Dental Pulp and Caries Flashcards
how does dental pulp evolve
goes through the same stages as the rest of the tooth- goes through embryogenesis
what are the stages in dental pulp embryogenesis and what happens in each
-cap stage: dental papilla
- bell stage: primitive pulp, contains capillary development
what does the mature dental pulp consist of
loose CT
what is mature dental pulp derived from
neural crest (ectomesenchymal) cells
where is the density of cells in dental pulp get higher
towards the dentin
what is the odontogenic zone cell layer and is it cellular rich/dense
-odontoblastic cell layer
- cellular rich/dense
what does the odontogenic zone contain
- cell-free zone of Weil
- Cell-rich zone
- Raschkow’s plexus
what cell layer makes up the pulpal core and is it cellular/dense
-fibroblastic layer
- not very cellular or dense
what does the pulpal core contain
-type 1 and 3 collagen
-extracellular matrix
- blood vessels
- nerve tissue
what are the functions of the pulp
- embryonic induction (as tooth continues to develop, presence of pulp in the IEE helps to stimulate further development of the enamel organ)
- formative: has the cells necessary to orm certain mature structures within the tooth
-protective
-reparative
what are the cells in the pulpal tissue
-fibroblasts
- odontoblasts
- undifferentiated mesenchymal cells
- macrophages and dendritic cells
-blood vessel related cells (endothelial and pericytes)
- neural related cells (schwann cells)
- lymphocytes (for immune response)
what is the majority of cells in the pulpal tissue
fibroblasts
what percentage do macrophages and dendritic cells make up in pulpal tissue
8%
what makes up the collagenous extracellular matrix of pulpal tissue
mostly type 3 collagen (25-32%) (and 1,4,5) via odontoblasts
what makes up the non-collagenous extracellular matrix of pulpal tissue
-proteoglycans, glycosaminoglycans, phosphoproteins, glycoproteins
-y-carboxyglutamate-containing proteins (BMP,FGF,EGF< DMP), stimulate growth and maturation of both ameloblasts and odontoblasts
what are most nerve endings in pulp for
pain
-(few for vasoconstriction/dilation)
what does the trigeminal nerve in the pulp give off free nerve endings as sensory afferents for
-pain
-mechanical (pressure)
- thermal
-tactile
what ganglion is for pulp
superior cervical ganglion
what makes up the superior cervical ganglion in pulp and what is their function
sympathetic branches, primarily vasomotor fibers to pulpal blood vessels and function most in vasoconstriction
what does pulp nerve tissue contain
myelinated and non-myelinated nerve axons
what do axons in pulp nervous tissue branch into
the subodontoblastic layer as Raschow’s plexus into the odontoblastic cell layer and some fibers enter into the dentinal tubules. forms before the full formation of roots
how many branches does each nerve fiber branch into the plexus
at least 8
what do most nerve fibers terminate in the plexus as
free nonmyelinated nerve endings (C-fibers)
where are schwann cells located and what do they do
functions in myelination in the PNS, allows for faster nerve conduction
describe A-delta fibers, their conduction velocity, size and function
-majority of myelinated pulpal nerves
-fast conducting
-diamter range of 1-6 um
- associated with sharp, localized pain
describe A-beta fibers and size
-1% of myelinated pulpal nerves
-diamter range of 6-12 um
describe C-fibers fibers and size and function
-nonmyelinated
-diameter range of 0,4-1.2 um (smallest)
- associated with dull,diffuse pain
what are the neuropeptides and NTs inside the dental pulp
- calcitonin gene related peptide (CGRP)
- Substance P
- epinephrine
- NE
- dopamine
-endorphin
what does CGRP do
vasodilation, stimulates fibroblast cell division
what does substance P do
vasodilation, stimulates fibroblast cell division,
what does EPI do in dental pulp
vasoconstriction via arteriole smooth muscles
what does NE do in dental pulp
sympathetic vasoconstrictor
what does dopamine do in dental pulp
vasoactive or a precursor of epinephrine
what does endorphin do in dental pulp
silences of nociceptor (pain)
what is the distribution of nerve axons and blood vessels in intratubular dentin
-pre-dentin will have more nerve axons
the more mineralized you get ____
the less nerve axons you will have
as you are more coronal there is more ____
branching and more nerve activity
what makes up pulp horns
-27% pre-dentin
-11% mineralizing front
-8% dentin up to 100 um
what makes up remaining crown
-14% pre-dentin
-6% mineralizing front
-2% dentin up to 100 um
what makes up the root
-11% pre-dentin
-0% mineralizing front
- 0% dentin up to 100 um
describe arterioles
diameter of 50-100 um, thicker
describe venules
diameter of 100-150 um. thinner
describe capillaries
anastomoses deep to the odontoblastic layer
where are capillary loops dense and less dense
dense in the coronal and pulp horn regions and less dense in the radicular pulp
describe changes in blood vessels due to age
exhibit changes like cholesterol plaque- if severe can result in pulpal hypoxia due to vessel strangulation
describe fenestrated capillaries and what are they important in
with holes, allows for serum/fluid movement. important in inflammatory response and swelling: serum/tissue fluid to leaks out of capillaries (as a response) into the surrounding tissue causing the swelling
describe continuous capillaries
lacking holes
what is pulpal fibrosis and what causes it
-shrinking of the pulp
- occurs with increasing age or persistent low grade injury (bruxism, thermal insult, multiple restorations on single tooth)
what are diffuse calcifications
irregular calcified deposits along collagen fiber bundles or within blood vessels resulting from chronic low grade inflammation/insult to the tooth
what are pulp stones/denticles
classified as either free, attached (in wall) or embedded (in pulp). do not cause pain or issues, only an issue during RCT access
what are true pulp stones
contain dentinal tubules
what are false pulp stones
feature concentric layers of calcified tissue but are void of dentin tubules
what is abscess
dense aggression of neutrophils and macrophage and other inflammatory cells within CT undergoing liquefactive necrosis (cell structure breaks down and tissue becomes liquified)
what are vacuolated macrophages
consume dead tissue “clean up the mess”
what are syncytial macrophages
multinucleated, resorb dentin adjacent to inflammed pulp
what is pulpal abscess
active inflammatory process. will destroy soft tissue and mineralized tissue if left there
what does pulpal abscess lead to and why
pulpal necrosis due to inability of pulpal tissue to swell, the increasing edema and inflammatory cell infiltration
what is pulpal necrosis
inflamed pulp cuts off its own blood supply, leading to tissue death
what are the symptoms of pulpal necrosis
clinically expressed with pain and periapical necrosis (seen as radiolucent near apex of root on radiographs) of the PDL and associated alveolar bone
what is the treatment for pulpal abscess
incision and drainage (I and D) followed by endodontic therapy
what is diffuse cellulitis
when pulpal abscess enlarges so much to where it is involving airways
