lecture 3: obturation Flashcards
goals of obturation
- eliminate all avenues of leakage from the oral cavity into the RC system or out of the RC system into the periodontal or oral tissues
- 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 contaminates into pulp system
rct success depends on thoroughness of ____ and _____ the canal system including ____
- removal of irritants
- quality of seal of
- coronal restoration
obturation materials
gutta percha
qualities of gutta percha for obturation
- can be softened by heat and solvents
- if heated sufficiently, will change phases
- following softening shrinks
- GP by itself does not seat
- must consider sealers
GP can exist in which isomeric forms
- alpha phase (42 to 44)
- beta phase** (below 42)
- amorphous melt (56 to 64)
6 standards of case for RC obturation:
- avoidance of gross overextension into the periapical tissues (GP and Sealer)
- minimal sealer beyond apical constriction
- no under-fillings in the presence of a patent canal
- GP positioned 1mm short of the canal exit
- totally filled with gutta percha and sealer want no voids
- radiograph shows dense filling
what are acceptable obturation techniques
- cold lateral compaction of GP
- hydraulic obt technique
- warm vertical compaction
what is compaction
the secret to CLC-GP obturation success.
Fill must be dense and free of voids and have a THIN sealer layer to be effective.
when are we ready to obturate
- when free of all signs and symptoms of infection/inflammation
- asymptomatic
- 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
if the pt is still in pain or the original symptoms have not abated, obturation of the RC ____ resolve the pts symptoms
will not
GP master cone fitment
- select proper size 0.02 ISO gp cone
- use gutta gage to confirm gp size is correct
- gently insert in WET canal until resistance is felt near apex (NaOCl simulates the lubricity of sealer)
how do we select which size gp cone to use
match the MAF
different sizes of GP cones
- all are 0.02 taper gp cones
- #.15/.02 to #.50/.02 up to #100+ as used for CLC-GP
make sure to “mark” on your GP cone what
exactly to your reference point
in the apical region how does the master cone fit
- it only needs a slight frictional fit
- this permits deep spreader penetration between the gp and the canal wall
if the master cone is too small
- cone is too small in diameter and distorts “crickles” near apex.
how does a properly fitted cone fit
- has an immediate fit at WL with NO spaces and no crinkling
CLC-GP: Master Cone Fitment and WL
- MC should NOT extend past working length
- it should STOP at WL
- MC must NOT be able to be pushed beyond WL (tap on it to make sure)
if the MC is NOT tight at WL what should you do
or if it pushes longer
GET A BIGGER MASTER CONE
if the MC is too large
-MC is too large coronally or canal taper is insufficient and will not seat at WL