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150 Cards in this Set
- Front
- Back
Types of epithelial tissue |
1. Simple (Squamous, cuboidal, columnar, pseudostraified) 2. Stratified (Squamous, columnar, transitional) |
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Neural tissue |
arise from neuroepithelial cells (Neurons & neuroglia) |
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Neurons |
Nerve cells that receive and conduct impulses & regulate muscle and gland activity |
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Neuroglial cells |
Supporting cells of nervous system, some phagocytic |
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Parts of a neuron |
Cell body (perikaryon)= contains nucleus& cytoplasm Axons= Conduct nerve impulses from the nerve cell body, terminates into axon terminals (Schwann cells, nodes of Ranvier, myeline sheath) Dendrites= receive and conduct impulses to the cell body |
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Connective tissue |
Bone, Adipose (fat) and Blood tissue |
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Connective tissue proper |
1. Loose connective tissue 2. Dense connective tissue (regular/irregular) 3. Loose connective tisse w/ special prop. (mucous, elastic, reticular, adipose,pigment) |
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Muscle tissue |
1. Skeletal (voluntary) 2. Smooth (involuntary) 3. Cardiac |
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List types of connective tissue proper |
mucous, elastic, reticular,adipose, pigment |
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Explain the function of cartilage |
specialized connective tissue, halfway point between other tissues |
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Describe the functions of involuntary muscle |
assists with digestion and movement of food through the alimentary canal cardiac muscle pumps through blood vessels |
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List the non stratified epithelial cell types |
Simple: squamous, cuboidal, columnar, pseudostratified |
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List the types of cartilage |
hyaline, elastic, fibrous |
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Explain how the sympathetic and parasympathetic nervous systems work together |
sympathetic- increases activity parasympathetic- decrease activity |
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what are the types of tissue in the human body |
epithelial, muscle, connective, neural |
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List the two cells that teeth develop from |
oral ectoderm cells and mesenchymal cells |
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oral ectoderm cells |
Form enamel organ... enamel organ forms enamel |
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mesenchymal cells |
form the dental papilla then differentiates to form dentin located under IEE dental sac/follicle surrounds enamel organ & dental papilla |
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list the stages of tooth development according to the shape of the epithelial enamel organ |
1. Initiation 2. Bud stage 3. Cap stage 4. Bell stage 5. Apposition 6. Crown formation 7. Root formation 8. Eruption |
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define the initiation of odontogenesis |
6-7 weeks, 1st sign of tooth formation epithelial & mesenchymal cells interact dental lamina pushes into mesenchyme to develop 2 tooth buds for primary teeth |
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define successional lamina |
for each primary tooth formed behind and lingual to it forms a permanent tooth that will precede it forms all permanent teeth except molars |
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During tooth formation where do permanent molars form from |
a distal extension of the general dental lamina nonsuccedaneous |
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how do neural crest cells contribute to the development of teeth |
salivary glands, bone, cartilage, nerves, face muscles |
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define the bud stage of odontogenesis |
8th week, round growth of ectodermal cells surrounded by mesenchymal cells |
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define the cap stage of odontogenesis |
9-10th weeks proliferation, differentiation, morphogenesis unequal growth forms concave surface Epithelium/ ectoderm forms enamel organ which forms a-blasts to form enamel of tooth |
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What does the enamel organ consist of? What does it eventually form? |
Inner enamel epithelium Stratum intermedium Stellate reticulum Outer enamel epithelium =forms enamel |
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What do the cells of the outer enamel epithelium do (OEE) |
covers the enamel organ organize a network of capillaries that bring nutrition to a-blasts |
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What do the cells of the inner enamel epithelium do (IEE) |
become the ameloblasts form the blueprint for the shape of the crown |
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describe the stellate reticulum cells |
between the IEE & OEE star shaped with processes attached to each other |
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describe the stratum intermedium cells |
lies adjacent to IEE assists the a-blasts with formation of enamel |
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describe dental papilla |
densely packed cells (mostly fibroblasts) w/ blood vessels in central and peripheral regions differentiates into odontoblasts which form dentin |
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what are the components of the dental sac? what is another name for the it? |
dental follicle Periodontal ligament, alveolar bone, cementum |
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define the bell stage of odontogenesis |
11-12th weeks morphodifferentiation, histodifferentiation -mesenchyme cells elongate to form collagen fibers (predentin/ dentin matrix) -increment calcifies within 24 hours -once several layers are formed a-blasts form enamel matrix |
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During odontogenesis what differentiates first ameloblasts or odontoblasts? |
Ameloblasts differentiate first causing odontoblasts to locate adjacent to them |
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during odontogenesis, odontoblasts differentiate establishing... (describe process) |
-a basement membrane between odontoblasts and ameloblasts -begin dentinogenesis -they then form dental matrix (predentin) |
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dentin is formed in two phases (dentinogenesis) |
1. collagen matrix formation 2. deposition of calcium phosphate (hydroxyappatite) crystals in matrix |
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Describe the process that pre-ameloblasts of through |
1. nuclei polar away from the basement membrane 2. then differentiate into a-blasts & induce cells of dental papilla to differentiate to odontoblasts |
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what keeps ameloblasts in a row as they move outward depositing enamel matrix |
desmosomes |
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define Tomes' process |
short, conical process at the apical end of an ameloblast during secretory stage |
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where do the terminal bar apparatus (junctional complex) appear |
near cell body & tomes' process |
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list the stages of growth and maturation of the ameloblasts |
1. morphogenesis 2. differentation/ orientation 3. secretion 4. maturation 5. protection maybe dan should make pancakes |
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define the apposition stage of odontogenesis |
induction, proliferation varies by tooth |
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define the crown formation stage of odontogenesis |
completed before root formation |
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define the root formation stage of odontogenesis |
varies by tooth |
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define the eruption stage of odontogenesis |
varies by tooth |
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describe the process of dentinogenesis |
odontoblasts elongate & an odontoblastic process forms at the proximal end adj. to the DEJ odontoblasts move to the center of the pulp, odontoblastic process elongates & stays inside dental matrix (predentin) once calcified - dentinal tubules |
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describe the process of amelogenesis |
begins after a few microns of dentin are deposited during bell stage cells of IEE elongate and go thru 5 stages (morphogenesis, organization, secretion, maturation, protection) amelogenin= protein produced in enamel matrix cusp tips form initially |
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describe the process of crown maturation |
as amelogenesis is completed & amelogenin is deposited matrix starts to mineralize 25% mineral deposition, 70% due to crystals growing -protein of enamel matures to enameling -terminal bar apparatus disappears & enamel surface is smooth -increase in mineral content -a blasts secrete organic cuticle |
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reduced enamel epithelium |
shortened a-blasts contact the enamel organ components and fuse them together this cellular covering remains on the enamel surface until tooth erupts |
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cervical loop |
most cervical portion of enamel organ =IEE & OEE forms root after crown shaped forms epithelial root sheath of hertwig to shape the roots |
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her twigs epithelial root sheath |
disintegrates when predentin is produced remnants termed epithelial rests of Malassez |
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Epithelial diaphragm |
encircles apical opening of root and allows it to grow in length tapers down to 1-3mm |
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when do primary and permanent teeth begin developing |
primary teeth- begin development in utero and crown completes mineralization before birth permanent teeth- begin formation at or after birth |
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the dental sac forms |
periodontal ligament alveolar bone cementum |
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tooth germ consists of |
the dental sac the enamel organ the dental papilla |
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list the phases of enamel production |
collagen matrix formation & hydroxyappetite crystals deposit into the matrix, crystals spread until matrix is calcified predentin formed in increments along the pulpal border, predentin formed from the previous day becomes dentin |
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what are the 1st and last areas to calcify in the crown |
1st mineralized in the DEJ, final is the cervical region of the crown |
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____ are the forming cells |
odontoblasts |
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another term for the dental sac is ____? |
dental follicle |
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where predentin and enamel matrix meet and then calcify will become the future |
dentinoenamel juction (DEJ) |
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the ____ is where cells of the inner and outer enamel epithelium meet |
cervical loop |
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true or false the dental lamina begins to develop in the dental arches starting at the midline |
true |
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when ameloblasts mature they elongate, their nuclei will polarize away from the basement membrane. What is the name of the short, conical, secreting end of the ameloblast (the party hat)? |
Tomes' process |
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list the phases of eruption |
1. pre eruptive phase 2. pre functional eruptive phase 3. functional eruptive phase |
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describe the preeruptive phase |
begins at time of early initiation& formation ends at initiation of roots developing crowns move constantly in the jaws developing crowns move constantly in jaws under gingiva, all movement occurs within the crypts of the developing crown before root formation begins |
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how do maxillary molars develop in the tuberosities during the pre eruptive phase |
develop in the tuberosities, they slant distally |
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how do mandibular molars develop in the tuberosities during the pre eruptive phase |
develop in the rams and slant mesially |
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describe the prefunctional phase |
begins at initiation of root formation until teeth reach occlusal contact tooth in oral cavity but does not occlude 4 events occur (root formation, mvmnt, penetration, occlusal/incisal mvmnt) changes in tissue(above, below, around) |
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what are the four events that occur during the pre-functional phase |
1. Root formation: roots elongate, proliferation of epithelial root sheath 2. Movement: crowns move incisally/ occlusally into oral mucosa, REE fuses w/ epithelial layers 3. Penetration: crown tip erupts through fused epithelial layers, primary cuticle covers enamel 4. Intraoral occlusal/incisal mvmnt: crown continues to move through mucosa until clinical contact with the opposing crown , apical shift of gingival attachment |
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describe the changes in tissue overlying the teeth during the pre functional phase |
-dental follicle forms an eruption pathway
-gubernaculum dentis/ gubernacular cord guides tooth movements -macrophages & osteoclasts clear tissue & bone for tooth eruption -osteoclasts/ osteoblasts remodel bone (form ruffled border) -roots of primary teeth are resorbed -blanching in mucosa |
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what is the eruption pathway |
inverted triangular area overlying the teeth |
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during the pre-functional phase of tooth eruption what do macrophages do? |
release hydrolytic enzymes that destruct cells and fibers clear tissue and bone for tooth eruption (along with osteoclasts) |
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hard tissue is resorbed in two phases during the pre functional eruptive phase: |
1. extracellular 2. intracellular |
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describe the changes in tissue surrounding the teeth during the pre functional phase |
tissue changes from delicate fine fibers to bundles of fibers fibroblasts form& degrade collagen fibers alveolar bone crypt elongates blood vessels develop |
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describe the changes in tissue underlying the teeth during the pre functional phase |
bone compensates for root growth collagen fibers form and attach to cementum |
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functional eruptive phase |
final phase, occurs after teeth are in occlusion until they aren't present anymore alveolar bone height increases, mineral density increases root completion PDL increases in dimesion, orientation & they're blood vessels become organized wear occurs& deposit more cementum |
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how long does the root completion process take for primary/ permanent teeth |
primary 1- 1 1/2 years permanent 2-3 years |
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list the reasons for tooth eruption |
1. root growth and pulpal pressure 2. cell proliferation, PDL formation 3. endocrine, vascular & enzymatic degredation 4. increased pressure to decreased pressure |
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define shedding |
loss of primary dentition caused by resorption of the roots, loss of bony support and inability to withstand masticatory forces |
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What are the approximate ages of tooth development for primary and mixed dentition |
primary dentition: 2-8 years old mixed dentition: 8-12 years old |
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list the causes of tooth shedding |
1. crown can't withstand masticatory forces 2. bone loss 3. root resorption 4. toot eruption |
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define tooth eruption |
process by which teeth emerge into the oral cavity, a stage coordinated with root growth and maturation of tissues surrounding the tooth, including the alveolar bone |
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the ____ found overlying the erupting teeth are believed to guide the teeth in their movement to ensure complete eruption |
gubernaculum dentis/ gubernacular cord |
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define diphyodont |
species that has two sets of teeth within their lifetime (primary/ permanent) |
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explain the origin of osteoclasts |
form from monocytes in the bloodstream |
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compare/ contrast primary & permanent dentition |
primary: 20 total teeth, crowns smaller, roots shorter, prism less surface, enamel thinner, dentin softer, pulp larger permanent: 32 total teeth, crowns larger, roots larger, not prism less, enamel 2x thicker, dentin harder, pulp smaller |
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describe enamel |
hardest tissue in th ebody, withstands mastication, brittle, provides shape and contour of crown |
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what is the structural unit of enamel, describe it |
interlocking rods/prisms Surface= sheath (organic) Center= core crystalline structure, extends from DEJ to outer surface of tooth perpendicular to DEJ (90-60° angle) |
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what is the physical properties of enamel |
96% inorganic mineral (hydroxyappetite) 4% water & organic matter (protein enamelin) |
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what does the protein enamelin derive from? describe enamelin |
amelogenin similar to keratin up to 2.5mm occl/inc |
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how many ameloblasts form a rod? what are the parts of a prism? |
4 a-blasts form 1 rod/prism head= 1 a blast neck= 2 a blast neck= 1 a blast in cross section looks like keyhole approx size of RBC |
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True/ False enamel rods are shortest in the cusps/ incisal edges |
False enamel rods vary in length, longest in the cusps/ incisal edges, shorter at CEJ |
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what is the inorganic material that makes up enamel? what is the chemical equation? |
hydroxyapetite Ca10(PO4)6(OH)2 |
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hunter schreger bands |
alternating light and dark bands due to orientation of crystals within the enamel rods |
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Lines of retzius |
incremental lines, stain brown, cross striations of enamel rods (rings of a tree) Striae of Retzius |
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incremental lines |
result of rhythmic recurrent deposition of enamel |
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neonatal line |
line of retzius formed by parts of the enamel before and after birth line, formed due to environment/ nutrition change during birth |
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enamel lamellae |
seen with naked eye, extends from surface of DEJ, organic spaces between groups of rods longer/ narrower than tufts appear leaf like |
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reasons why enamel lamellae may form |
1. during development creating organic pathway 2. spaces between groups of rods occurring because of impact and temp change |
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enamel tufts |
defects on the inner 1/5- 1/10 of enamel dark brushlike structures between groups of enamel rods filled with enamelin |
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enamel spindles |
"misnomer" dentinal tubules past DEJ shorted than tufts |
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perikymata/ imbrication lines |
ridges and grooves on non-masticatory surfaces caused by hesitation of a-blasts associated with lines of retzius |
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prismless enamel |
20-40 um thick zone, no hunter schreger effect appears as a structureless area |
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microlamellae |
minute spaces between and around enamel rods contributes to microporosity |
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during etching ___ resist etching because of ____ and the ____ becomes etched because it is more sensitive. |
the rod sheath the organic material (hydroxyapetite) core |
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describe the effect of fluoride and the mineral component of enamel |
enamel can be remineralized by low levels of fluoride, it can never be replaced but it can be made stronger |
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what is gnarled enamel? where is it located? |
enamel rods intertwine at the cusp tip outer enamel rods run nearly perpendicular to the surface of the enamel inner groups of rods alternate and they meet and twist |
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dentin |
living tissue, bulk of tooth, surrounds pulp, not clinically seen, softer than enamel more radiolucent, slightly elastic, less brittle more yellow than enamel |
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physical properties of dentin |
70% inorganic hydroxyapatite crystals 20% organic collagen fibers 10% water by weight |
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what is the structural unit of dentin, describe it |
dentinal tubule- avascular spaces, extend from DEJ/ DCJ to wall of pulp primary& secondary curvature (s shape) pass thru interlobular dentin crowded near pulp |
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what are the three classifications of dentin |
primary, secondary and tertiary |
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predentin |
newly formed unmineralized, not calcified dentin forms in two stages 4um of predentin is deposited and calcified each day |
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contents of dentinal tubules |
odontoblastic process dentinal fluid space possible nerve axons |
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odontoblastic process |
attaches to cell body may not extend entire length of tubule |
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dentin is formed in two stages |
1. the organic matrix is deposited 2. an inorganic substance is added |
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primary dentin |
1st dentin formed, at CEJ composed of mantle & circumpulpal dentin forms bulk of tooth forms prior to tooth eruption tubules from pulp to DEJ |
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mantle dentin |
150um thick, 1st primary dentin formed covering over the rest of dentin deposited on DEJ moves pulpward mineralized by matrix vesicles large collagen fibers, less mineralized, fewer defects than collagen fibers |
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circumpulpal dentin |
6-8mm thick in crown, thinner in roots underlies mantle& globular dentin fibers are 10x smaller than those in mantle dentin |
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secondary dentin |
normal circumpulpal dentin after tooth eruption 1- 1.5 um incremental lines forms after root completion, crown in occl forms slower deals w/ forces of mastication |
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globular (interglobular) |
zone of disturbed dentin that separates mantle dentin from the circumpulpal dentin arc shapes between globules interglobular- spaces between globules |
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tertiary dentin |
formed quickly in response to injury tubules irregular "reparative, osteodentin" |
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peritubular dentin |
"intratubular dentin: forms walls of tubules highly mineralized missing from tubules of interlobular dentin not present in interlobular dentin (box of straws, straws= highly mineralized spaces= less mineralized) |
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intertubular dentin |
fills in space between tubules highly mineralized but less than intratubular dentin |
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list the types of primary dentin |
mantle, globular, circumpulpal, intratubular, intertubular |
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list the types of tertiary dentin |
reactionary/ response dentin reparative dentin osteodentin sclerotic dentin |
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imbrication lines of von ebner |
dark stained bands 4um in width perpendicular to tubules every 5th line shows collagen change |
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granular layer of Tomes' |
thin calcified section of root underlying the cementum root dentin near DCJ disoriented odontoblasts cause tubules to form right angles before heading for pulp |
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dead tracks |
loss of tubular contents indicates air in tubules increased permeability black lines |
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smear layer |
helps block tubules during a preperation |
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what type of varnish/ liner can you use to seal dentinal tubules |
calcium hydroxide |
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sclerotic dentin |
tubules are obliterated protects pulp from bacteria "transparent dentin" |
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factors that increase permeability |
1. tubules are cone shaped & permit increased permeability from the cavity wall or floor of the pulp 2. system of branching tubules increases the permeability 3. loss of odontoblastic process (dead tract) increases permeability |
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the type of dentin that compromises the greater part of the crown |
primary dentin |
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area of newly formed collagenous fibers that borders the pulp |
predentin |
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location and composition of the granular layer of dentin |
root dentin near CEJ, thin calcified section of root underlying the cementum that covers the root proceeding from the CEJ to the root apex |
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Humans have ___ amount of pulps |
52 (20 in primary, 32 in permanent) |
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pulp |
soft, gelatinous .2mL volume surrounded by dentin molar teeth pulps are 4x's larger than incisors |
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what are the two forms of pulpal tissue |
coronal pulp radicular pulp |
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coronal pulp |
occupies the crown of the tooth, follows contour of crown larger than root pulp has pulp horns |
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how many surfaces does coronal pulp have |
6 surfaces M, D, B, L, O and the floor |
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radicular pulp |
root canals extend from the cervical region to the apex pulp tapered and conical |
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apical foramen |
opening of root pulp into the periodontium larger in max teeth if several apical canals exist the larges= apical foramen |
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accessory canals |
located on lateral sides of apical region |
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pulp contains |
large veins, arteries and nerve trunks surrounded by fibroblasts and collagen fibers embedded in an extracellular matrix |
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pulpal zones |
1. odontogenic zone: outermost zone, includes odontoblasts 2. cell free zone: Zone of Weil 3. cell rich zone: high cell density 4. parietal layer of nerves: located pulpal to cell rich zone |
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cells in pulp |
odontoblasts fibroblasts schwanns cells endothelial cells undifferentiated mesenchymal cells macrophages lymphocytes erythrocytes, leukocytes, eosinophils, basophils |
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theories of pulpal pain |
1. direct innervation 2. transduction 3. hydrodynamic theory |
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functions of pulp |
Inductive: Interaction with oral epithelium=tooth formation Formative: Dentin (odontoblasts) surround andprotects pulp Protective: In response to stimuli (heat, cold,pressure & operative) Nutritive: Carries oxygen and nutrition to thedeveloping/fxning tooth Reparative: Forms new dentin (reactionary/reparative dentin) |
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pulpal changes |
Decrease in size with age Appearance of dead tracts Reparative dentin under area of trauma Decrease in pulpal cells Decrease response to repair injury |
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describe the characteristics of the odontogeniz zone |
outermost zone, includes odontoblasts, appear most notably in coronal pulp |