Obturating Materials

Endodontic Instruments and
Materials
Dr. Sandra Shostad
Assistant Professor
Learning Objectives
1. Define a basic set of instruments
appropriate for Endodontic diagnosis, canal
preparation, obturation and emergency
treatment.
2. Describe the design (longitudinal, cross
sectional and tip configuration) of the common
instruments used for preparation of the canal.
Learning Objectives
3. Describe the basis for standardization
(sizing and taper) of files and reamers.
4. Describe the material used in
Endodontics to irrigate and disinfect, obturate
and seal the root canal system.
5. Understand the qualities of and “ideal”
obturating material.
Endodontic Diagnosis
1.
Radiograph (periapical and possibly
bitewing).
2. Percussion, Palpation, Periodontal
Probing.
Diagnostic Materials
Heat
Test
Apply
heated gutta-percha on paddle end of
a glick instrument to the mid-buccal (facial)
aspect of the tooth or crown
Cold
Test
Apply
ice or a liquid refrigerant (Endo
Ice)sprayed on a cotton pellet to the midbuccal (facial) aspect of the tooth or crown
Diagnostic Materials
Electric
Dry
Pulp Tester (EPT)
the tooth
Use mylar strips to separate contacts if
metal restorations are present in
interproximal.
Place conducting paste (tooth paste) on
probe tip
Have patient hold metal handle to
complete circuit
Electric Pulp Tester
Apply
probe with paste to one tooth on the
mid-buccal (facial) aspect.
Record numeric reading when patient
feels “shock-like” “pins & needles”
sensation.
Numbers are NOT diagnostic..This is an
all or none test to determine vitality. (0-80)
Cannot use on a tooth with a crown unless
there is enough exposed tooth structure
under margin!
Diagnostic Materials
Tooth
Slooth
Useful
in Dx of incomplete crown fractures
(cracks)
Materials Used for Isolation
Rubber Dam
Root Canal Treatment
1.
To clean and shape the root canal
system requires entry into the tooth
(access).
2. Instruments must then be
introduced into the canal(s) and
threaded to the end of the root (apex).
Root Canal Treatment
3.
The canal contents (pulpal tissue),
(dead or alive), must be removed, thus
cleaning the canal.
4. The canal must be tapered (shaped)
in order to facilitate removal of the
tissue and to allow for the filling
material to be introduced and
subsequently packed into the cleaned
canal, sealing all portals of exit.
Endodontic Treatment
5. Access Preparation
Round Burs: used to penetrate through
the coronal aspect of the tooth into the
pulp chamber
Tapered Diamonds: used to smooth the
access cavity walls
Accessing Through a Crown
Round Diamond
and carbide bur for
porcelain fused to
metal crown access
Hand Operated Instruments
Follow the original
canal
Not drift sideways
Be flexible
Cut on push
Disengage on pull
Have a high yield
strength
Be ductile
Be available in
graduated sizes
Have helical cutting
edges
Be corrosion
resistant
Hand Operated Instruments
Files
and Reamers
Begin
as a round wire which is modified to
form a tapered instrument with cutting
edges.
Most are made from stainless steel wire, a
few are made from carbon steel wire
which cuts more efficiently than stainless
steel but corrodes in irrigating solutions
and in the autoclave.
Nickel-titanium wire is used for greater
flexibility
Shape of Shaft
Rake and Clearance
Rake
the angle made by the edge of a cutting tool and a
plane perpendicular to the surface that is being
worked
Clearance
the distance separating moving objects or mechanical
parts
Rake and Clearance of Three
K-File Shaft Types
Hand Operated Instruments
Cutting
Mechanisms
Square
cross-sectional instruments have
more negative rake angles than do
triangular or rhomboidal instruments.
Hand Operated Instruments
Standardization:
ADA
specification No. 28 established
standards for instrument taper, tip
geometry, and size criteria for different
sizes of instruments (from size 8 to size
140) as well as acceptable tolerance of
manufacturing error. A revision of
specification No. 28 later added Size 6
files. Handles are color coded for easier
identification.
Hand Operated Instruments
Lengths
Files
and reamers are available in three
shaft lengths: 21, 25, and 31mm.
Hand Operated Instruments
Sizing
File
tip diameters increase in 0.05 mm
increments up to the size 60 file (0.60 mm
at the tip) and then by 0.10 mm
increments up to size 140.
Hand Operated Instruments
The
spiral cutting edge of the instrument
must be at least 16 mm long.
The diameter at the end of the file (tip) is
known as D1.
The diameter of the file at the top of the
cutting edge is known as D2.
The file diameter increases at a rate of
0.02 mm per running mm as you move
from the end of the instrument (D1) toward
the top of the cutting flutes (D2).
2
1
Hand Operated Instruments
Size
Example:
The
diameter of a size 10 file is 0.10
mm at D1, the diameter at D2 is (16
x.02)+ D1 (0.10) which equals 0.10 +
0.32 = 0.42mm in diameter at the top of
the cutting flutes (at D2).
Hand Operated Instruments
Files
and reamers are cutting tools
used to facilitate debridement and
shaping of the canal.
Rake is a term used to describe the
angle made by the edge of the cutting
tool and a plane perpendicular to the
surface that is being worked.
Clearance is a term used to describe
the distance separating moving objects
or mechanical parts.
Reaming vs.. Filing
Hand Operated Instruments
Hedstrom Files
-The greater the rake angle (more
positive) the greater the proportion of
cutting to scraping action, since the
concentration of stress at the cutting edge
is greater. This tends to fracture the
surface more easily. The Hedstrom file
with its positive rake angles is more
aggressive and tends to plane or cut the
surface, which can then be removed in
greater bulk.
Hand Operated Instruments
Barbed
Broaches
tapered stainless steel instruments, barbed
by scoring and prying tags of metal away
from the long axis of the wire. These
barbs entangle and remove canal
contents.
discard after use
Engine Driven Instruments
Gates-Glidden
Are
Drills
made from stainless steel
Are elliptically (flame-) shaped burs with a
latch attachment
Are used to open the orifice of the canal
and to achieve straight-line access by
removing the dentinal shelf and rapidly
flaring the coronal and middle third of the
canal
Engine Driven Instruments
GG’s
are available in 15 and 19mm lengths
They
are side-cutting drills
They
are designed to break high in the
shank region for easy removal of broken
instruments however if the bur head is
bound it will break off near the cutting
head and may not be able to be removed
Gates Gliddens
Engine Driven Instruments
Peeso
Reamers
Peeso
Reamers are similar to gatesglidden drills but have parallel cutting
sides rather than an elliptical shape.
They are tip cutting (unless they have a
safety tip).
They are aggressive cutting and can
rapidly over-enlarge the canal.
Gates Glidden vs.. Peeso Reamer
Equipment Needed
High speed hand
piece
Slow speed hand
piece with latch
attachment
Rubber dam set-up
(rubber dam,
punch, clamps,
radiolucent plastic
frame and rubber
dam forceps)
Mouth mirror
Standard explorer
Periodontal probe
Endodontic explorer
Endodontic spoon
excavator
Locking cotton pliers
Equipment Needed
Aspirating highvelocity suction tip
Burs and hand
operated files
Hand instruments
College pliers (nonlocking)
Endo file stand
Millimeter ruler
Equipment Needed Cont.
Hemostat (for
holding working
films)
5-6 ml Luer-Lok
syringe with 27guage needle
Pluggers and heat
carriers
Glick instrument
X-ray developing
clips
Spatula
Cup or other
receptacle for
sodium hypochlorite
irrigant
Irrigants Used in Endodontics
NaOCl
(Sodium Hypochlorite,
chlorinated soda)
Peridex (Chlorhexidine)
H2O2 (Sodium peroxide)
Anesthetic solution
Sterile saline
Irrigants
Purpose
of Irrigation:
Disinfection
Elimination
Organic
of debris
tissue remnants
Inorganic debris from filing
Lubrication
Irrigants
Sodium
Hypochlorite (Irrigant of Choice)
Characteristics
Dissolves
necrotic tissue through collagen
dissolution
“Puckers” vital tissue through osmotic
differences
Bactericidal and virucidal
Is a halogen
Cl is the best halogen disinfectant
Irrigants
Sodium
Mode
Hypochlorite
of Action
Oxidizes
free sulfhydral groups in the enzyme
system of the bacterial cell wall
-
Effects
-
-
Aids in the elimination of necrotic tissue by
dissolution
Aids in the extirpation of vital tissue through
osmotic dehydration of the vital tissue thus
collapsing the tissue and retracting the pulpal
projections from the dentinal tubules
Lubrication of canals
Irrigants used in Endodontics
Sodium
Hypochlorite
Dangers
Irrigation
(injection) into the periradicular
tissues
Excruciating pain
Periapical tissue bleeding
Extensive swelling
Irrigants
Dangers
of Sodium Hypochlorite, Cont.
Leakage
into the oral cavity
Tastes disgusting
vomiting
Destroys
clothing (patients, students,
faculty…)
Can irritate and damage skin, eyes…
Irrigants
Peridex
(chlorhexidine)
Characteristics
Antimicrobial
Absence
of toxicity
Does not possess tissue dissolving
properties like sodium hypochlorite
Irrigants
Sodium
Peroxide
Oxidizes
Especially
when used after sodium hypochlorite
H202 +NaOCl = H2o + NaCl + O2
Creating a bubbling effect due to the liberation
of free oxygen. Anaerobic bacteria do not like
oxygen!
Bleaches
the tooth
Irrigants
Other
irrigants
Anesthetic
Readily
Solution
available
Sterile
Sterile
Not
Saline
usually readily available
Chelating Materials
EDTA
(ethylenediamine-tetraacetate)
Available
in several different formularies
REDTA
(a liquid)
RC-Prep ( a gel-like preparation) containing
10% urea
Helps
remove inorganic debris and
chelates calcifications (removes smear
layer)
Intra-canal Medicaments
Calcium
Hydroxide
Normally
used as a slurry of calcium
hydroxide in a water base (commercial
preparations available or you can mix
powdered calcium hydroxide with sterile
anesthetic solution to create a slurry)
Intra-canal Medicaments
Calcium
Hydroxide
Actions
Antiseptic
Slow
Working
Ability to hydrolyze the lipid moiety of bacterial
lipopolysaccharides (inactivates biologic activity of
the LPS). Cell wall material remains after the
bacteria that caused the endodontic infection are
destroyed.
Intra-canal Medicaments
Calcium
Hydroxide
Uses
Intra-canal
antimicrobial medicament
Apexification/ apexogenisis
Matrix for repairs
Induce osteogenesis
Inhibit external resorption
Sealers
The
material used to fill the voids and
discrepancies between the core
material and the dentin walls, as well
as any space which the gutta-percha is
unable to fill because of it’s physical
limitations(accessory of lateral canals).
Sealers
The ideal sealer should:
Be tacky when mixed so as to provide good
adhesion, when set, between it and the canal wall
Provide a complete seal
Be radiopaque so that it can be visualized in the
radiograph
Have particles of powder which should be very
fine so that they can mix easily with the cement
liquid
Not shrink upon setting
Not stain tooth structure
Sealers
The
ideal sealer should cont.:
Be
bacteriostatic or at least not encourage
bacterial growth
Set slowly
Be insoluble in tissue fluids
Be tissue tolerant, (non-irritating to
periapical tissues)
Be soluble in a common solvent if it be
necessary to remove the root canal filling
Complement flow of gutta-percha
Sealers
Common
Zinc Oxide-Eugenol Sealer
Manufactured
Kerr,
and sold by:
(Romulus Mich.)
Pulp Canal Sealer
Richert’s Sealer
Tubli-seal
Sultan
Chemists, (Englewood, NJ)
Grossman’s Sealer
Properly Mixed Sealer
Sealers
Calcium
These
Hydroxide Sealers
sealers are promoted as having
therapeutic effects because of the calcium
hydroxide content. This has not been
shown to be the case. To be
therapeutically effective calcium hydroxide
must be dissociated into Ca++ and OH-,
however, the sealer must set and should
not dissolve or there would then be voids.
Sealers
Polymers
AH26
as Sealer
is an epoxy resin, originally
developed as a single filler material. It is
widely used as a sealer with gutta-percha.
It meets most of the standards for an ideal
sealer however is very toxic freshly
prepared. It releases a small amount of
formaldehyde, however after setting there
is little or no toxic effect.
AH26-Plus has been formulated which
does not contain formalin.
Obturating Materials
Gutta-Percha
The
most commonly used obturating
material
Is the dried juice of the Taban tree
(Isonandra percha)
Dissolves in chloroform, halothane and
xylol.
Obturating Materials
The
ideal obturating material should:
Be
easily introduced into the canal
Seal the canal laterally as well as apically
Not shrink after being inserted
Be impervious to moisture
Be bacteriostatic, or at least not
encourage bacterial growth
Not stain the tooth structure
Obturating Materials
The
ideal obturating material should:
Be
radiopaque
Not irritate periapical tissue
Be sterile, or easily and quickly sterilized
immediately before insertion
Be easily removed from the root canal if
necessary
Obturating Materials
Gutta-Percha
Characteristics
Poor
sealing material and therefore must be
used in conjunction with a sealer
Compactable, NOT compressible
Commercial
Gutta-Percha cones contain:
Gutta-percha
(19-22%)
Zinc oxide (59-75%)
Heavy Metal Salts (1-17%)
Wax or Resin (1-4%)
Obturating Materials
Gutta-Percha
Occurs
naturally as 1,4-polyisoprene
Is harder, more brittle and less elastic than
natural rubber.
GP is a linear crystalline polymer, which
melts at a set temperature, which causes
a random but distinct change in structure
Obturating Materials
Gutta-Percha
The
crystalline phase appears in two
forms:
Alpha
Phase (natural tree product)
Beta Phase (Processed form we use)
The
forms differ only in the molecular
repeat distance and single-bond.
Obturating Materials
Gutta-Percha
When
heated, GP undergoes phase
transitions.
Beta phase to alpha phase at around 115
degrees F. (46 degrees C.)
Change to amorphous phase at around
130-140 degrees F (54-60 degrees C.)
When cooled very slowly (1 degree F per
hour) it crystallizes to the alpha phase.
Normal cooling returns the gutta-percha to
the beta phase.
Obturating Materials
Standard
Points
Available
in standard sizes matching the
file sizes from size 10 through size 140.
Auxiliary
(Accessory) Points
Fine-fine, fine,fine-medium,medium,large
Obturating Materials
Silver
Points
Pure
silver molded in a conical shape has
been used since the 1930’s
Benefits
Stiff
material is easier to get into narrow canals
or canals with dilacerations
Stainless steel files have been cut off in canals
as an obturating material
Obturating Materials
Silver
Points
Problems
with silver points
Does not conform to canal shape
Contain other trace metals such as copper and nickel
When exposed to moisture corrosion occurs. The
silver corrosion products are highly toxic and may
themselves cause sever tissue injury.
Silver
points must also be used in conjunction
with sealer. If wedged into the canal they can
be very difficult or impossible to retrieve thus
forcing either surgery or extraction.
By wedging, they may split the root.
Obturating Materials
N2
Paste (Sargenti Paste)
Composition
Varies
Lead
oxide and organic mercury were formerly
major toxic components
Still contains large amounts of formaldehyde
Tissue
Reaction
Causes
coagulation necrosis within a short
time and cannot undergo repair for months
since it is impregnated with formaldehyde.
Obturating Materials
N2
Paste (Sargenti paste)
Problems
with N2 Paste
“Russian
Paste” is mixed with ZOP and sets
like a rock in the canal making retreatment
very difficult if not impossible
Leaching of formaldehyde into surrounding
tissues
Treating an apical pulp wound with strong
tissue coagulating material.
Obturating Materials
Other
Obturation Systems
Rigid
Systems
ThermaFil
(GP on a core similar to a plastic file)
Needs to be warmed or inserted
Injection
UltraFil
Techniques
heats GP to 158 degrees F (70
degrees C) and you inject this GP into the
prepared root canal
Obtura heats GP to 302 degrees F to 338
degrees F (150-170 degrees C)
Obturating Materials
Temporary Fillings
To seal and prevent bacteria and fluid products
from the oral cavity from contaminating the root
canal space
Most Common
IRM ( a reinforced zinc oxide cement)
Cavit
A ready mixed material composed of zinc oxide, calcium
sulfate, glycol and polyvinyl acetate, polyvinyl chloride
and triethanolamine.
It sets on contact with water (Hygroscopic)
Seals very well providing a better seal than IRM
Obturating Materials
Root
End Filling Materials
Silver
Amalgam
Zinc
in the amalgam may cause tissue
damage therefore use zinc free amalgam
IRM
Super
EBA Cement
Mineral Trioxide Aggregate (MTA)
Glass ionomer cements
Cavit
Repair Materials
MTA
(Mineral trioxide aggregate)
Predominantly
Portland cement (75%)
Calcium silicate compounds
Calcium compounds containing iron and
aluminum
Hydrated calcium sulfate
Repair Materials
Mineral
Trioxide Aggregate (MTA)
Indications
Root-end
filling material
Repair of root canals as an apical plug during
apexification
For repair of root perforations during root canal
therapy
As a consequence of internal resorption
As a pulp capping material