi apparatus◦Mitochondria
What is Translucent dentine?
Forms with aging due to tubule occlusion by peritubular dentine Found at the root apex Used in forensic dentistry to tell age
What is Sclerotic dentine?
Tubular occlusion by a stimulus Similar appearance to translucent dentine but related in site to the stimulus
What does Sclerotic dentine do?
They can just shut down, this is believed to be a protective mechanism to pulp & increase with age
What are Dead tracts?
When dentine is damaged, odontoblastic processes die or retract leaving empty dentinal tubules, termed dead tracts DT When the dentinal tubules are opened or sufficiently irritated, their contents coagulate and die.
How do we get Dead tracks?
What dentine is damaged odontbalstic process dies leaving empty tubules DT Odontoblastic processes killed by a stimulus Empty tubules
What do Dead tracks look like?
Appear dark under transmitted light microscope
What are the layers of dentine?
Looking at the layers of detnine.
