Endo revision notes Flashcards
Purpose of dental dam
tp retract and protect soft tossues
to reduce operator stress
prevent the pt from rinsing
prevent bacterial contamination
to prevent inhlation of insturments and materials
Ideal end point in RCT
CEJ/apical constirction
Recapitualtion
the introduction of smaller instruments into the canal to remove any debris present and to keep the canal clean
Pre op radiograph
to assess for peri-raiducalr pathology
canal calficiation
root -size, shape, number
pulp horns
the pulp chamber
the localtion of canals
Patency
communication between the root canal and peri-radicular tissues by passing small files beyond the apical constriction
Design objects in endo
create a continusally funnellnig shape
maintain the apical foramen
keep the apical opening as small as possible
Radigraphs used in rct
cwl radiograph
ppre and post radioraphs
maf rafigraph
eastimated working length
measured from a radiograph and is taken from a conronal refernce point to the apex of the tooth
Corrected working length
it is from a predefined coronal point to the apical terimnus of a tooth 1. radipgraph, 2. apex locator, 3. papper point length
Master apical file
the final file that is used in the apical portion of the canal to working length and is shaped and ready for obturation
GP consisits
GP (15%)
Radiopacifier (5%0
Plasticieser (15%)
zinc oxide (65%)
MTA
mineral trioxdie aggerate
used - root tips for apicectomy, root fracture repairs, internal root reosprtion, pulp capping
advantages - biocompatible, relases ca, alkaline ph, antibacterial
disadvangtages - long setting time, high cost, discolouration
Aims of NaoCl
disinfect the canal
to dissolve oragnic debris
to flush out debris
to lubricate insturments during root canal treamtnet
Factors for NaoCl function
volume
contact
exchange
chemical agigitation
concentration
NaoCl conc
0.5-6% - 3% the best
Problems with NaoCl
does not remove the smear layer
discolouration of fabrics
allergies
can cause eye damage
apical extrusion leading to tissue necrosis
Smear layer
a layer of inorganic debris and rganic material formed during cancl prep
it prevent sealer penetration
How to remove smear layer
17% EDTA - chealating agent that removes smear layer and opens dentinal tubules
Guidance for use for naocl
use a pt bib to prevent disoclouration of fabric
eye protection for pt
pass the syring behind the pts head
label all syrings correctly
test the naocl site with chx before using to ensure correct seal
use rubber dam
use side vented 27mm gauage 3ml syringe
depress plunger wtith finger rather than thumb
ensure only fill the syring 2/3rd full
correct concentration of naocl
use a rubber stop 2mm short of working length
avoid in tight canals and have a good opening
Symptoms of naocl extrusion
pain, swelling, neurological signs, heamoragge, airway obstuction, brusing
Risk factors for extrusion of naocl
concentration
needle locked in the canal
excessive pressure
loss of control of working length
proximity to sinus
NaOCl extrusion what to do
stop what you are doing imeediately and inform the pt of what has just occured
acheive heamostatis in the tooth and canal and place an intermedicament dressing
do not obturate or seal the canal
if small then advice pt cold compresses for first 24hrs, warm compressers thereafter, anaglesics for pain, anibiotics if only necorsis and spreading infeciton
review pt in 24hrs
if larger then may require advice and trasnfer to local max fax unit
document the incident in the pt notes and the accident incidicent book
Function of selaers
to lubricate during condesation
to fill voids and irregularies between GP and the canal
seals between dentinal walls and core
Properties of a sealer
biomcompatible
radiopaque
dimensially stable
does not dissolve in oral tissue fluids
can easily be removed from root canal if required
slow setting
no shrinkage
no staining
antibacterial
insoluble
ZOE sealer
antimicrobial but realses free eugenol which can be an irritant
GI sealer
minimal antibacterial activity
diffierlt to remove if required
increased solubility
Resin sealers
slow setting
good flow
Calcium silicate sealer
biocompatible
easy to use
quick set
non resosorbale
excelleing selaing abilities
Aims of root canal fillng
prevents the intrioduction of microgoransisma dnfluids into the canal
blocks any remaining micro-ogranisms in the canal
blocks the apical formaina, dentinal tubules and accessory canals
Anti - microbial paste
odontopaste/ledermix
contains both tertracyline and corotocosteriod
aids in reduction of pulpal inflammation
Ns CaOH
alakaline ph 12.5 so antimicrobal
effective in removing tissue debris
thin so won’t reduce striength
Ns CaOH used for
inter medicament sealer
pulp capping
interal resorption
apical resoprotption
root fracture
open apex and immature tooth
larger perapical lesions
Beofre tx failures of endo
pooh oh
missed diagnosis case selection
during tx failures for endo
missed canals
iotrogenic damage
infeefftive cleaning, filling, shaping
after tx failures for endo
poor oh and caries develops
damage when placing post
leakage of conronal restoration
Failures of RCT
re infeciton
missed canals
perforation of root
loss of conoral seal
not adequate patenct
communcaiton of canal
necrotic material left
Extra radicular features of failure
radicular cyst present
root fracture
Tx options for RCT failure
retreatment rct
peridaciular surgery
do nothing if aymptomatic
XLa
Success for RCT
GP is withing 2mm of apex
well conensed, no voids or irregularites present
good cornoal resotration
Radiograph follow up
1 year and for 4years after
Periradicular surgery
apicectomy
surgery which onvovles removing only the root tip of an infected tooth - about 3mm
leaves the RCT intact
Used - when peri-radicular infection coninues, cannot retreat rct, cyst or infection present, iotrogenic damage (perofration)
Endo retreatment
use protapers D1,2,3
for resin selaers - ultrasonic
for GP - protaper D and ecalptus oil
soluble paste - protaper with solvent
Special investigations for diagnsosi
percussion test - positive means inflammation
mobility test
sensbility tests
occlusion - occlusal trauma intitates periadicular periododntitis
Test cavity by drilling with no la
Perio probing
transilliumniation
radiogrpahs
cusp loading test - tests for cracked tooth
sinus tract explration
Puliptis
inflammation of the pulp
Reversible pulpitis
inflammation of the pulp which lasts for only a few seconds and is to do with cold, sweet things, sharp quick shooting pain
Irreversible pulpitis
inflammation of the pulp which lingers for a period of time onces the stimulus has been removed
the vital inflammaed pulp cannot heal
referred pain
Pulp necrosis
death of the pulp - due to trauma or calcification
Don’t pulp cap
non vital teeth
pa path present
irreversible pulpitis
large exposure
Main causes of injury to pulp
bacteria present due to:
-caries
- perio disease (dentinal tubuls, furcal and lateral canals)
- cracked teeth
- trauma
- erossion, attrition, abrasion (dentinal tublues)
-developmental anomalies
Apical periodontitis or periapical periodontitis
inflammation of the tissues surroudn the root of a tooth - casues infection in root canal system
inflammation of periradicular tissues
pressure to biting, TTP, palaption
PDL can sometimes be widening
Chronic peripapcal abscess
inflammatory reaction to pulpal infection and necrosis
gradual onset, little discomfort and pus through sinus or perio pocket
Acute periapical abscess
inflammatory reaction to pulpal infection and necrosis
rapid onsent, pain present, pus, swelling, maliase, fever, lymphadenopathy, TTP
Indirect pulp cpping
when the pulp of the tooth is not quite exposed but close
use either calcium silcate or calcuim hydroxide with rmgic/gic and resotration
Direct pulp capping
<24hrs <=2mm exposure of pulp
Partial pulpotomy
pulp expose >=2mm, bleeding and inflammation cannot be stopped and acheieved
Full pulpomty
large portion of pulp exposed nd bleeding cannot be achieved
if heamostasis continues may need to reusslt in pulpectomy
Follow up in endo cases
6months clincially
1 year radiographically
Obturation
warm vertical condensation
lateral condesation
carrier based
thermomechanical compaction
PRevention of fractures on teeth
minimise internal wedging forces
minimalr removal of intraradiuclar dentine
avoid use of posts where possible
Types of tooth fractures
craze lines
cracked cusp
crack tooth
split tooth
vertial root fracture
Craze lines
seen on the enamel of teeth
no tx required
Cracked cusps
occurs on 2 aspects of cusp by crossing the marginal ridge either buccal or lingually
fracture of crown going subinginvally
Tx -removal of the cusp and replace with onlay/crown
Cracked tooth
incomplete fracture from crown subgingivally marginal rdige and proximal surfaces
more centred and apical than a cracked cusp
likley to casue PA path and pulpal issues
Tx = potential rct
Split tooth
crack on tooth that extends subgingivally
complete fracture
occurs after the evoluation ofa cracked tooth
Tx - mainly xla unless can remove segment
Vertical root fracture
complete or incomplete fracture going subingvally and then cornally
Tx - xla or potentially hemisection
How to prevent fracturing endo insturments
allow a good striaght line access
good vision and magnification and illumination
use files in correct sequence
aviod using files on numerous occasions
do not put too much force or pressure in the files
What are the main cuases of failure of rct
bacterial contamination
inadequate disinfection
Intrument fracture due to
small files
operator inexperience
poor root morphology/ curvatures
torsional or flexure fracutre
number of times files used
technique used
Why carry out periradiuclar surgery
if failed RCT before
biopsy of a periapcal path - radicular cyst
external root resoprptioin
ramage of damage - perforation
management of peradicular infection
direct inspection of fracture
retirval of fracture insturments
File retrield procedure
apical 1/3 - do not achieve retirieval - obture to fractured insutrment and monotr
middle 1/3 - try to bypass and if not obture to fractured insturment and potential for surgery
cornal 1/3 - remove fracture intrument with minimal removal of dentine
If sepration occured before instrumentaion or disinfection
bypass fracture and if not then place interm ed caoh and wait 2-4weeks and then obturate adn follow up
Internal inflammatory root resoprtion
non vital pulp resorbs the internal surfaces of a root
balloning appearnace intrenal and root surface intact
pink spot may be present on tooth
Tx - mechanical and chemical debrdiement, ns caoh placed for 4wks and then obturate
External inflammatory root resoprtion
intiatited by PDL damage which is maintained and propgated by necortic pulp tissue
root surface indisitnct and the intact tramlines of internal canal
Tx - chemical and mechanical debridment, nscaoh placed for 4wks then obturate
External cervical root resoprtion
resoortpio of root surface that occurs cervically on the root
parallel lines present and apple core appearnaced
Tx - monitor, XLA, interal repair and endo
External replacement reosprtion (ankylosis)
resoprtion of tooth sutructure which inturn tunrns to bone
loss of PDL and lamina dura
occurs after trauma - avulsion, luxation, intrusion
Tx - no treament possible exepcet decorniate to ACJ if infra occlusion and monitor
Root resoprtion occurs due to
truama
bleaching
bruxism
ortho
exfoliation of decidous teeth
impacted teeth
posts indicated
in premolar teeth
when 1/2 marginal ridges are lost on tooth
Choice of post
root morphology
internal canal antomy
remoaing coronal dentine
Post crietira
4-5mm of GP present at the apex of the tooth
no more than1/3 the diameter at the root of the tooth
crown to post ratio 1:1
2/3rds the root length
2mm of ferulle present
2mm supra ging tooth remaining
1mm of coronal dentine present
avoid lower incisors and curved canals
Ideal post
parallel sided - avoids wedging and reduces root fracture
cement retained
non threaded - less stress on tooth, howver is less retentive
not rotated
Parallel sided
requires the removal of more dentine to be removed so risk of peroforation
Tapered sided
less dentine to be removed
small tapered roots
HOWEVER
more stress into root so incrsaed root fracture
Serrated
increases root surface area for retention but does not increase stress
Post removal
USS
Masseran kit
Eggler post remover
Mosquuito forceps
Sonic scaler
Failure of posts
fibre - decementation
carbon or metal - due to root fracture due to stress
Perio
Caries
Vertical root fracture
Root resoprtion
Decementation
Perforation
endo failure
post or core fracture
Nayyar core
uses amalgam or compiste
used when loss of both marginal ridges and the pulp chamber small
2-3mm of g pis removed in the coronal portion
Ferrule
2mm of ferrule remaining to increases resitance from fracture due to lateral forces
Cores
composite - mainly for firbe osts, good aethetics, bonds to tooth strucuture, however mositure sens and tech sens
Amaglam - easy prep, poor aesthetics and requires retnetion as can’t bond to dentine adn takes 24hrs to set so dealy in tx
GI - bonds to dentine adn relases fluoride, but it is weak and absorbs water and expands
Material
Ceramic - zirconia
Cast metal - risk of corrision, ppor aesthitcs, radiopaque, root fracture
fibre posts - glass, quartz, carbon - do not use if not enough ferrule as risk of root fracture
Ledge
a step made within a canal due to stopping the file too short of the working length
Zippeing
a tear drop shape created in apical 1/3 of the wall - due to overextending passed the apical forman or large files
Transportotion
creation of a new pathway - due to excessive force during instrumentation
