Endodontic Overview Flashcards
what is endodontic disease
biofilm disease
what are the features of apical periodontitis
chronic polymicrobial infection
stimulation of host response
connective tissue disease
what is the clinical objective for RCT
remove canal contents
eliminate infection
what should obturation aim to do
coronal seal
timing of obturation
length
preparation
what are the special investigations used in endodontics
TTP
palpation
pockets
sensibility testing
radiographs
what fibres are stimulated for sharp pain
A fibres
what fibres are stimulated for dull pain
C fibres
what teeth can refer pain to the opposite arch
posterior teeth
what is normal pulp
symptom free and responsive to pulp testing
what is reversible pulpitis
discomfort when stimulus applied but inflammation should resolve after appropriate management
what is symptomatic irreversible pulpitis
vital inflamed pulp incapable of healing
spontaneous/lingering pain
what is asymptomatic irreversible pulpitis
vital inflamed pulp incapable of healing but no symptoms
what is necrosis
death of pulp needing RCT
what is previously treated
tooth has been endodontically treated with obturated canals
what is previously initiated
treated by pulpectomy/pulpotomy
what is normal apical tissues
not sensitive to percussion/palpation
lamina dura intact
PDL space uniform
what is symptomatic apical periodontitis
inflammation of apical periodontium presenting with pain on biting/percussion or palpation
what is asymptomatic apical periodontitis
inflammation and destruction of apical periodontium that is of pulpal origin
what is chronic apical abscess
inflammatory reaction to infection and necrosis with gradual onset and intermittent discharge of pus through associated sinus tract
what is acute apical abscess
inflammatory reaction to pulpal infection and necrosis characterised by rapid onset, spontaneous pain, pus formation and swelling of tissues
what is condensing osteitis
localised bony reaction to a low grade inflammatory stimulus seen at apex of tooth
what medical issues would contraindicate RCT
first trimester pregnancy
cardiovascular disease
cancer
diabetes
what dental findings would contraindicate RCT
periodontal problems
sub-osseous caries
unrestorable
sclerosis of canals
what are the treatment options for endodontics
no treatment with review
extraction
orthograde RCT
surgical endodontics
what are the success rates of orthograde RCT for irreversible and necrotic pulps over 10yrs
irreversible is 90%
necrotic is 80%
what is included in the consent obtaining process
treatment options and alternatives
prognosis
risks
opportunity to ask questions
agreeing on a plan
what are the functions of the pulp
nutrition
sensory
protective
formative
name some examples of injuries to the pulp
caries
cavity prep and materials
trauma
periodontal pathology
orthodontics
what happens to the dentine tubules as they approach the pulp and what does this mean
increase in number and diameter so permeability is greater
what are the problems with sensibility tests
they stimulate nerve fibres and dont indicate blood supply state
hard with multirooted teeth
how do you use the EPT
dry tooth
isolate
conducting medium
probe near pulp
patient holds handle of EPT
increase current and stimulation felt
what does a positive response with EPT mean
vital tissue in coronal chamber
no indication of reversibility
how do you do ethyl chloride
teeth dried and isolated
place cold object close to pulp horn
what does age do to the pulp
reduce size and volume due to continued dentine formation
how do you prevent pulpal damage
know tooth anatomy
avoid drilling into pulp
cavity close to pulp use sealers
cavity into pulp use direct pulp cap
what are the properties of CaOH
bacteriocidal
high pH stimulates fibroblasts
stimulates recalcification of demineralised dentine
neutralise pH from acidic restorative materials
what are herb schilders principles
create a continuously tapering funnel shape
maintain apical foramen in original position
keep apical opening as small as possible
what does mechanical preparation allow
create space to allow irrigating solutions and medicaments into the root canal space
what is the mechanical debridement process
preparation of tooth
access cavity
straight line access
initial negotiation
coronal flaring
working length determination
apical preparation
what size ISO file is needed for apical preparation
minimum ISO 25
what are the ideal properties of an irrigant
killing of biofilm microbes
detachment of biofilm
what are the properties of NaOCl
antimicrobial
dissolve pulp remnants and collagen
dissolves necrotic and vital tissue
what are the factors important for function of NaOCl
concentration
volume
contact
agitation
exchange
what concentration should NaOCl be
between 0.5-6%
what are the problems with NaOCl
effect on dentine properties
inability to remove smear layer
discolouration
ophthalmic injuries
apical extrusion
allergic reactions
what are the problems with chlorhexidine
cannot disrupt biofilms
risk of interaction with NaOCl
anaphylaxis
what is the cleaning and shaping protocol for the final rinsing sequence
3% NaOCl (30ml) for 10mins
17% EDTA 1 min
3% NaOCl final rinse
what are the symptoms of sodium hypochlorite extrusion
pain
swelling
ecchymosis
haemorrhage
neurological complications
airway obstruction
what is the classic presentation of sodium hypochlorite extrusion
bruising along course of superficial venous vasculature
what are the risk factors for sodium hypochlorite extrusion
excessive pressure during irrigation
needle locked in canal
loss of control of working length
larger apical diameters
anatomical factors
higher NaOCl concentration
what is the flow rate to avoid sodium hypochlorite extrusion
1ml per 15seconds
what is the management for sodium hypochlorite extrusion
stop treatment
keep calm
advise patient
explain material left canal
administer LA
get haemostasis
steroid medicament to reduce inflammation
cold/warm compress over next few days
review within 24hrs
advise analgesia
if deteriorating then OS or A&E
what are the guidelines for NaOCl use
pre-op radiograph
bib
eyewear
dam with oraseal
test with chlorhexidine
label syringes
side vented needle
dont fill it full
use index finger
use stopper
pass syringe behind patient
what do intracanal medicaments do
reduce inflammation or exudate and control root resorption
what is an antimicrobial paste and what is it used for
corticosteroid and tetracycline mix
for hot pulps
reduce pulpal inflammation
what does CaOH do in the canal
antibacterial activity
remove tissue debris
what is used for inter-appointment disinfection
CaOH paste
what is used for temporary dressings
GI cements
CaOH, small cotton wool, coltosol then GI
what is estimated working length
estimated length at which instrumentation should be limited
measure to apex and subtract 1mm
what is corrected working length
length at which instrumentation and obturation should be limited
apex locator for this
what is master apical file
largest diameter file taken to working length representing final prepared size of apical portion of canal
what are the different types of instrument movement
filing/reaming/watch-winding/balanced force/envelope of motion
what is watch winding
back and forward between 30-60 degrees
what is the modified flare technique made of
balanced force and step back
what is barbed broach good for
grabbing pulp
what is hedstrom file good for
re-RCT
how do you create a glide path
confirm straight line access
explore anatomy
coronal flare
irrigate and repeat
what is instrument separation due to
torsional stress
flexural stress
what is torsional stress
extensive instrument surface encounters excessive friction on canal walls
what is flexural stress
repeated cyclic metal fatigue
what is the cold lateral compaction procedure
place GP master cone to working length
some tug back
remove cone
dry with paper points
coat in sealer
place to working length
finger spreader
accessory cone
endo alpha to sever GP
endo plugger to plug coronal GP
when should obturation be undertaken
pain free
signs resolved
what is GP made of
GP
zinc oxide
radiopacifiers
plasticisers
what is the problem with cold lateral compaction
inability to obturate laterally and close voids between cones
what is warm vertical compaction
cone of GP in root canal and sever coronal bit
sealer passes into lateral anatomy
keep doing this until get to top
what is continuous wave obturation
fitted cone inserted and sever coronal part and then insert heated plugger into mass of GP in one continuous motion and remove which will leave an apical stop
what are the functions of a sealer
seals space between dentinal wall and core
fills voids and irregularities in canal, lateral canals and between points
lubricates during obturation
what are the properties of an ideal sealer
radiopacity
non-staining
no shrinkage on setting
advantage of ZOE based sealer
antimicrobial
advantage of GI sealer
dentine bonding
advantage of resin sealers
slow setting
good sealing ability
good flow
advantage of calcium silicate sealers
high pH
hydrophilic
biocompatible
no shrinking on setting
excellent seal
what is looked at on post obturation radiograph
length
taper
density
GP removed to CEJ
errors
what should be placed over the top of GP
ZOE
CaOH
RMGI
flowable composite
what is success defined as by ESE
RCT assessed after 1 year and absence of pain, swelling and other symptoms. no sinus tract. no loss of function. normal PDL
what is an uncertain outcome
radiographic changes remain same size or has only diminished in size
what is unfavourable outcome of RCT
signs and symptoms of infection
lesion appeared after treatment or pre-existing lesion increased in size
root resorption
what are the pre-op factors affecting success
non-vital with or without periapical lesion
what are the operative factors affecting success
filling extending to within 2mm of apex
no extrusion of obturation
good coronal restoration
patency
no perforation
EDTA rinse
no mixing of CHX and NaOCl
what are the biological reasons for failure
persistent intra-radicular infection
extra-radicular bacteria
non-microbial agents
cholesterol crystals
foreign body reactions
scar tissue healing
how do you assess restorative prognosis
check for fractures
assess remaining amount of tooth structure
get good seal
how do you remove insoluble resin
ultrasonics
how do you remove GP
hand files and solvent
reciproc
what is the protaper retreatment protocol
lowest speed that effectively engages material
D1 into GP until obturation material removed from coronal third
auger obturation from middle with D2
remove from apical third with D3
what is the reciproc retreatment protocol
remove bulk of obturation material in coronal third with heat
remove obturation material in body of canal with R25
determine working length and remove obturation material in apical third
increased apical enlargement with R40 and R50
what do solvents do to tubules
leaves smear of GP on them and obstructs them
how do you avoid perforations
inspect external surfaces
think where you8 are in tooth
knowledge of anatomy
measure radiograph
Dg16 and rubber stopper as depth gauge
what are the complications of instrumentation
blockage
ledges
apical damage
perforation
fractured instrument
what is blockage
dentine debris getting packed into apical portion of root
what is a ledge
internal transportation of canal when working length too short
what is apical zipping
over-enlargement on outer side of curvature and under-enlargement of inner aspect at apical end point
what is apical transportation
transportation of apical foramen fails to provide resistance for packing of GP so it is overextended and poorly filled
how do you diagnose a perforation
persistent bleeding into canal
multiple radiographs
electronic apex locators
dental operating microscope
what does the prognosis of perforation depend on
location
time elapsed
size
periodontal irritation
material used for repair
what are the issues with access
too big/small
roof of pulp chamber not removed properly
perforation
what are the issues with mechanical preparation
blockage
separated file
ledge
how do you avoid blockage
dont skip files, dont force files, ensure file is passive prior to moving to bigger file
recapitulate and patency file and irrigate
what are the issues with obturation
too short/long
voids
too much GP in pulp chamber
GP in other canals
how do you avoid separating instruments
know limits of instrument
pay attention to rotation degrees
stay focused
lubricate canal
how do you avoid obturation not being the right length
pre-op radiograph
apex locator and reference point
