Endodontics Flashcards
function and use of NaOCl (sodium Hypochlorite)
irrigant used during cleaning and shaping
tissue solvent with antimicrobial effect
typically used at 5.25%w
hydrogen peroxide function and use
used for canal irrigation
antimicrobial and effervescent effect (bubbling out debris)
3%
EDTA function and use
used to remove calcium, dimineralize and soften dentin, remove smear layer
chelating agent with antimicrobial effect
what is a chelating agent
agent with the ability to comine with metalls ion and thereby inactivate it
Chlorhexadine
intracanal cleansing agent
substantivity
why should chlorhexadine and NaOCl not be placed in the canal simultaneously
because it forms a precipitate that can block the canal
What is placed in a sealer to make it radioopaque
metallic salts
calcium hydroxide (CaOH) use and function
placed in the canal as antibacterial agent,
placed between appointments
increases pH in the canal
gutta percha contents
59-75% zinc oxide
19-22% gutta percha
1-17% metal sulfates
1-4% plasticizing wax and resin
Mineral Trioxide Aggregate (MTA) uses and function
cement like material used as root end filling, perforation repair, and pulp capping
Iodine Potassium Iodide uses and function
intracanal medicament/irrigant
antimicrobial action with little toxicity or irritation
Eugenol and eucalyptol uses and function
intracanal medicaments
lubricants function
decreases friction, decrease risk of file separation
How should reamers be rotated
no more that 1/2 turn at a time
D type files
rhomboid bland alternating large and small flutes
rubber dam function
- prevent irrigants from aspiration
- prevents aspiration of files and such
- prevent bacterial contamination
H type (Hedstrom)
spiral edges like a screw, cuts only on pulling stroke
K type
tightly spiraled, cuts on push, pull, rotation
NiTi (Nickle titanium)
elastic nickle titanium
What colors are the files (by size)
#10 purple #15 White #20 Yellow #25 Red #30 Blue #35 Green #40 Black
Objectives of Access Preparation
- Straight line access (prevent ledging, stripping, perforation)
- Preservation of tooth structure
- Unroofing pulp chamber to expose canal orifices
Maxillary central incisor access and canal
triangular (from lingual)
canal is large, conical and confluent with pulp chamber
Maxillary lateral incisor access and canal
triangular (from lingual)
smaller than central, concical
root tip is palatal or distal
Maxillary canine access and canal
canal is larger than max incisors, oval in shape
Wider BL than MD
rarely has divided canal at apex
Max 1st premolar access and canal
generally has 2 roots and 2 canals (palatal is larger) sometimes merge
Access is oval in shape (wider BL than MD)
Max 2nd premolar access and canal
Access is oval in shape (wider BL than MD)
60% have 1 canal (40% 2 canals)
typically 1 root
Maxillary Molars
Access in Triangular in shape (maintain oblique ridge)
3-4 canals (MB, P, DB, MB2)
P canal is straight, wide, tapered
DB is small and tapered
MB smallest, splits into 2 canals, difficult
Mandibular Incisors
Access circular in shape
single canal that may divide into B and L canals
Mandibular Canine
Access is oval (wider BL than MD)
common to have canal separate into 2
Mandibular premolars
Access is oval (Wider BL than MD)
cone shaped canal (70-80% have single canal)
Mandibular Molars
Access is blunted triangle (apex at D)
typically 3 canals (ML, MB, D) 4 canals = DL, DB
D canal is bisector of ML and MB
How to determine Working Length
- Select Stable reference point
- estimate with #10 or #15 hand file and X-Ray
- Use apex locator on #10 or #15 File and X-Ray
- correct X-ray discrepancy
- 1 mm short of radiographic apex
goals of instrumentation
- removal of pulpal tissue
- remove infected dentin (houses bacteria)
- Shape canal
What are the two ways canals are cleaned
biomechanical
Chemomechanical
What is the crown down technique
early flaring with rotary instruments
incremental removal of canals debris from orifice to apex
files used in a large to small sequence
Coronal portion cleaned and shaped before apical portion
What is the step back technizque
use smaller flexible files in the apical third
use sequentially larger files at incremental lengths
stay .5-1mm short of WL
apical portion prepared before coronal portion
gutta percha properties
flexible at room temp, plastic at 60 degrees C (140 F)
opaque (barium salts)
soluble in chloroform, ether, xylol
Lateral compaction technique
master apical cone selected at 1mm short of apex
walls coated with sealer
cone compacted against wall, another cone placed and compacted until canal is filled
warm vertical compaction
master cone selected, walls coated with sealer
cone pushed in and cut with hot instrument
hot instruement placed halfway down the canal melting apical gutta percha
condenser pushes GP apically
repeat until obturated
chloropercha technique
same technique as warm vertical compaction except chloroform is used to make GP plastic
Carrier based obturation
sealer is placed in the canal
warm coated GP is placed into the canal
continuous wave compaction
warm vertical compaction performed with a tip heated electrical plugger
problems with silver point obturation
post and core buildups became impossible
apical surgery is complicated
may cause inflammatory root resorption
should we remove asymptomatic, non problem causing silver points
nope
When to do surgical endodontics
obstructed canal wide apex inaccesible canal persistant apical periodontitis in well filled canal internal or external root resorption post and core in tooth
Root amputation or apioectomy
flap, bone removed, apex removed,
area curetted, retrograde filling
retrograde amalagam or MTA filling
apioectomy, followed by opening of apex and filling with MTA or amalgam
Used when retrograde filling isn’t likely to succeed
I&D and trephination
cleaning to relieve pressure and give the infection a path to drain
Hemisection
multirooted tooth cut vertically in half, defective half of the tooth is EXTd, RCT on the remaining half
(makes two teeth, EXT bad one)
Root amputation
removing infected root, leave entire crown
Intentional reimplantation
EXT tooth, perform RCT outside of mouth, Reimplant
poor prognosis
Preventing ledging
(straighter canals)
straight line access
good lubrication
flexible files
Ledging Treatment
relocate and renogotiate canal to WL (reverify) then filled and sealed
if ledge isnt removed
instrument to new WL, fill and seal (inform pt)
signs of perforation
sudden hemorrhage sudden pain radiograph apex locator not functioning right deviant file course severe post op pain
better prognosis of tooth with perforation if
its located above bone smaller than 1 mm occurs later in treatment easily accessable and treated good isolation well sealed after repair
Perforation treatment
repair with MTA extrusion and restoration crown lengthening and restoration root amputation or hemisection intentional reimplantation
prevention of instrument separation
use of the right instrument adequate lubrication and irrigation examine instruments for fatigue replace files often dont use larger files until small files don't bind
treating canals with separated files
remove instrument if accessable and loose
navagate around the instrument, leave it there
prepare and instument to WL above separated file (needs adequate seal)
prognosis of tooth with separated file better if…
minimal debris apical to file
separation occurs later in procedure
larger size file
Causes of Vertical Root fracture
excessive filling or condensation forces
wedge effect during post cementation
over preparation of the canal (thin dentin/cementum)
Symptoms of Vertical Root Fracture
serve perio pocketing
sinus tract development
pain with chewing
lateral root radiolucencies
Treatment of vertical root fracture
EXT of single rooted tooth
root amputation if possible (multi rooted tooth)
complicated vs uncomplicated fractures
complicated include the pulp, uncomplicated do not
Complicated fracture treatments
pulp capping (young teeth, pinpoint exposure, 1 hr or less) partial pulpotomy (young teeth, large exposure, less than 24 hours, vital pulp) pulpectomy (permanent teeth, large exposure, pain, long exposure)
Root fracture prognosis is good if
fracture is in apical third of root
low mobility
tooth is vital
root fracture treatment
splint tooth 4 weeks, take out of occlusion
PDL heals the fracture
vital tooth = granulation tissue, then calcified tissue
RCT if pulp necrosis occurs
Alveolar fracture diagnosis
mobility of multiple teeth
occlusal discrepency
radiograph or CT
alveolar fracture treatment
reposition bony segment splinted for 4 weeks
monitor teeth for vitality
concussion definition
injury to tooth causing tenderness to percussion
no displacement or mobility
good prognosis
subluxation
tender to percussion
slighlty mobile but not displaced
good prognosis
may need stabilization
extrusive luxation
teeth displaced incisally
typically mobile
tender to percussion
extrusive luxation treatment
cleanse area with saline reposition tooth suture gingiva splint for 2 weeks monitor vitality
lateral luxation
toot displaced laterally
usually fracture of facial cortical bone
sensitive to percussion
fracture is palpatable
lateral luxation treatment
cleanse area with saline reposition tooth suture gingiva splint for 2 weeks (4 or more in severe cases) monitor vitality
Intrusive luxation
displacement apically
tender to palpation and percussion
may intrude into sinus or nasal cavity
intrusive luxation treatment
incomplete root formation and less than 7mm of intrusion = allow re-eruption
complete root formation of greater than 7mm intrusion = surgical or orthodontic intervention
Avulsion
complete separation from the socket
may have alveolar fracture
avulsion antibiotic treatment
prescribe amoxicillin to 12 and under 7 days
prescribe doxycycline to 12 and older 7 days
if tooth touched soil recommend tetanus booster
post implantation instructions
soft diet for 2 weeks
no contact sports for 2 weeks
brush teeth with soft brush after each meal
rinse with .12% Chlorhexadine 2x per day for 2 weeks
avulsed tooth with closed apex already reimplanted
Rinse, radio, flexible splint
avulsed tooth with closed apex kept in medium <60 min:
clean, irrigate, radiograph, anesthetize, reimplant, radiograph, flexible splint
avulsed tooth with closed apex dry for > 60 min
remove necrotic tissue with gauze
soak in NaF 20 min
irrigate, radiograph, reimplant, radiograph, suture if needed, flexible splint (Endo prior if needed)
avulsed tooth with open apex already reimplanted
rinse, radiograph, flexible splint
avulsed tooth with open apex, in biological medium for < 60 min
clean, soak in doxycycline, irrigate, radiograph, anesthetize, reimplant, radiograph, flexible splint
avulsed tooth with open apex stored dry for > 60 min
remove necrotic tissue with gauze
irrigate, radiograph, RCT (apexification), reimplant, radiograph, flexible splint
External Resorption vs. inflammatory external resorption
external resorption from trauma, not bacterial in etiology
inflammatory ER = necrosis -> bacterial toxins leave -> ER
Replacement External resorption
ankylosis - PDL replaced with bone
internal resorption
inflammatory process, symmetrical RL in root canal, pulp may be vital or necrotic
Treat with prompt RCT
components of pulp
odontoblasts fibroblasts nerves blood vessels lymphatics
Pulpotomy
What
When
removal of the coronal portion of the tooth
in immature teeth, vital pulp
apexogensis
immature teeth, open apex, damaged coronal pulp but healthy radicular pulp.
after pulp capping or pulpotomy in immature teeth
hope that completion of the root happens so you have an apical stop for RCT
apexification
done on necrotic teeth with open apex
placement of CaOH or MTA in the apical third to foster completion of root formation
