Introduction, Instruments, Setup Flashcards
What is endo
branch of dentistry dealing with morphology, physiology, and pathology of pulp and periapical tissues
At eruption, pulp chamber reflect external form of…
enamel
With time, what happens to pulp chamber?
steady readuction in size on all surfaces from secondary and tertiary dentin
What is a dead tooth?
extracted
doing RCT removes bacteria from what zone?
zone of infection
What are the 4 zones?
infection, contamination, irritation, stimulation
4 functions of dental pulp
FOrmation of dentin
defense of tooth (tertiary dentin)
nutrition of dentin
innervation of tooth
Odontoblasts secrete what?
type 1 collagen
Dentin matrix proteins (DPP DSP)
Dentin organic/inorganic/water comp
70% in
18%org
12%water
Primary, Secondary, Tert dentin?
1 - formed before eruption
2 - formed after eruption
3 - irritant to pulp
most numerous cell in pulp?
fibroblasts
Pulpal circulation is special because?
- terminal circulation
- enclosed - no space for swelling
- no collateral circulation
What types of nerve fibers are in the pulp?
A-delta and C
A vs C fibers: Myelin Diameter Central/Periph Threshold for stimulation Stimulation assoc with what?
A: Myelinated Large Peripheral Low threshold Stimulated without tissue dmg
C: non-myelinated small central high threshold stimulated when dmg
Why do A-delta fibers have shorter survival time?
lower resistance to oxygen depletion
Hydrodynamic theory says dentinal fluids cause pressure changes where?
dentin, predentin, odontoblastic layer
5 Layers of pulp
odontoblastic layer cell free zone cell rich zone Plexus of Raschkow Central Pulp Zone
predentin is?
newly formed dentin
Odontoblastic zone is what?
palisading layer of cells whose processes extend into tubules
Tree trunk appearance lines called what?
calciotraumatic
Cell free zone has high…
capillary density
C fibers present where?
Plexus of Raschkow and Central Pulp Zone
Venous drainage from teeth (3)
Pterygoid plexus, cavernous sinus, internal max. vein
What do neuropeptides do?
role in neurogenic inflammation
control bloodflow
regulate later stages of repair
What neuropeptide produced in trigeminal nerves?
Substance P
Cascade of substance P?
c-fibers release –> mast cells release histamine –> increase vascular permability and BP in pulp
Substance P levels greatly increase when?
irreversible pulpitis or mechanical pulp exposure
Why are some pts more resistant to pain?
diff levels of substance P
What happens with mild pulpal irritation?
Slight increase in cellularity into cell-free zone, increase in capillaries
What happens in moderate pulpal irritation?
continued increased cellularity and capillaries, odontoblastic layer disrupted and nuclei displaced into tubules
What happens in severe pulpal irritation?
Abcess, necrosis, odontoblastic layer destroyed, predentin missing
What structure in dentin most permeable to entry into pulp?
dead tracts
Even before bacteria actually reach pulp, it is inflamed why?
bacterial toxins
When do irreversible inflammation insue (depth)
0.5mm remaining dentin
Has degree of pulpal inflammation been accurately correlated with…
depth of dentin exposed?
speed at which pulp reacts by creating reparative dentin?
no
yes
How does pulp resist inflammation?
laying down reparative dentin
Repeated irritation –> ?
irreversible
Correlation between pulpal status and clinical picture?
NO
Internal resorption is what and what causes it?
resorption of dentin from inside, linked to trauma
External resorption is what? LInked to what?
resorption of dentin from outside pulp, linked to trauma or ortho
When is a root canal necessary?
(distance to pulp)
(what kind of teeth)
(consideration for crown)
- 1mm from pulp
- traumatized teeth
- not enough tooth structure for crown
4 “main” instruments
- mirro
- explorer
- locking pliers
- spoon excavator
cold testing causes what movement in tubules? Should have response within how long?
outward, 15s
Does number in electronic pulp testing indicate level of inflamation/
no
Burs for access? Which for anterior/molar
2,4 round, 44C and F diamond
2 for ant
4 for molar
Which hand files do we use?
Stands for?
Made by twisting a?
Used in what movement?
K files
Kerr
square
1/4 turn
ISO size colors:
Purple White Yellow Red Blue Green Black
starts from 10 goes up by 5
Diameter vs # of files?
a 10 files is 0.1mm at apex
What does taper mean?
for every millimeter up the file, the diameter increases by the amount of the taper
What orifice openers do we us?
gates glidden 4,3,2
Preflaring canals is good why?
gets a more accurate determination of working length
Profile series 29 sizes?
Red - 0.216
Blue - 0.279
Green - 0.360
Brown - 0.465
Landed vs Non-landed?
Landed are slower, safer, less aggressive
Non-landed more prone to breaking
What is intracanal medicament? What do we use?
Kills bacteria in canals between visits
Calcium Hydroxide Ca(OH)2
What does calcium hydroxide do?
pH raised to 12.5…
- Cell membrane dmg
- Protein denaturation
- DNA dmg
Obturation phases of gutta percha?
115f/46C degrees transition from beta to alpha phase, amorphous at 130-140F/54-60C
What is the sealer made of?
Zinc oxide eugenol?
Sealer purpose?
fills in spaces around GP
Most commonly used temp material in endo is?How much needed for successful seal?
Cavit, need 3.5mm
