L3 Obturation CLC-GP and Hydraulic Flashcards
what are the goals of obturation
eliminate all avenues of leakage from the oral cavity into the root canal system or out of the root canal system into the periodontal or oral tissues
you want to seal within the RC system:
any irritants that cannot be fully removed during canal cleaning and shaping and prevent their leakage out to the peri-radicular tissues or leakage of saliva or other contaminants into pulp system
RCT success depends upon thoroughness of:
removal of irritants and quality of seal of the canal system including coronal restoration
what are the qualities of gutta percha
- can be softened by heat and solvents
- if heated sufficiently will change phases
- following softening it shrinks
- GP by itself does not seal
- must consider sealers
what are the different isometric forms in which gutta percha exists
- alpha phase
- beta phase - CLC-GP
- amorphous melt
what temperature is GP at the beta phase
98.6 F or 37 C
what are the requirements for an ideal root filling cement
- should be easily introduced into the canal
- should seal the canal laterally and apically
- should not shrink after being inserted
- should be impervious to moisture
- should be bacteriostatic or at least not encourage bacterial growth
- should be radiopaque
- should not stain tooth structure
- should not irritate periapical tissue
- should be sterile, or quickly and easily sterilized before insertion
- should be easily removed from canal if necessary
what are the types of sealers
-Zn-O eugenol
- resin
- glass ionomer
- silicone
- calcium hydroxide
until bio-ceramic, bio-active sealers came into play:
no sealer was ideal and all sealers shrank upon setting and/or dissolved in body fluids over time
bio-ceramic sealers:
-do not shrink
- do not dissolve
- are bio active
BC sealer provides:
viability to the hydraulic technique
when is GP necessary with bio ceramic sealers
as a source of hydraulic sealer compression/flow and a route to retreatment or post
what is the standard of care for RC obturation
- GP positioned 1mm short of the canal exit
- totally filled with GP and sealer- no voids
- radiographic appearance of a dense filling
- avoidance of gross overextension into PA tissues
- minimal sealer beyond apical constriction
- no under fillings in the presence of a patent canal
when are we ready to obturate
- asymptomatic
- free of signs and symptoms of infection and inflammation
- tooth is cleaned and shaped to facilitate obturation
- tooth isolated to prevent contamination during obturation
- comfortable and master cone fitted and XR
- root canal is dry
- DST is healed
what are the acceptable obturation techniquea
- cold lateral compaction of GP
- hydraulic obt technique
- warm vertical compaction
which obturation techniqeus do we not use
carrier based techniques with thermafil
- chemoplasticized (chloropercha)
- custom cones/solvents
what is the secret to CLC-GP obturation success
compaction
what does compaction in obturation mean
fill must be dense and free of voids and have a thin sealer layer
describe cold lateral compaction
finger spreaders are used to compact the MC gutta percha in the canal to create space for more gutta percha accessory cones to accomplish a dense fill and thin film of sealer on the canal
- use .25 GP cone (red)
what are the steps to lateral compaction
- master cone is fitted
- a finger spreader or plugger is inserted ideally to 6-2mm of the prepared length
- the spreader is rotated and removed and an accessory cone is placed in the space created
- repeat
what is used with hydraulic obturation
BC sealer and .04 GP cones
what is the size of the gutta percha cone the same as
the size of MAF
how do you test the fit of the gutta percha master cone
gently insert in WET canal until resistance is felt near apex
- mark on the GP cone exactly to your reference point
what happens in the radiograph if the GP master cone is too small
- distorts/crinkles near apex
- will have spaces
what does it look like if the master cone is too big
will not seat at WL
what is the last chance to correct a problem easily without re treatment
the master cone radiograph
where should the. master cone stop when inserted
at WL
if the MC is not tight at WL:
get a bigger master cone
describe the hydraulic technique
- use a double coat technique on the master cone
- place GP gently in the root canal
- may dart additional GP cones in irregular canals
- sear off as per CLC-GP technique
- beware of possible sealer getting into mandibular canal on mandibular premolars and molars
describe the cementation of the master cone
coat with sealer and place slowly and carefully to WL in canal then the master cone is removed from the root canal, coated again with sealer and gently repositioned to working length without any pumping motion
what do you do with a type II canal
pick the easiest canal to fill to WL the second canal will merge into the first at some point short of WL
what do you do with a wide canal
darting in additional 25/02 cones as necessary without the need of spreading
how do you control the apical constriction
- do not take any instrument larger than your patency file beyond WL
- take care to never go beyond WL with any shaping instruments
what should you do with an open apex
use CLC-GP instead of single cone
what restoration do premolars and molars require and why
crowns to prevent VRF
what restoration do anterior teeth require
may only need a composite restoration to restore RCT access with minimal loss of tooth structure
what are the take home messages
- use GP with a bioceramic sealer
- obturate when the canal is dry and patient has remained asymptomatic
- lateral compaction needs blue finger spreaders
- hydraulic obturation technique uses an .04 GP cone and BC sealer
- sear GP below CEJ, clean the pulp chamber and seal the canal with GI
what is gutta percha
trans-polyisoprene - an isomer of latex
what GP is used in lateral compaction of GP
.02 taper GP
- sizes #20-#50
what is the composition of gutta percha
- gutta percha: 18-22% (plasticity)
- zinc oxide: 59-76% (filler and mildly antimicrobial)
- waxes/resins/coloring agents: 1-4%
- metal sulfates: 1.5-1.8% (radiopacity)
silver points are:
beneath the standard of care
why are silver points unacceptable
- round peg in irregular hole
- corrodes when sealer washes out (silver oxide)
- may stain both tooth and gingiva
why is paraformaldehyde containing pastes beneath the standard of care
- N-2 sargenti paste
- potential for great damage
- proven carcinogen
why is any conventional paste only obturation doomed
paste will shrink and dissolve
film pressure is required for dense fill but excessive force of compaction can cause:
iatrogenic fracture of root
what is the ideal GP sealer
- compatibility
- inertness
- tissue tolerance
- inexpensive
- malleable
- relatively easy to work
- useful in many techniques
- dimensional stability
- resistance to dissolving
what are bad characteristics of sealer
- notoriously poor seal
- expands and contracts with solvent and temperature
