endodontics Flashcards
goal
1) treatment of periraadicular periodontitis
2) elimination of infected or inflamed tissue
what encompasses endodontic treatment
1) non surgical
- vital pulp therapy
- pulp capping and pulpotomy
- RCT
2) surgery
vital pulp therapy
1) make sure the pulp that is present remains healthy so PA tissues are also healthy
how to decide what treatment
1) status of the pulp
- inflamed or dead
- if inflamed reversible or irreversible
2) history of damage to the pulp?
anatomy
1) coronal pulp
2) radicular pulp
3) pulp horns, chamber, canals, apical foramen, lateral accessory canals
mean volume is 0.02 cc
- low compliance environment
- amount of inflammation it can withstand is limited
- pulpal pain is very severe to humankind
minor apical diameter
1) where pulp ends
2) stop here with RCT (minor apical diameter)
3) only detect with apex locator
anatomy of the dental pulp
1) pulp horn
2) pulp chamber
3) radicular pulp
4) lateral canal
5) CEJ
6) apical foramen
histology of the dental pulp
1) organized into 4 zones
- odontoblastic
- subodontoblastic
- cell free
- cell rich
- pulp proper
cells of the pulp
1) formative
- odontoblasts and subodontoblasts
2) reparative
- fibroblast, stem cells
3) defense
- macrophage, dendritic, T cells, mast cells
odontoblasts
1) form dentin, predentin, matrix
2) active as long as tooth is alive
3) post mitotic cells
- lay some amount of dentin over lifespan (secondary dentin)
4) major damage
- reactionary / tertiary dentin is by subodontoblastic cells
5) also secrete organic content
- collagen, non collagenous protein
- type I most common
- proteins common between dentin and bone
- phosphophoryn specific to dentin
6) also make enzymes
hoehl’s cells
1) vital pulp must be present for dentin formation
- aka blood flow
odontoblast structure clinical relevant
1) most odontoblastic processes terminate in DEJ
2)dentin and pulp form one structural unit (dentin pulp complex)
3) odontoblast bodies are in close proximity (tight junction)
4) permeability of dentin will be increased making it easily for noxious stimuli to enter
- hydrodynamic effects (ex. extreme cold sensitivity)
dentin pulp complex
1) strong functional association
microbes or toxins enter the pulp
1) endotoxin and exotoxin
2) if caries goes into dentin, do a pulp test and make sure the pulp is healthy before restoration
3) dentin forming repair and immune mechanisms
stromal fibroblasts
1) fibroblasts and stem cells cause repair
2) most prevalent type of cell in the pulp organ
3) role in wound healing and pulp repair in regeneration
- collagen and noncollegenous protein
4) dental pulp stem cells
- mesenchymal cells
- differentiate into preferred cell type
- ex. nerve, fat, bone, etc.
macrophages
1) defense response and recognizes irritant
- pro inflammatory environment
2) phagocytose foreign bodies
3) in skin infections, bacteria enter macrophages and can escape phagocytosis
- treatment failure
dendritic cells, lymphocytes, mast
1) T immunity
2) mast cell are typical in chronic inflammation
- only see in this kind of pulp
- hemorrhage a lot
- heparin is anticoagulant produced by the mast cell
- more bleeding
ECM
1)collagen
2) glycosaminoglycans
- proteoglycans, hyaluronan
3) prevent spread of inflammation
- localizes it to zone
4) can be degraded by MMP
collagen
1) primary component of pulp tissue
1) type I and III 26-32% dry weight
2) type i from odontoblasts, III from fibroblasts
3) large and tight bundles toward apical third of root canals
von korff
1)extend from odontoblasts into dentin matrix
- type III
clinical relevance
1) pulp has largely protein constituents
2) dissolve pulp during RCT
- high PH
2) non specific proteolytic agents (sodium hypochorite)
- dentin also has collagen
3) pulp preservation
- vital pulp therapy
- using bioactive materials that stimulate pulp cells
- dentin formation
pulp vitality vs pulp sensibility
we measure sensibility
afferent neurons
1) sensory impulses
- thermal, mechanical, chemical ,electric
2) perceive all as pain
efferent autonomic neurons
1) modulating microcirculation, inflammation, etc
sensory nerve fibers
1) a fibers
- myelinated nociceptor
- 90% Adelta, Abeta
- sharp rapid pain
- larger diameter
2) C fibers
- unmyelinated
- burning, aching
- smaller diameter
a delta
1) pain, temp, touch
2) stimualted during dentinal tubule movement
a beta
1) pressure, touch
2) stimulated during dentinal tubule movement
if you cut a cavity without anesthesia, which is stimulated?
1) both a delta and a beta
- respond to pressure, touch, pain
complaining on drinking cold drinks
1) a delta
- temperature
spontaneous, severe and unbearable pain
1) C fibers
- burning, aching, less bearable
2) pulp has poor repair
- need RCT
cutting cavity without water coolant
a delta (heat), a beta
plexus of raschkow
1) A fibers emerge from schwann cells and branch repeatedly
2) dentin - devoid of sensory nerve fibers (except dentinal tubules)
pulp microvasculature
1) pulp vitality = blood supply
2) high blood flow (40-50 ml/min/100 g pulp tissue) > other oral tissues and skeletal muscle
pulp microvasculature clinical implications
1) any increase in tissue pressure will cause pain
2) firm and resilient CT limits inflammation to a zone
- until it reaches a threshold
3) lack of true collateral blood supply
- healing capabilities is less than other organs
4) easy spread of infection from apical foramen into PA tissues
5) vascularity decreases with age
neural - vascular connection
1) neuropeptides
- CGRP (inflammation and wound healing)
- substance P
- neurokinin A
neural-vascular connection clinical relevance
1) decreases neuropeptide production directly with LA
- less pain
2) indirect action with vasoconstriction
blood flow for inflamed pulp
1) lying down can cause severe pain (inflamed pulp)
- irreversible pulpitis
2) increase in peripheral blood flow, intrapulpal pressure
