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51 Cards in this Set
- Front
- Back
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What are Short Term Incremental Lines?
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Cross striations in enamel due to the dinural cycle of amealoblasts. They are 4um in length.
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What are the Striae of Retzius?
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These represent disturbences in enamel production. Prominent Striae is the neo-natal line.
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What are Perikymata?
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Surface manifestaions of the Striae of Retzius.
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What are Hunter-Schreger bands?
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Bands caused by the change in direction of groups of enamel rods.
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What is gnarled enamel?
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When groups of enamel rods spiral around each other (eg under cusps)
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What is Primless enamel?
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Enamel when it is first or last laid down. Primless because there are no tomes processes. These areas are lighter because they have less organic matter.
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What feature strengthens the DEJ so there is stronger cohesion?
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Scalloping
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What are Enamel Tufts and where are they best seen?
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Tufts are hypocalcified enamel rods that go from the DEJ to the enamel. Best seen in transverse sections.
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What are Enamel Lamellae and where are they best seen?
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Lamellae are similar to geographical faults and are hypomineralised. Best seen in transverse sections.
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What are Enamel Spindles and where are they best seen?
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Spindles are remnants of odontoblast tubules. Mostly seen beneath cusps in longitudinal sections.
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What constitutes enamel?
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By weight:
Hydroxyapatite - 96% Water - 2% Organic - 2% |
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What constitues dentine?
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By weight:
Inorganic - 70% (smaller hydroxyapatite than enamel) Water - 10% Organic - 20% (mostly type I collagen, also glycosaminoglycans) |
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What is Predentine?
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Unmineralised dentine (newly laid)
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In what shape is predentine mineralised and how long does it take?
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It can either have a linear mineralisation front (when it occurs slowly) or occur in a globular form. It takes around 1 day.
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Which is more mineralised? Peritubular or Intertubular Dentine?
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Peritubular
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What kind of dentine suround odontoblast tubules? What is it's composition?
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Peritubular dentine - highly mineralised.
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What kind of dentine is between dentine tubules? What is it's composition?
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Intertubular dentine - high levels of collagen fibres enveloped in amorphous protein.
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What is newly formed dentine called?
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Mantle dentine
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What is the name of dentine laid down before root formation is complete?
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Primary dentine
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What is the name of dentine laid down after root formation is complete?
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Secondary dentine - decreases of pulp chamber with age
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What happens to dentine tubules as they run from Primary to Secondary dentine? Why?
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They bend sharply due to odontoblast crowding.
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Tertiary dentine?
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Reparative
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What is Sclerotic dentine?
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Mineralised dentine tubules which are transparent.
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What is interglobular dentine?
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Hypomineralised dentine caused by globular dentine not fusing completley.
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What are the lines of Von Ebner?
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Short term incremental lines in dentine
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What are Contour line of Owen?
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Lines showing disturbance in dentine production.
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Where and what is the Granular Layer of Tomes?
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The Granular Layer of Tomes is located in dentine under cementum and may possibly be due to dentine tubules crossing back/looping.
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What cells are contained in dental pulp?
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Odontoblasts, reserve cells, fibroblasts, macrophages & odontoclasts
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What vessels are contained in the dental pulp?
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Aerterioles, capillaries, venules, Arterio-venous anastomes.
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What are vessels of the dental pulp inervated by?
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Vasomotor fibres of the autonomic ganglia
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Which nerve fibres of the dental pulp are myelinated? Vasomotor or pain fibres?
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Pain fibres
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When is the myelinated sheath lost?
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Subodontoblastic zone - Cell Free Zone of Weil
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Where is the Cell Free Zone of Weil?
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Under the odontoblasts
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What is the name of the nerve plexus in the subodontoblastic zone?
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Plexus of Raschkow or Parietal Plexus
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What are the 3 types of nerves that innervate dentine?
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Recurrent - go from POR to predentine and back
Predentine - go from POR to predentine Intratubular - go from POR to dentinal tubules |
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What cells of the developing tooth bud become cementoblasts?
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Cells of the Dental Follicle.
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Which cells of the developing tooth bud become amealoblasts?
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Inner Enamel Epithelial cells of the Enamel Organ
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Which cells of the developing tooth bud become Odontoblasts?
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Cells of the Dental Papilla.
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Where is acellular cementum located? What does it supply attachments for?
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In the cervical region. It supplies attachments for the PDL
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Where is cellular cementum found? What does it contain?
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Cellular cementum is found apically. It contains cementocytes in lacunae.
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Cementocyte lacunae canniculi are directed towards what?
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The PDL which has a blood supply
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What are Sharpey's/Extrinsic/Principle fibres made by? What are they made from and are they mineralised?
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Fibroblasts. Made from collagen, and they are mineralised.
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Name the 5 groups of Sharpey's/Extrinsic/Principle fibres, from cervix to apex.
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Alveolar Crest
Horizontal Oblique Appical Interradicular |
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Name the 5 main groups of the Gingival Ligament.
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Dentogingival
Alveologingival Circular Dentoperiosteal Interdental |
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What is bundle bone/lamina dura/cribriform plate? What are some features?
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Alveolar bone + Sharpey's fibres. Lots of forima and no trabeculae.
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What is the name of the areas between Sharpey's Fibres?
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Interstitial space
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What are the elastic fibres in the PDL called and what is their development state?
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Oxytalan fibres - immature
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By what mechanism does the cartilage of the condyles develope?
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Intramembranous Ossification
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Does the condyle cartilage of the TMJ have a perichondrium?
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Yes
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How many minisci are in the TMJ?
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One - complete
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What are the 3 theories of Dentine sensitivity?
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1. Dentine is innervated directly
2. Odontoblasts act as receptors and have gap junctions between each other and nerve fibres for communication 3. Hydrodynmaic theory: Receptors in pulp are stimulated via fluid movement through the tubules- this explains why local anaesthetics don't work |
