Endodontics Flashcards
4 ways to dx vertical root fracture
- transillumination
- wedge and x-ray
- perio defect
- tooth slooth
vertical fracture through ROOT has __ prognosis unless you can remove the segment and ___ and ___ are performed
HOPELESS prognosis unless GINGIVOPLASTY and ALVEOLOPLASTY
tooth with vertical root fracture has ___ prognosis
POOR prognosis
most vertical root fractures are caused by?
using too much CONDENSATION FORCE during OBTURATION
anterior tooth fractures are usually caused by
accidental trauma
cracked tooth syndrome is characterized by
sharp, brief pain occurring unexpectedly when pt is chewing
3 types of flaps
- submarginal curved (semilunar)
- submarginal triangular and rectangular (ochsenbein-leubke)
- full mucoperiosteal (full thickness)
submarginal curved flap (semilunar)
half moon shaped, curved horizontal incision in mucosa or attached gingiva with concavity towards apex
NOT for anterior tooth root-end surgery
disadvantages of submarginal curved flap (semilunar) (4)
- limited access and visibility
- tearing of incision corners
- incision over bony defect -> scars
- incision limited by attachments (frenum muscles)
submarginal triangular and rectangular flap (ochsenbein-leubke)
requires 4 mm attached gingiva, healthy periodontium
scalloped incision in attached gingiva with 1 or 2 vertical incisions
LESS risk of incising over bony defects
no post-surgery gingival recession
CAN be indicated for root end surgery on anterior tooth
disadvantages of submarginal triangular and rectangular flap (O-L)
hemorrhage and scarring
advantages of submarginal triangular and rectangular flap (O-L)
better access and visibility > semilunar flap
NOT better than full mucoperiosteal flap
full mucoperiosteal (full thickness)
allows max. access and visibility
raised from gingival sulcus (elevating gingival crest + interdental gingiva)
outline precludes incisions over bony defects -> allows perio tx (curettage, SRP, bone re-shaping)
CAN be indicated for root-end surgery on anterior teeth
disadvantage of full thickness flap
difficult to reposition, suture, alter
gingival recession possible
electric pulp tester has HIGHER current if
tooth has CHRONIC PULPITIS
EPT checks vitality by
stimulating nerve endings with a LOW CURRENT and HIGH POTENTIAL DIFFERENCE in voltage
EPT results
- acute pulpitis = ___ current
- chronic pulpitis = ___ current
- hyperemia = ___ current
- pulp necrosis/abscess = ___ current
- acute = LOWER than normal (acute inflammation lowers pain threshold)
- chronic = HIGHER than normal
- hyperemia = LOWER than normal, but HIGHER than (1) acute pulpitis
- necrosis/abscess = NO response
EPT gives false (+) in these circumstances
- pus-filled canal
2. nervous pt
EPT gives false (-) in these circumstances
- recent trauma
- insulating restoration
- gloves
EPT also not reliable in these circumstances
- secondary dentin deposits
- moisture contamination
- immature tooth (open apex)
- pt taking analgesics
SLOB rule
lingual CLOSEST to cone
buccal FARTHER from cone
if xray taken from MESIAL, the lingual surface (ML canal) will appear more ___ than the buccal surface (MB canal) which appears ___
ML canal more MESIAL
MB canal appears farther DISTALLY
if xray taken from DISTAL, the lingual surface (ML canal) will appear more ___ than the buccal surface (MB canal) which appears ___
ML more DISTAL
MB more MESIALLY
Dx tests for recently traumatized teeth (4)
- soft tissue exam
- hard tissue exam
- xray
- observe adj. and opposing teeth for injury
Dx tests CONTRAINDICATED for recently traumatized teeth (2)
- EPT - pulp undergoes temp. paresthesia
2. percussion - painful
radiation safety
- stand 6 ft away, 90-135 deg. to beam
- FAST E-speed film
- 70 kVp or higher (higher = lower dose)
- collimation < 2.5 in.
- use lead apron and thyroid collar
- max. dose = 50 mSv/yr
PULPOTOMY indicated for (4)
- cariously exposed primary teeth with healthy pulp
- trauma or carious exposure of immature permanent teeth
- instead of EXT when you can’t RCT
- emergency for permanent teeth with acute pulpitis
can you do pulpotomy on fully developed permanent teeth?
NO. Not successful - it’s only temporary tx
if doing pulpotomy on immature permanent tooth and bleeding isnt controlled you:
amputate at more apical level
uncontrolled bleeding is a sign of
inflamed pulp tissue
for successful pulpotomy radicular pulp must be
uninflamed (can always go more apical)
if apical amputation in pulpotomy can’t control bleeding then:
use hemostatic agents and monitor
if vitality lost -> APEXIFICATION (pulpectomy)
pulpotomy is removal of ___ contents
pulp chamber only
APEXIFICATION goal
induce further root development in pulpless (dead) tooth by stimulating formation of hard substance at apex to allow obturation of root canal space
apex closes ___ yrs after eruption
2-3
apexification procedure
- isolate, access, remove all pulp
- calcium hydroxid-methylcellulose paste (ex. pulpdent), double cement seal
- recall 3 mo. (if no apexification, new paste)
- RCT
CaOH action
promotes formation of hard substance at root apex by creating ALKALINE environment
permanent tooth fractures, has fully formed root, LARGE exposure
what tx?
RCT
don’t need apexification because root is formed
permanent tooth fractures, has fully formed root, SMALL exposure, SHORT TIME (30 min. - 1 hr.)
what tx?
DIRECT PULP CAP with CaOH
what is a PULP CAP?
most common dressing for pulp cap is?
sedative and antiseptic dressing on exposed HEALTHY pulp; allows recovery and maintain normal fxn and vitality
Dycal = calcium hydroxide
2 situations where pulp cap has better success
- accidental exposure of pulp (NOT carious)
2. pulp of young child (NOT older ppl)
young pulps are more/less vascularized?
MORE, so more amenable to repair
pulp cap repair occurs when ____ forms at the exposure site
dentin bridge
pulp capping not recommended in primary teeth with CARIOUS exposures because
- high failure rate
- pulpotomy very successful
if pulp cap fails and tooth becomes symptomatic, might not be able to RCT because of
___ can also cause pulp space calcification and cause a ___ color
severe calcifications in root canal -> perf
trauma; yellow
INDIRECT PULP CAP is
procedure is
calcium hydroxide base on thin layer of questionable dentin remaining over pulp
- 3-4 mo. wait then reopen tooth
- remove remaining decay
if indirect pulp cap and SYMPTOMATIC (heat, percussion) and exposure
eventually RCT
in meantime, EUGENOL + IRM
DIRECT PULP CAP is
calcium hydroxide base directly on SMALL (< 1 mm) exposure
favorable factors for direct pulp cap
- uninflamed pink pulp
- no excess bleeding
- no symptoms of pulpitis
- small non-carious exposure (mechanical)
- clean cavity
direct pulp capping very successful in __ teeth
immature
direct pulp cap goal
stimulate DENTIN BRIDGE; preserve underlying pulp tissue in healthy condition
don’t do direct pulp cap on teeth with
hx of pain, percussion (+), periapical radiolucency
—> RCT
failure of direct pulp cap indicated by
symptoms of pulpitis or no vitality
adverse responses after direct pulp cap (3)
- necrosis
- calcification
- internal resorption
criteria before canal is obturated (4)
- good preparation to allow debridement and access to apex
- asymptomatic tooth; dry
- negative bacteria culture
- no nerve (shouldn’t respond to thermal test)
ACCESS PREP objectives (4)
- straight line access
- conserve tooth
- unroof pulp chamber
- remove pulp horns
what kind of access for maxillary primary incisors?
facial
common access istakes
1 Md molars - mesial under marginal ridge, lingual under lingual cusps
2. Md incisors - perf
3 Mx 1st PMs - perf
DEBRIDEMENT is
removal of foreign material and contaminated/devitalized tissue
most crucial aspect of RCT is
CHEMOMECHANICAL debridement
best/most reliable indicator of good debridement is
glassy, smooth walls
clean shavings on file or clean irrigant can measure good debridement, T/F?
F
inaccurate! need glassy, smooth walls
most common cause of root canal failure is
incomplete/inadequate disinfecting the root canal
2nd most common cause of root canal failure is
__%?
leakage from badly filled canal
40%
most effective way to reduce canal microorganisms is
complete canal debridement
objectives of root canal OBTURATION (3)
- fluid tight seal at apical foramen
- filling of root canal space
- favorable biologic environ. for tissue healing
if accessory/lateral canal not filled during obturation, the tx is:
eval every 3 mo.
after endo, takes ___ mo. before you see radiolucency get smaller on xray
6-12 mo.
after RCT, desirable changes are (3)
- regeneration of alveolar bone
- deposition of apical cementum
- PDL re-establishment
indications for solvent-softened custom GP cones (3)
- no apical stop
- abnormally big apical portion of canal
- irregular apical portion of canal
solvent softened custom cones not used if __ is achieved
TUGBACK
it doesn’t result in a better apical seal; should have a APICAL SEAT
master cone should reach how far
to apical position of prep or 1 mm short of foramen
why do you recapitulate?
clean apical segment of DENTIN filings not removed by irrigation
use your MAF after each increase in file size
regaining canal patency
- crown down (large to small)
- rotary > heated instruments
- light pressure with NiTi rotatry files
glass bead sterilizer sterilizeds files in __ sec at __ temp
15 sec 200 C (428 F)
techniques to remove GP
- rotary
- ultrasonic
- heat
- heat + instrument
- file
- chemical
reagent to dissolve GP
chloroform
others - xylol, halothane, benzene, carbon disulfide, essential oils, methyl chloroform, white rectified turpentine
irrigants (3)
- sodium hypochlorite (NaOCl)
- hydrogen peroxide (3%)
- urea peroxide (gly-oxide)
irrigant bactericidal action better than ___
intracanal meds
NaOCl
- most common
- conc. in 1%, 2.6%, 5.25% (not agreed which is best, all OK)
- good tissue solvent, antimicrobial, lubricant
- toxic to vital tissue
can disinfect GP points in __ solution for how long?
5.25% NaOCl, 1 min.
2 modes of action of hydrogen peroxide (H2O2)
- BUBBLING - foams debris from canal, an EFFERVESCENT effect
- liberation of OXYGEN - kills anaerobic bacteria
Urea peroxide (gly-oxide)
- avail. in anhydrous glycerol base (gly-oxide) to prevent decomposition
- better tolerated by tissue than NaOCl
- has BETTER solvent action and MORE germicidal than H2O2
good irrigant for canals with normal PA tissue and WIDE apices
urea peroxide (gly-oxide)
best use for gly-oxide is ___ canals
narrow, curved
utilize slippery effect
chelating agents (3)
- ethylene diamine tetra-acetic acid (EDTA)
- EDTAC (EDTA + Cetavlon)
- RC-Prep
chelating agents act on ___ tissues with little effect on ___ tissues
work on CALCIFIED tissues with little effect on PERIAPICAL tissue
action of chelating agents
act by substituting Na+ ions that combine with dentin to form soluble salts for Ca+ ions that are bound in a less soluble combination
canal edges become softer
helps prepare sclerotic canals after apex is reached with a fine instrument
EDTA
- removes mineralized portion of smear layer
- self-limiting, decalcifies up to 50 mm of root canal wall, stops as soon as chelator is used up
- 17% conc.
- active in canal 5 days
EDTAC (EDTA + Cetavlon)
- greater antimicrobial action than EDTA
- more inflammatory potential
- inactivated by NaOCl
RC Prep
- foamy solution
- combines EDTA and urea peroxide
- provides chelation and irrigation
- natural effervescense increased by irrigation with NaOCl
zinc oxide eugenol
- based root canal sealer
- fill discrepancies between core filling material and dentin walls (more important than core filling)
ZOE functions (3)
- lubricant for gutta percha
- forms bond btw gutta percha and dentin
- antibacterial
ZOE disadvantages
- staining
- slow setting time
- non-adhesion
- solubility
radiopacity in sealers are from
metallic salts
after filling canal with gutta percha, if there is a horizontal line of material (gp or sealer) extending mesially and distally from canal to PDL space -> indicates ___
root fracture
MTA
- best retro filling material
- seals APICAL portion of canal
___ must be placed when an apical seal may be faulty
reverse filling (MTA)
ex. calcified root canal
advantages of MTA (5)
disadvantages of MTA (2)
pros
- radiopaque
- hydrophilic
- biocompatible
- non-toxic
- induces hard tissue formation
cons
- hard to manipulate
- long-setting time
apicoectomy
oblique resection of most apical portion of root
flap tissue, buccal bone around root apex removed, area curetted
indications for apicoectomy
- reverse filling placed, need to gain access to area of pathosis
- poorly filled apical portion removed to level of canal obturated