Contemporary Preparation and Obturation Techniques Flashcards
what is the objective of a RCT
The objective of RCT is to shape,
then clean, the root canal system on
order to remove micro-organisms,
their metabolic products and potential
substrate. Once this chemo-
mechanical preparation is complete
then to seal the root canal as well as
possible to create a favourable
environment for healing
summary of objective of a RCT?
Access the root canal system
Chemo-mechanical preparation of the
canals
Obturation of the canals
Restoration of the tooth
what are we looking for in chemo-technical prep?
Oversimplification but…….
Instrumentation phase
Irrigation phase
how do we instrument?
- Hand, rotary, reciprocating, swaggering,
adapting, conforming, self- adjusting…….
Each technique / file system has its place eg. some teeth prefer different instruments
Before use, essential to have good
knowledge of how they work, their pros and cons
Then can be applied them to an individual case, either as a system or as a hybrid technique
describe NiTiNOL?
Flexible
Resistant to fracture when placed into
curved root canal (up to a point…..)
resistant Torsional failure
Cyclic fatigue failure = ensure file moving up down
what are some NiTiNOL developments ?
Many contemporary files are now made
from heat treated ‘M-wire’
R-phase NiTi
Hugely increased resistance to CF
failure which allows for more inventive
movements and file designs
- makes them more flexible
what are some of the current file systems ?
Protaper Gold
Protaper Next
Wave One Gold
Reciproc
Twisted File Adaptive
Mtwo
BioRace
And the list goes on
describe Protaper gold
Rotary file, uses heat treated NiTi
Same geometry as Protaper Universal,
variable taper
Almost all cases can be treated using
this system
pros and cons of proper gold
Flexibility both good (curvature) and bad (sclerosed canals can causes bends)
Number of files in the system when
using manufacturer’s protocol
Increased resistance to CF failure
describe wave one gold ?
Reciprocating file
Same heat treated NiTi as PT Gold
Rotates 150 degrees CCW then 30
degrees CW
pros and cons of wave one gold
- Simple system
Good CF failure resistance
Minimal engagement with canal wall reduces torsional failure
Can create ledges if forced
Need to use orifice opening file in sclerosed canals
cost of files ?
Protaper Gold £9 (x4?)
Protaper Next £13 (x2?)
Wave One Gold £9 (x1?)
why is WL determination and canal prep important ?
Need to know where you want to finish
Anatomy of the apical region
WL anatomy
what are the 2 commonly used methods to figure out WL?
x-ray
apex locator
what is the zero reading ?
The “Zero” reading is the point where
the hard and soft tissues meet
Instrumenting to this point will invariably
lead to damage at the apical constriction
Depending on skill with instruments
consider working up to 1mm back of
this, whilst maintaining patency
what are some objectives with instrumentation phase ?
Preparing a shape that you can irrigate
and obturate
Conflicting evidence on what the optimal
shape is
Schilder’s principles still hold good
what is schilders design objective ?
Continuously tapering funnel from the
apex to the access cavity.
Cross-sectional diameter should be
narrower at every point apically.
The root canal preparation should flow
with the shape of the original canal.
The apical foramen should remain in its
original position.
The apical opening should be kept as
small as practical
what is the Instrumentation protocol using
Protaper Gold?
Estimate from pre-op radiograph
approximate WL, and also length to
curve
Place hand file to curve or as far as it
will go passively and open to size 15
Coronal flare, using XA to curve with a
brushing motion away from the furcation
Use hand file and EAL to get Zero reading
Prepare to Zero minus 0.5mm with S1/S2
Gauge apex to decide on MAF and recheck
with EAL
F1/F2 to length
what is the instrumentation protocol using
Wave One Gold?
Prepare glidepath by hand to curve
Coronal flare with Wave One primary file
to curve (can use GG or SX)
Establish WL with EAL, gildepath
creation by hand to length
Take WaveOne file to length using up
and down motion – 3 strokes and out
Gauge once at length – decide on
finishing size
why do we irrigate?
Many irrigants have been developed
and tried over the years
Best evidence shows that NaOCl 2%
gives the best outcomes
Can heat it, increase concentration but
no substitution for constant exchange
and refreshment within the canal
Irrigate during instrumentation phase,
but remember irrigant only goes 1mm
beyond needle tip
Most effective irrigation after preparation
phase completed
Keep syringe moving in the canal, don’t
wedge, side vented needle
Use some form of irrigant activation to
disrupt biofilm and encourage irrigant
into lateral and accessory canals
what is the gold standard for obtuaring ?
cold lateral
what is the aim of obturation
Aim of obturation is to create as good a
seal as possible, without extrusion of
material into the periapical tissues
Not possible to get a good obturation result unless principles of good preparation have been followed, no matter what
manufacturers claim
Obturation per se does not lead to healing
what problems do we face when obturating?
- complexity of RC system eg. multiple lateral canals
what are they different obturation techniques ?
Cold lateral = – still possible to get a ‘3D’
fill with correct technique and Very useful where apex is blown or canal anatomy does not lend itself to creation of retention / resistance form and simple and cheap
Warm lateral
Warm vertical
Carrier based
Paste
Cement
what are the pros of heated obturation techniques ?
– Demonstrate more 3D fill
Reduce leakage in leakage studies
Can be quicker but still time consuming to do properly
Risk of extrusion / loss of apical control
much higher
what is warm vertical compaction ?
Schilder or Continuous Wave
Master cone into canal, downpack with
System B, introducing heat as close to the
apex as possible
Backfill with Obtura
Seal canal orifice with barrier – IRM or GIC
- most utilised technique
- get more 3d fill
how do we choose what obturation technique to choose?
Consider what canal preparation and
shape you have got – obturate
accordingly
Cold lateral will work in vast majority of
cases and give a predictable outcome
If the obturation doesn’t work out,
consider altering the preparation
summary
There are lots of different ways to prepare and obturate root canals
Think what you are trying to achieve
mechanically and biologically
First principles of preparation and
obturation are the same however you do it
When you encounter a problem, always go back to the first principles
