Restoration of endodontically treated teeth / dental implant courses

RESTORATION OFRESTORATION OF
ENDODONTICALLYENDODONTICALLY
TREATED TEETHTREATED TEETH
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.co
m

INTRODUCTIONINTRODUCTION
• Present day clinicians are well aware
that “The naturally retained root is the
ultimate dental implant.”
• It is well known that with proper
endodontic treatment and adequate
restoration, pulpless teeth can serve
indefinitely as an integral part of the
dental apparatus, provided the
supporting structures are not
compromised.www.indiandentalacademy.co
m

• Hence in the last 2 decades much research
has been directed towards properly designing
post-endodontic restorations.
• Very critical to long-term endodontic success
is the placement of a well designed post
endodontic restoration which provides
adequate ferrule, promotes periodontal
health, harmonious occlusion and esthetics
while preventing microleakage.
• From the time of Pierre Fauchard till date a
wide range of materials, techniques and
designs have been described to restore
endodontically treated teeth.www.indiandentalacademy.co
m

• However, there is no clear consensus
regarding an ideal system, this is
because each tooth presents with a
unique requirement.
• A thorough understanding of the
proper use of posts and cores will
enable clinicians of today to provide an
optimum restoration that uniquely
balances between maximizing retention
of the tooth while minimizing the risk
of failure. www.indiandentalacademy.co
m

DEFINITIONSDEFINITIONS
• Dowel : a post, usually made of metal
that is fitted into a prepared root canal
of a natural tooth. When combined with
an artificial crown or core, it provides
retention and resistance for the
restoration
• Core : the center or base of a structure
m

Post-core crown: a restoration in
which the crown and cast post is one
unit
Ferrule: a metal band or ring used to
fit the root or crown of a tooth
m

HISTORY AND EVOLUTIONHISTORY AND EVOLUTION
• Restoration of endodontically treated
tooth by a post to retain a crown
dates back more than 250 years.
• In 1728, Pierre Fauchard a French
dentist used “Tenons” which were
metal posts (Gold or silver) screwed
into the roots of teeth to retain
bridges.
m

• In the mid 1800’s, wood replaced
metal as the post material, and the
“Pivot Crown”, a wooden post fitted
to an artificial crown and to the root
canal became popular.
• Harris in 1839, proposed that gold
and platinum were superior to brass,
silver and copper which tended to
corrode.
m

• As early as 1849, when there was
little emphasis on cleaning and
shaping endodontic procedures,
Tomes proposed the principles of post
dimension.
• 1849 –Dr.F.H.Clark – developed a
“spring loaded dowel” a retentive
device consisting of a metal tube in
the canal and a split metal dowel
which was inserted into it.
m

• G.V. Black developed porcelain fused
to metal crown held in by a screw
inserted into a canal filled with gold
foil.
• In the late 19th century 1888, the
“Richmond Crown”, a single piece
post-retained crown with a porcelain
facing was engineered to function as
a bridge retainer.
m

• During the 1930s, the custom cast
post and core was developed to
replace the one piece post crowns.
• In 1960s prefabricated posts were
introduced.
• 1990 Duret et al described a non
metallic material for the fabrication of
posts based on carbon fibres
reinforcement principle.
m

This was followed by the 2nd
generation of aesthetic posts which
are more translucent and tooth
colored and comprising of purely
glass fibre and quartz fibre.
Thus the evolution of the metal free
posts.
Carbon fiber -> Combination -> All esthetic posts
m

Are endodonticallyAre endodontically
treated teeth differenttreated teeth different
m

• Architectural changes
• Altered physical characteristics
• Altered esthetic characteristics
• Loss of Neuro-sensory feedback
m

Endodontically Treated Teeth
have special “NEEDS” that
“EXCEEDS” the requirements of
the teeth with viable pulp
m

Aims of post endodontic
restoration:
• Restoration of tooth function and
aesthetics.
• Resist functional load.
• Maintenance of periodontal health.
m

Endodontically treated teeth are
weakened due to:
• Caries.
• Previous restoration.
• Trauma.
• Endodontic access opening, canal
instrumentation and irrigation.
• Decreased moisture content of the
tooth.
m

EVALUATION OFEVALUATION OF
ENDODONTICALLY TREATEDENDODONTICALLY TREATED
TEETHTEETH
• ENDODONTIC EVALUATION
• PERIODONTAL EVALUATION
• RESTORATIVE EVALUATION
• ESTHETIC EVALUATION
m

ENDODONTIC EVALUATION
What should be evaluated before
restoring an endodontically treated
tooth?
m

• Good apical seal as revealed by
radiographs.
• No tenderness on percussion
• No apical tenderness.
• No active inflammation.
m

Evaluate for
Good apical as revealed by radiographs
No tenderness on percussion
No apical tenderness
No active inflammation
No
Yes
Continue further treatment
Retreat
Monitor
Continue Post-endodontic
treatment
No improvement
Apicoectomy
No improvement
Extraction
Improvement
Stop further treatment
ENDODONTIC EVALUATION
m

PERIODONTAL EVALUATION
• Periodontal health is critical to the long term
success of teeth that have been
endodontically treated and restored.
• Periodontal condition must be assessed
before endodontic treatment, and the effect
of planned restoration on the attachment
apparatus must be considered.
• Any structural defects of teeth should be
considered that jeopardize coronal
restoration.
• Extensive caries, tooth fracture, previous
restoration, perforation and external
resorption can destroy tooth structure at the
level of the periodontal attachment.www.indiandentalacademy.co
m

• An attempt to place restorative margins on
solid tooth structure beyond these defects
further invades the biologic attachment zone.
• Clinical results are bad when biologic width is
violated.
• A mutilated tooth in which restorative
treatment would compromise the junctional
epithelium or connective tissue attachment
levels should be considered for periodontal
crown-lengthening surgery or orthodontic
extrusion, in addition to endodontic and
restorative procedures.
• All weak teeth due to caries or fracture that
cannot be restored should be extracted.
m

Biological Width Biological Width Encroachment
m

Caries
Fracture
Previous restorations
Periodontal evaluation
Evaluate for
Not restorable Restorable
Extraction Continue Post-
endodontic treatment
RESTORATIVE EVALUATION
m

ESTHETIC EVALUATION
• Potential esthetic complication should
be investigated before initiation of
endodontic therapy.
• Thin gingiva may transmit a shadow of
dark root or through the tissue.
• Metal or dark carbon fiber post and
amalgam placed in the canal can result
in unacceptable gingival discolouration
from the underlying root.
m

• The translucency of All-ceramic crowns must
be considered in the selection of dowel and
build-up materials.
• Tooth coloured carbon fiber glass-reinforced
composite resin, or zirconia posts can be
used in esthetic areas. Similarly, tooth
coloured, rather than opaque, composite
core material should be selected for
esthetics.
• An intact endodontically treated tooth
requires critical control of endodontic
materials in the coronal third of the canal
and pulp chamber in order to maintain its
colour and translucency.
m

• Gutta percha discolouration can be
visible in the coronal aspect of an
endodontically treated tooth and
should be limited to an apical level in
the root.
• Endodontic and restorative materials
in these esthetically critical cases
must be selected to provide the best
health service with the minimum of
esthetic compromise.
m

TREATMENT PLANNING OFTREATMENT PLANNING OF
ENDODONTICALLY TREATEDENDODONTICALLY TREATED
TEETHTEETH
m

All the changes that accompany root canal
therapy influence the selection of
restorative procedures for endodontically
treated teeth.
Important considerations include the
following :
• The amount of remaining tooth structure.
• The anatomic position of the tooth.
• The functional load on the tooth.
• The esthetic requirements for the tooth.
m

The amount of remaining tooth structure
• Tooth structure loss can range from minimal
access preparation in intact teeth to extensive
damage that endangers the longevity of the tooth
itself.
• The amount of tooth structure damage is one of
the most important aspects in restoration of the
endodontically treated tooth.
• Teeth with more than half of the tooth structure
intact are inherently stronger than damaged teeth
and can be restored conservatively with coronal
restoration and without posts inside the roots.
• Conversely, extensive tooth structure loss from
caries, fracture and previous restorations
significantly weakens the remaining tooth, making
dowels, cores and crowns necessary.
m

The anatomic position of the tooth
Anterior teeth : Intact, non-vital, anterior teeth
that have not lost tooth structure beyond
the endodontic access are at minimum risk
for fracture. Generally they do not require a
crown, core or dowel. Restorative
treatment is limited to sealing of access
cavity.
• A non-vital anterior tooth that has lost
significant tooth structure requires a crown.
The crown can be supported and retained
by dowel and core.
m

Posterior teeth : In case with adequate tooth
structure, onlays or crowns may be placed.
Only when the remaining tooth structure is
less, then dowels and cores are done.
Functional load of the tooth
The horizontal and torquing forces endured
by abutments for fixed or removable partial
dentures dictate more extensive protective
and retentive features in the restoration;
similarly teeth that exhibit extensive wear
from bruxism, heavy occlusion, or heavy
lateral function require full complement of
dowel, core and crown.
m

Esthetic requirements of the tooth
• Anterior teeth, premolars and often
maxillary 1st molar inhabit the esthetic
zone of the mouth.
• Teeth in the esthetic zone require careful
selection of restorative materials, careful
handling of the tissues and timely
endodontic intervention to prevent
darkening of the root as the tooth loses
vitality.
• Current restorative materials for these
teeth include tooth-coloured dowels, tooth
coloured composite resin or ceramic cores,
tooth coloured cements and various
porcelain or ceramic crown materials.www.indiandentalacademy.co
m

Basic components used in the
restoration of an ET tooth
The final configuration of the restored tooth
includes four parts:
• Residual tooth structure and periodontal
attachment apparatus.
• Post material, located within the tooth.
• Core material, located in the coronal area
of the tooth.
• Definitive coronal restoration.
m

Post
The post is defined as a metallic or non metallic
material inserted into the root canal to aid in
retention of a core component.
Function
•Retention
•Protection
m

INDICATIONS FOR POST
• To retain the restoration: When insufficient tooth
structure remains to hold a restoration (extensive
caries, coronal fracture, etc) placing a dowel that
extends occlusally provides this coronal retention.
• To protect remaining tooth structure: Since the
crowns of pulpless teeth are often partially or
completely destroyed or removed, occlusal forces
cannot be delivered to the remaining tooth and
periodontium in a natural way. So posts are used to
direct occlusal and lateral forces more apically.
• Marginal integrity: by providing sufficient rigidity
under load, this re-distribution helps maintain
marginal integrity of the final restoration.
• Core and crown retention: To retain a
reconstituted clinical crown or “core” over which a
permanent restoration can be cemented.
m

CONTRAINDICATIONS FOR POST
• Abnormal root anatomy.
• Extensive caries including root caries.
• Perforations.
• External resorptions.
• Short roots.
• Dilacerated roots.
• Blunderbuss canal.
• Young patients with coronal fracture, with
incomplete root formation.
• Patients with poor oral hygiene.
m

Classification
Ingle and Bakland
I. Custom-cast Posts
II. Prefabricated Posts
a) Tapered, smooth-sided
b) Parallel-sided
c) Tapered, self-threading screws
d) Parallel-sided, threaded
e) Parallel-sided, tapered apical end
m

Shillinburg and Kessler
I. Custom-cast Posts
II. Prefabricated posts
a) Tapered, smooth-sided posts
b) Tapered, serrated posts
c) Tapered, threaded posts
d) Parallel, smooth-sided posts
e) Parallel, serrated posts
f) Parallel, threaded posts
m

Robbins
I. Metallic Posts
A. Custom-cast Posts
B. Prefabricated Posts
1. Passive Tapered Posts
2. Passive Parallel Posts
3. Active Posts
II. Non-metallic Posts
A. Carbon Fiber Posts
B. Tooth Coloured Posts
1. Fiber reinforced posts.
2. Ceramic and zirconia posts
m

Materials Used
Metals
(a) Custom-cast posts
(i) Gold alloys
(ii) Chrome-cobalt alloys
(iii) Nickel-chromium alloys
(b) Prefabricated posts
(i) Stainless Steel
(ii) Titanium
(iii) Brass
Non-metals
(a) Carbon-fiber
(b) Fiber-reinforced
(i) Glass fiber
(ii) Quartz fiber
(iii) Woven Polyethylene fiber
(c) Ceramic and zirconiawww.indiandentalacademy.co
m

Ideal requirements of post
• Simple and safe.
• Biocompatible.
• Should support the core and crown.
• Should provide resistance for stresses.
• Maximum protection of root.
• Adequate retention within the root.
• Pleasing esthetics, when indicated.
• High radiographic visibility.
• Easily removable.
• Less expensive.
m

1) Adequate apical seal
2) Minimal canal
enlargement
3) Adequate Post Length
4) Positive horizontal stop
5) Vertical wall to prevent
rotation
6) Extension of final
restoration margin on to
sound tooth structure
m

Custom-cast metal posts
Indications:
• When multiple posts and cores are being placed in the
same arch.
• When posts and cores are being placed in small teeth.
• When the angle of the core must be changed in relation to
the post
• In excessively flared and elliptical canals….
• Cast post and cores…..easy to retrieve….
m

Drawbacks
•Requirement of temporary restoration…
•Tapered design…wedging forces.
m

Pre-fabricated posts
Different post designs
a) Tapered, Smooth-Sided Posts
The oldest and most widely used design.
Eg : Kerr Endopost, Mooser post and all custom-cast posts.
Post Retention:
The tapered, smooth-sided, cemented post is the least
retentive of all post designs.
Used in teeth not subjected to high functional or
parafunctional loads and where other designs are
contraindicated. www.indiandentalacademy.co
m

• Stress from Installation:
Because of their taper, these posts are
self-venting and easily cemented.
Hydrostatic pressures do not develop
during cementation because a taper does
not act as a piston.
• Stress from Mastication:
Tapered-smooth posts are wedges and, as
such, exert a wedging pressure upon roots
during function.
m

b) Tapered Posts with Self-Threading Screws
Eg : Dentatus
Post Retention: More retentive……gains its retention by
spreading into the dentin as it self-threads.
Stress from Installation: Sets up fracture lines as it “cuts”
and spreads its way into the dentin.
Stress from Mastication. The wedge configuration of the
screw design is accentuated under load when occlusal
forces are added to the installation forces described above.
Self-threading tapered screws possess the worst
installation and occlusal stress-producing characteristics of
all existing designs. www.indiandentalacademy.co
m

c) Parallel-sided Posts
Examples are Whaledent posts which has introduced
three post designs: the original Para-Post, Para-Post
Plus, and the Unity System. All are passive, parallel,
vented posts made of either stainless steel or
titanium.
The Para-Post System
Post Retention: The parallel-sided, serrated, vented
post provides substantially greater retention than the
smooth tapered design. Consequently, these posts
can be effectively employed in situations where higher
applied forces are expected.www.indiandentalacademy.co
m

• Stress from Installation: The Para-Post
has a vertical groove cut along the length
of its serrations, allowing axial venting.
This design allows cement to escape….
• Stress from Mastication: Provide the
most equitable distribution of masticatory
forces of all available post designs.
Avoids the wedging effect of tapered
posts. The transfer of occlusal forces of the
tooth occurs via the cement layer, which
serves to buffer the forces. Together, these
two factors result in a uniform distribution
of stresses in the supporting tooth.
m

d) Parallel-sided Posts with Tapered Apical Ends
Provide the greater retention of parallel posts and also
better conform to the tapered apical portion of the canal.
Come in 2 variations. Degussa & Unitek BCH System..
Post Retention: Lower retention potential than regular
parallel posts of comparable length and diameter.
Stress from Installation: Produce little or no installation
stress.
Stress from Mastication: Produce a definite wedging
effect in the area of the apical taper….cause root fracture
than parallel-sided posts of comparable length and
diameter.
m

e) Self-Threading Parallel-Threaded Posts
Eg: Radix Anchor System.
They have low frequency sharp threads, and are
vented to reduce hydraulic cementation stress.
Like the other active-retentive posts, Radix Anchor
posts gain their primary retention by self-cutting
counter threads in the dentin. They have sharp low-
frequency helical blades that extend only partly
down the shaft. It is vertically vented. The Radix
post is designed to fit snugly in a channel prepared
for it in the root. www.indiandentalacademy.co
m

• Post Retention: Because of the limited
number of threads, the Radix Anchor has
less retention than other actively retained
posts.
• Stress from Installation: A fully seated
Radix Anchor induces severe stress due to
surface irregularities and the non-
perpendicular alignment of the post and
coronal dentin.
• Stress from Mastication: Since there are
so few threads on the Radix Anchor, the
localized stress concentrations are raised
under load because of the lowered surface
contact.
m

EVOLUTION OF
AESTHETIC POSTS
CARBON FIBRE
CARBON+QUARTZ
QUARTZ/GLASS
LIGHT TRANSMITTING
m

CLASSIFICATION OF FIBRE BASED POSTSCLASSIFICATION OF FIBRE BASED POSTS
BASED ON COMPOSITION
CARBON SILICA POLYETHYLENE ZIRCONIA
GLASS QUARTZ
m

CLINICAL
APPLICATION
CUSTOM MADE
INTRARADICULAR
REHABILITATION PREFABRICATED
DIRECT
FABRICATION
m

CARBON FIBRECARBON FIBRE
• Introduced in 1990 by
Duret and associates in
France.
• They consist of
continuous,
unidirectional, pyrolytic
carbon / graphite fibres
reinforced in an epoxy
resin matrix with 64%
carbon.
• Parallel sided, smooth
post, wider coronally
and tapers towards the
apex. www.indiandentalacademy.co
m

ADVANTAGES
• Better strength
• High flexibility
• Easy retrievability
• Better redistribution of stresses
• High fatigue resistance
m

DISADVANTAGES:
• Aesthetics– the black colour of post
has a negative effect on the final
aesthetic result of all ceramic crown
• Poor adhesion to composite resins as
the heat processed carbon fibre posts
have little free resin available for
chemical reaction causing failure of
post / cement interfere.
• Lack of radioopacity
m

GLASS FIBER POSTSGLASS FIBER POSTS
Glass fibers have a
lower elastic modulus
than carbon / graphite
fibers.
These posts can be
made of different types
of glasses.
i. Electrical glass
ii.High strength glass
m

QUARTZ FIBRE POSTSQUARTZ FIBRE POSTS
Additionally glass
fiber post can also
be made of quartz
fibers. Quartz is
pure silica in
crystallized form. It
is an inert material
with a low co-
efficient of thermal
expansion.
m

Advantages
• Flex with the tooth structure
• Easy to retrieve, if retreatment is
required
• Aesthetic compatibility
• Greater fracture resistance
• Useful in polymerization by
transmitting light through the post.
• Physical properties of these posts is
similar to carbon fibre posts.
m

WOVEN-FIBRE COMPOSITE MATERIALS/WOVEN-FIBRE COMPOSITE MATERIALS/
POLYETHYLENE FIBRE MATERIALSPOLYETHYLENE FIBRE MATERIALS
• Use of cold gas
plasma treated,
polyethylene woven
fibres embedded in
conventional resin
composite
• Consists of woven
fibre ribbons
• Direct fabrication
technique
m

CERAMIC BASED POSTS
Ceramic posts are aesthetic as well as
biocompatible. They also exhibit improved
strength and durability for the use with all-
ceramic restorations.
Advantages:
• Dentin like shade.
• It does not reflect intensively through thin
gingival tissues, and it provides an essential
depth of translucency in the cervical root
areas.
Disadvantage:
• High cost
m

THE CORE
The core is defined as a restorative
material placed in the coronal area of a
tooth to replace the missing coronal
structure. The core is anchored to the tooth
by extending into the coronal aspect of the
canal, or through the endodontic post.
m

Ideal properties of the core material
• High compressive and tensile strength.
• High modulus of elasticity (rigidity).
• High fracture toughness.
• Dimensional stability.
• Ease of manipulation.
• Short setting time.
• The ability to bond to both tooth and post.
• Biocompatibility.
• Inert (no corrosion).
• Natural tooth color, when indicated.
• Low plastic deformation.
• Low cost. www.indiandentalacademy.co
m

Core materials
• Cast core
• Amalgam
• Composite
• Glass ionomer cement
• Resin modified glass ionomer cement.
m

Cast core
This has been the traditional
means for restoring
endodontically treated teeth.
The cast core is an integral
extension of the dowel and
the cast core and hence
does not depend on
mechanical means for
retention to dowel. This
construction avoids
dislodgement of the core
and crown from the dowel.
Usually noble metals can be
used to construct cast cores.
m

Advantages
• They can be cast directly onto a prefabricated post,
providing a restoration with good strength
characteristics.
• Conventional high-noble metal-content alloys can be
used.
• An indirect procedure can be used, making
restoration of posterior teeth easier.
Disadvantages
• Higher ratio of root fracture than preformed dowels.
• Cost is high.
• More appointments.
• Laboratory phase is technique sensitive.
• Casting a pattern with a large core and a small
diameter dowel can result in porosity in the gold at
the dowel and core interface.
m

Dental amalgam is a traditional core build-up material with a
long history of clinical success
Amalgam core
m

Advantages
• Not especially technique sensitive.
• Strong in bulk.
• Sealed by corrosion products.
• Can be bonded to the tooth by means of cements.
• High compressive strength, high tensile strength,
high modulus of elasticity.
• Withstands functional stresses thus protecting the
residual tooth structure, cement and crown margins.
• It is easily manipulated and has rapid setting time.
• Simple to use and economical.
• Coronal radicular stabilization increases the retention
of amalgam cores.
m

Disadvantages
• It needs 24 hours to set before final tooth
preparation.
• Weak in thin sections.
• Mercury content may be of concern to some
patients and dentists.
• Potential electrolytic action between core and
metal crown.
• Not intrinsically adhesive.
• Corrosion and subsequent discolouration of
gingiva or remaining dentin.
m

Composite resin core
LUXOCORE
CORE-FLO
CORECH 2
2 PASTE CORE
BUILD UP
MATERIAL
m

Advantages
• Strong compressive strength.
• Can be used in a thinner section than
amalgam.
• Fast setting (either light or chemically cured).
• Does not always need a matrix during
placement
• Avoids mercury controversy.
• Ease of manipulation.
m

Disadvantages
• Highly technique sensitive.
• Relies on multi-stage dentin bonding
requiring effective isolation.
• Dentin bond can be ruptured by
polymerization contraction.
• Minor dimensional changes caused by the co-
efficient of thermal expansion (3 times
higher than tooth) and water absorption –
not usually clinically significant.
• Can be difficult to distinguish between tooth
and core during preparation.
m

Glass-Ionomer core
Advantages
Useful for small buildups or to
fill undercuts in prepared teeth.
Fluoride release -
anticariogenic quality but does
not guarantee freedom from
secondary tooth decay.
Intrically adhesive.
Similar coefficient of thermal
expansion to tooth.
m

Disadvantages
• Considerably weaker than amalgam and composite.
• Low strength and fracture toughness results in
brittleness, which contraindicates the use of G.I.C.
build ups in thin, anterior teeth or to replace
unsupported cusps.
• Low retention to preformed metal dowels.
• Tendency to crack worsened by early
instrumentation.
• Silver containing materials offer little improvement
in physical properties.
• Some materials are radiolucent.
• It is soluble, sensitive to moisture.
• Adhesive failure can result from contamination of
the tooth surface with cutting debris, saliva, blood or
protein.
• Not strong enough for a core for an abutment tooth.
m

Resin modified Glass-Ionomer coreResin modified Glass-Ionomer core
Advantages
• Stronger than
G.I.C’s.
• Either intrinsically
adhesive or with
simplified bonding
system. Bonding
higher than
traditional G.I.C.
• Fluoride release.
• Exhibits minimal
microleakage.
m

Disadvantages
• Most are weaker than amalgam and
composite.
• Some materials can inhibit surface
setting of addition silicone
impressions.
• Not reliable like amalgam and
composite as an interim restoration.
m

PRINCIPLES OF TOOTHPRINCIPLES OF TOOTH
PREPARATIONPREPARATION
• CONSERVATION OF TOOTH STRUCTURE
• RETENTION FORM
• RESISTANCE FORM
• PROTECTIVE QUALITIES
• ESTHETIC QUALITIES
m

CONSERVATION OF TOOTH
STRUCTURE
• Preparation of canal
• Preparation of coronal tissue
m

Preparation of canal
• When creating post space, great care must
be used to remove only minimal tooth
structure from canal.
• Excessive enlargement can perforate or
weaken the root, which then may split
during cementation of post or subsequent
function.
• Thickness of remaining dentin is the prime
variable in fracture resistance of the root.
• Larger diameter post caused more fractures
them smaller posts, and also induced more
stresses.
m

Preparation of coronal tissue
Endodontically treated teeth have often
lost much coronal tooth structure as a
result of caries, previously placed
restoration, preparation of endodontic
access cavity or trauma.
If cast post and core is to be used,
further reduction is needed to
accommodate a complete crown and to
remove undercuts from the chamber
and internal walls.
This may leave very little coronal dentin.
m

Preservation of coronal tooth
structure is necessary to reduce
stress concentration at gingival
margins which is also necessary for
creating a ferrule.
Crown lengthening does provide a
ferrule but it results in an
unfavourable crown to root ratio thus
increasing the leverage on the root
during function.
m

RETENTION FORM
Affected by
– Post length
– Diameter
– Surface texture
– Luting agent
– Luting method
– Preparation of canal space and tooth
– Dowel design
– Dowel composition
m

Post length
• As post length increases, retention
increases, however the relationship is
not linear, an extremely long post may
damage the seal of the root canal fill or
risk root perforation if the apical third is
curved or tapered.
• Ideally the post should be as long as
possible without jeopardizing the apical
seal or the strength or integrity of the
remaining root structure.
m

Various concepts of post length
• Preservation of 3-5mm of gutta percha at apex.
• Equal to inciso-cervical or occluso-cervical length of
crown.
• The post should be longer than the crown.
• The post should be 1 ⅓ the length of the crown.
• The post should be certain fraction of the length of
the root such as one half, two third, or four fifth.
• The post should end halfway between the crestal
bone and root apex.
• The post should be as long as possible without
disturbing apical seal.
m

Post diameter
Increasing the diameter of the post
does not provide a significant
increase in the retention of the post,
however it can increase the stiffness
of the post at the expense of the
remaining dentin and the fracture
resistance of the root.
m

Philosophies of post diameter
The Conservationist The Proportionist The Preservationist
m

The Conservationist
• Minimal instrumentation of canal after
removal of gutta percha.
• Instrumentation limited to removal of
undercuts in canal.
• Endodontically treated teeth with
smaller diameter dowels resist fracture
better.
• Enlarging the canal till clean dentinal
shavings extruded from the orifice.
m

The Proportionist
• The diameter of dowel should be 1/3rd the
diameter of root.
• The dowel space should not exceed 1/3rd
the width of root at its narrowest
dimension.
• They suggested that one third relationship
preserved sufficient tooth structure to
resist root fracture.
m

a. Post space prepared
b. Wide post causing fracture
c. Ideal post width
The Preservationist
This philosophy of dowel diameter depends on a minimal
thickness of dentin surrounding the entire dowel to prevent
tooth fracture.
Atleast 1mm of sound dentin be maintained around the entire
circumference.
m

Post surface texture :
A serrated or roughened post is
more retentive than a smooth one,
and controlled grooving of the post
and root canal considerably
increases the retention of tapered
post.
m

Luting agents :
Retention provided by luting cements:
Zinc phosphate cement < Polycarboxylate
cement < G.I.C < Adhesive resin cement
Adhesive resin cements improve the
performance of post-and-core restorations.
• Precaution : Resin cements are affected by
eugenol-containing root canal sealers, which
should be removed by irrigation with ethanol
or etching with 37% phosphoric acid if the
adhesive is to be effective.
• The choice of luting agent may become
more important if the post has a poor fit
within the canal.www.indiandentalacademy.co
m

A. Cement placed
on post
B. Cement Placed
in the canal
C. Cement Placed
both on the post
and in the canal
Luting method
A B C
m

Preparation of canal space and
tooth :
It is a 3 stage operation :
• Removal of endodontic filling
material to the appropriate depth.
• Enlargement of the canal.
• Preparation of the coronal tooth
structure.
m

Removal of the Endodontic Filling
Material
• It is recommended that the root canal
system should first be completely
obturated and then space made for a
post. This will ensure that the lateral
canals are sealed.
• Silver point………?
m

The two commonly used methods for
gutta-percha removal are:
• With a heated endodontic plugger.
• With a rotary instrument
m

Enlargement of the CanalEnlargement of the Canal
This is accomplished with
instruments, Peeso reamers
or a low speed drill. The
purpose is to remove
undercuts and prepare the
canal to receive an
appropriately sized post
without excessively enlarging
the canal.
Before starting canal
preparation, remove any
existing restorations, caries,
bases and thin or
unsupported walls of tooth
structure, preserving as much
tooth structure as possible.www.indiandentalacademy.co
m

For Pre-fabricated Posts
• Set the stopper on the instrument to the predetermined length. Enlarge
the canal one or two sizes with a drill, endodontic file or reamer that
matches the configuration of the post.
• Enlarging the canal in 0.2 mm increments diminishes the possibility of the
instrument straying from the canal.
• Care should be taken not to remove more dentin at the apical extent of
the post space.
• In case of a threaded post, a tap (to make threads in the dentin) follows
the appropriate drill, unless self-threading screws are being used.
• To provide anti-rotational resistance, a pin may be used. Drill one or two
0.6 mm pin holes to a depth of 2mm, in the area of the greatest bulk
between the canal and the periphery of the tooth (usually on lingual side).
m

For Custom-made Posts
• Often very little preparation will be
needed for a custom-made post.
• However, undercuts within the canal
should be removed and some
additional spacing is usually
necessary.
m

Preparation of Coronal Tooth Structure
• After the post space has been prepared, the
coronal tooth structure is reduced for the
extracoronal restoration.
• Ignore any missing tooth structure and prepare
the remaining tooth as though it was undamaged.
• The facial surface (in anteriors) should be
adequately reduced for good esthetics.
• Remove all undercuts that will prevent removal of
pattern.
• Preserve as much tooth structure as possible.
• Prepare the finish line at least 2mm gingival to the
core. This establishes the ferrule.
• Complete the preparations by eliminating sharp
angles and establishing a smooth finish line.
m

Ferrule effectFerrule effect
Without ferrule With ferrule
It originates from combining the Latin for Iron (ferrum) and Bracelets (viriola).
m

• The walls and margins of the crown or cast telescopic
coping encasing the gingival 2mm of the axial walls of
the preparation form the ferrule.
• A properly executed ferrule significantly reduces the
incidence of fracture in the non-vital tooth by
reinforcing the root at its external surface and also by
dissipating force that concentrates at the narrowest
circumference of tooth.
• Stress in the radicular dentin during function is
concentrated to the circumference of the tooth,
whereas the stress level is lowest within the root
canal.
• The ferrule also resists lateral forces from posts and
leverage from crown in function, and it increases the
retention and resistance of the restoration.
• To be successful, the ferrule must encircle a vertical
wall of round tooth structure above the margin and
must not terminate on restorative material.
m

Requirements
•A maximum of 2mm of dentin axial wall height.
•Parallel axial walls.
•Metal must totally encircle the tooth.
•It must be on sound tooth structure.
•It must not invade the attachment apparatus.
m

Advantage of ferrule
– Reduces the incidence of fracture in the non-vital
tooth by reinforcing the tooth at its external
surface and dissipating force that concentrates at
the narrowest circumference of the tooth.
– Fracture resistance is increased with increasing
ferrule length.
– It resists the lateral forces from dowels and
leverage from crown in function and it increases
the retention and resistance of the restoration.
– It helps to bind the remaining tooth structure.
m

Insufficient crown length – What to do?
a. Insufficient crown height
b. No ferrule effect
c. Ferrule effect achieved after
crown lengthing
m

Surgical crown lengthening
Gingivectomy Procedure
Insufficient Crown Height Gingivectomy Done
Crown Height Increased
and Crown Given
m

Surgical Crown Lengthening
Insufficient Crown Height Sulcular Flap Elevated and
Apically Repositioned
Crown Height Increased
(Front View)
Crown Height
Increased
(Occlusal View)
m

ORTHODONTIC TOOTH EXTRUSION
3 weeks after rapid eruption.
Adequate root structure exposed
Sulcular fiberotomy done
every 4 days
Inadequate Crown Height
Eyelet Post Cemented and
Tooth Pulled Out
m

Pre-eruption Radiograph Post- eruption Radiograph
m

Dowel design :
– Parallel sided, serrated and long dowels have best
retention and distribute functional loads to root
more passively than tapered dowels.
– Parallel posts resist tensile, shear and torquing
forces better than tapered post and distribute
stress more evenly along their length during
function, providing greater protection against
dentin failure.
– Tapered serrated posts create a wedging effect,
with the greatest stress created at the coronal
shoulder, whereas tapered smooth sided post
generate greatest stress at the apex of the
preparation.
– When dislodged, cement adheres to parallel sided
serrated posts whereas it occurs at the post
cement interface in tapered post.
m

– Parallel post in tapered roots risk perforation
and weakening of dentin wall, hence parallel
post with tapered ends have been developed
although they are less retentive.
– Serrated surfaces of metal dowels increase
retention over smooth metal surfaces by
providing mechanical undercuts for cement.
– Carbon fiber and fiber reinforced composite resin
dowels are luted with resin cements which
provide chemical bonding to the root, hence
they need not be as long as traditional dowels. A
1:1 ratio between dowel length and replacement
crown is sufficient.
m

Post configuration Example
Most retentive
↓
Least retentive
Parallel threaded
Tapering threaded
Parallel serrated
Parallel smooth-
sided
Tapering smooth-
sided
Kurer Crown
Saver
Dentatus,
Obturation screw
Parapost
Stainless steel wire
Gold casting
Retentiveness of dowels with regard to dowel configuration
m

Dowel composition
Metal dowels are more retentive than carbon fiber dowels
Stainless steel dowels are more retentive with composite resin cores
than carbon fiber dowels
Post
length
Luting
cement
Ferrule
Effect
Retention Triad
m

RESISTANCE FORMRESISTANCE FORM
• Stress distribution
• Rotational resistance
m

Stress distribution
– The main function of post and core is to
improve resistance to laterally directed
forces by distributing them over as
large an area as possible.
– Excessive internal preparation of root
weakens it, and the possibility of failure
increases.
– The post design should distribute
stresses as evenly as possible.
m

Influence of post design on stress distribution
The greatest stress concentration is found
at the shoulder, particularly interproximally,
and at the apex. Dentin should be conserved
in these areas if possible.
Stresses are reduced as post length
increases.
Parallel-sided posts may distribute stress
more evenly than tapered posts, which may
have a wedging effect. However, parallel
posts generate high stresses at the apex.
Sharp angles should be avoided because
they produce high stresses during loading.www.indiandentalacademy.co
m

High stress can be generated during
insertion, particularly with smooth, parallel
sided posts that have no vent for cement
escape.
Threaded post can produce high stress
concentration during insertion and loading,
but they have been shown to distribute
stress evenly if posts are backed off a half
turn.
The cement layer results in a more even
stress distribution to the root with less
stress concentration.
m

Rotational resistanceRotational resistance
• It is important that a post with a
circular cross section does not
rotate during function. This
should not present a problem in
areas where sufficient coronal
tooth structure remains, because
rotation is usually prevented by
a vertical coronal wall. In areas
where coronal dentin has been
completely lost, a small groove
placed in the canal can serve as
an anti-rotational element.
• The groove is normally located
where the root is bulkiest,
usually on the lingual aspect.
Antirotational groove
m

Slots or Cloverleafs
It is made at the
orifice with a thin,
pointed, tapered
diamond stone or
No.557 carbide bur. Slots or Cloverleafs
m

Post
Design
Antirotation
feature
Remaining tooth
structure
Resistance Triad
m

PROTECTIVE QUALITIESPROTECTIVE QUALITIES
• Dowel shape
• Dowel diameter
• Dowel length
• Dowel Composition
• Dowel design for damaged roots
m

Dowel shape
– Parallel metal dowels distribute
functional loads to root more passively
than tapered dowels.
– Tapered dowels act as a wedge to exert
lateral forces on the tooth that can
result in tooth fracture and also they are
closely adapted to the internal shape of
root canal so leading to root fracture.
m

Dowel diameter
Larger diameter dowels give no
improvement in the dowel to root retention
but will significantly increase the risk of root
fracture.
– Parallel metal dowels are available in
narrower diameters than non-metallic
dowels.
– Non-metallic dowels are narrower in apical
portion and bulky at coronal portion thus
requiring more dentin removal.
m

Dowel length
Metal dowels should be long enough
to extend below the crest of alveolar
bone root to reduce concentration of
force in an area of root that is not
embedded in alveolar bone. The
greatest protection against root
fracture comes from coronal
restoration.
m

Dowel Composition
Now-a-days dowels are used with properties
that are similar to those of dentin.
– Occlusal forces are transferred through the core
to the dowel and ultimately disbursed along the
length of the root as the dowels, cements and
restorative materials behave in comparison to
dentin.
– Metal and zirconia dowels are stiffer than dentin.
– Fiber glass – reinforced composite matrix, woven
fiber, ribbon-reinforced composite, carbon fiber or
carbon core dowels approximate the stiffness (i.e.
modulus of elasticity of dentin).
– Stainless steel is stiffer than titanium alloy, which
is stiffer than pure titanium dowels.
m

Dowel design for damaged roots
– Composite resin technology can be used to unify
the radicular dentin and dowel and core structure
in damaged roots.
– In thin, flared canals retention of dowels can be
achieved with custom dowel and cores that reflect
the internal canal shape.
– Composite resin, coupled with central metal dowel
can be valuable in reinforcing internal radicular
walls of roots thinned by caries and dentin
defects.
– The resultant dentin and composite dowel complex
is 50%, stronger than roots restored
conventionally.
– Composite resin and dentin bonding system can
also be reinforced with polyethylene fiber system
to create an entirely custom dowel and integrated
core.
m

ESTHETIC QUALITIES OFESTHETIC QUALITIES OF
DOWELDOWEL
– Current restorative procedures allow fabrication
of highly esthetic, ceramic, composite
restoration that contains no metal substructure.
– These restorations have remarkable depth of
life-like colour vitality, with no unnatural
opacity, shadows, gray discolourations, or
artificial brightness from underlying metal or
masking agents.
– Carbon core, zirconia or fiber glass – reinforced
composite resin dowel systems are all esthetic.
– When these dowels are given they are not
radiographically visible, only a faint outline from
the cement delineates their presence.
m

– Zirconium dowels are radiopaque, but are
stiffer than dentin. They are considered an
esthetic equivalent to preformed metal
dowels.
– Carbon fiber and metal dowels are not
esthetic and should not be used for
esthetically critical restoration. They are
appropriate for teeth to be restored with
gold or porcelain fused to metal
restoration.
m

Post Fabrication
Prefabricated posts
•These have to be selected to match the dimensions of the
canal.
•They must be seated till full depth.
•Any discrepancy between the coronal part of post and
canal wall can be filled with core material during the build up
of core.
•Shorten the length of the post:…
m

PREFABRICATED POST AND CORE TECHNIQUE
Post Space Preparation Post Space Prepared
Pre Fabricated Post
Tried-in
Post adjusted Luting cement
placed in canal
m

Post cemented
Core built
Completed Core Crown Cementedwww.indiandentalacademy.co
m

Fabrication of CustomFabrication of Custom
made postmade post
• Direct technique
• Indirect technique
• Direct technique recommended for
single canals
• Indirect technique more
appropriate for multiple canals
m

Direct techniqueDirect technique
Materials
• Inlay wax
• Thermoplastic resin
• Autopolymerising resin
• light polymerised resin
m

Using auto polymerising resinUsing auto polymerising resin
Lubricate canal
Select a loose fitting plastic dowel.
Should extend to full depth of
prepared canal
Notch it
Add resin on post using bead-brush
Technique Or Mix some rein  roll in
cylinder shape introduced in canal  Push with monomer
moistened dowel.
1. add resin only to canal orifice first
m

Do not allow resin to harden fully
Loosen and reseat it several times
Once polymerised remove it
2. Form apical part of post by adding additional resin
 reseat and removing
Care not to lock it in canal
m

add additional resin for core
formation
Slightly overbuild the core
and let it polymerize
Shape the core with
carbide finishing burs.
m

2.Rosenstiel et al (JPD 1997;77;209)2.Rosenstiel et al (JPD 1997;77;209)
Using thermoplastic resin materialUsing thermoplastic resin material
Palstic rod selected
(Merritt EZ post system)
Should extend to full depth
of prepared canal
Be loose
Should be 1.5-2mm above
the occlusal surfacewww.indiandentalacademy.co
m

• Lubricate canal
• Heat thermoplastic
material
• Apply on apical
aspect of rod
m

Insert the rod
Wait for 5-10 secs reseat
Inspect for completeness
m

Core build up using
autopolymerising resin
Trimmed to ideal tooth
preparation form
Final preparation.
m

3. William H. Silverstein3. William H. Silverstein
(JPD1964;14;374(JPD1964;14;374))
• First prepare tooth
for crown
• prepare temporary
acrylic resin crown
• Prepare tooth for
post and core
casting www.indiandentalacademy.co
m

Fabricate direct wax pattern with aid ofFabricate direct wax pattern with aid of
temporary resin crown.temporary resin crown.
m

Orthodontic wire bend in
J shape
Verify fit loosely fit, extend
to full depth
If too tight impression will
tear away
Indirect procedureIndirect procedure
m

• Coat wire with adhesive
• Lubricate canal (die lubricant)
• Fill canal with elastomeric
impression material
(using lentulo spiral)
• Seat wire to full length
• Syringe some impression
around teeth, insert impression
tray
m

Remove impression
Pour cast
m

• In lab, select a
plastic post
(toothpick)
• Using impression
as guide make sure
it extend to full
depth
m

Lubricate stone cast
Add inlay wax in
increments on post
Pattern fabricated
m

Add wax core
and shape it
m

(J Prosthet Dent 2002;88:555-7.)
m

Vinyl polysiloxane
material seated over
prepared teeth on stone
cast.
teeth prepared for
custom-cast posts
m

Plastic posts fitted and coated
with autopolymerizing
acrylic resin.
Posts and cores immediately
after removal of index material
m

Refined posts and cores
m

Direct technique for posteriorDirect technique for posterior
Shillingburg et al (JPD 1970)Shillingburg et al (JPD 1970)
Plastic tooth pick-loose
First mix of acrylic resin
fills the canal and
completely covers
the occlusal surface
m

Second mix of resin for completion
of core preparation
Finished pattern
m

2.2. Single piece core with auxiliary post
Indirect approach better as
access is better
Fit prefabricated post into
prepared canal
Roughen one post, others
smooth and lubricate
All posts should extend beyond
eventual preparation.www.indiandentalacademy.co
m

Build core with autopolymerising resin
Shape it
Grip smooth posts with forceps and
remove Remove pattern
invest
m

Indirect pattern for multirooted teethIndirect pattern for multirooted teeth
(split core)(split core)
Wax the custom made post
Build up part of core
around first post
m

Remove any undercuts
adjacent to other post holes
Cast it
Wax additional sections
Cast them
m

Interlocking sections can be made using dove tails
Complicated
Limited benefit as final
build up is held together
by fixed cast restoration.
m

TEMPORIZATION AFTER POSTTEMPORIZATION AFTER POST
PREPARATIONPREPARATION
Post spaced prepared
Cotton wool placed till the apical part of the
preparation over the remaining gutta percha to
prevent temporary cement uniting with the root
filling cement
Pre fabricated post cemented with temporary
cement
Core built up with acrylic and
temporary crown given
m

• After endodontic treatment, if a cast post
and core is planned, a provisional crown
with attached temporary post can be
fabricated for the teeth with limited
supragingival structure.
• A provisional restoration is also needed
while the post and core is being fabricated
to prevent drift of adjacent and opposing
teeth.
• The final post, core and crown should be
fabricated as soon as possible, because
microleakage can contaminate the post
space and endodontic fill.
m

Investing and castingInvesting and casting
• The post-core pattern is sprued on the incisal
or occlusal end.
• 1.0 to 2.0 cc of extra water is added to the
investment and a liner is omitted to increase
the casting shrinkage. This results in a
slightly smaller post that does not bind in the
canal, and it also provides space for the
cement.
• When resin is used, the pattern should
remain for 30 minutes longer in the burnout
oven to ensure complete elimination of the
resin www.indiandentalacademy.co
m

POST REMOVALPOST REMOVAL
• When there is failure of post-endodontic
treatment, there arises a need to remove
to post to facilitate non-surgical
retreatment.
• In other instances, the endodontic
treatment may be successful but to
improve design mechanics, or aesthetics
of a new restoration removal of the
existing post may be necessary.
m

Factors influencing post removal
• Operator experience.
• Anatomy of tooth-such as :
Variations.
External concavities.
Root wall thickness.
Length, shape and curvature of root canal.
• Types of post used.
Parallel/Tapered.
Actively engaged/Non-actively engaged.
Metallic/Non-metallic.
• Type of luting cements used.
Zinc phosphate – easy to remove.
Composite resin cement/Glass Ionomer cement –
difficult
• Inter-occlusal space.
• Existing restoration.
• Coronal aspect of post – Supracrestal / Subcrestal.
m

Methods of removal of
posts
•Mechanical methods.
•Ultrasonic methods.
m

Hemostat Forceps and
Stiglitz Forcepswww.indiandentalacademy.co
m

Masseran Kit
Mini Masseran Kit
Trepan Bur Masseran Extractor
m

Trepan Bur adjusted over Post Canal after post removal
Trepan Bur placed over post Technique of removal of Post
m

Advantages:
• Simple.
• Less heat generated.
• No danger of pushing fragments
further into the root.
• Excessive forces are eliminated with
little chance of perforation or splitting
the root.
m

Post removal using Post Puller
m

PRS Kit composed
of 5 variously sized
trephines and
corresponding
taps, a transmetal
bur, rubber
bumpers, a torque
bar and extracting
pliers.
m

Fiber Post Removal Kit
Eggler Post Remover
m

Ultrasonic methods
m

REVIEW OF LITERATUREREVIEW OF LITERATURE
m

Harry Rosen (1961), described
ferrule as an extracoronal ‘brace’
which is a subgingival collar or
apron of fold which extends as far
as possible beyond the gingival seat
of the core and completely
surrounds the perimeter of the
cervical part of the tooth. It is the
extension of the restored crown
which, by its hugging action,
prevents vertical shattering of the
root.
m

Weine FS and co-workers
(1973), recommended that to
increase surface of post and increase
retention, use of long post rather
than wider post, which also
preserves remaining dentin and
width of post should be 1/3rd width
of the root.
m

Standlee JP (1978), in his study using 3
post systems : a) Unitek, b) Whaledent
Parapost, c) Kurer using different cements
and different lengths and diameter, found
out that Kurer (threaded tapped) was more
retentive than Whaledent Parapost (parallel
cemented with vents) which was more
retentive then Unitek (tapered). He
reported that the retention also increased
with the embedment depth. Cement and
dowel diameter had very little to do with
retention but Zinc phosphate was much
better than Carboxylate and Epoxy cement
in performance.
m

Gordon D. Mattison and Philip D.
Delivanis (1984), evaluated the apical seal
during post space preparation using
chloroform, heated pluggers and Gates-
Glidden Drills (No.6) and found out there is
maximum leakage in chemical method
(chloroform) as evaporation results in
shrinkage of filling material towards its
center, leaving a discrepancy at Gutta-
percha – dentinal wall interface. Thermal
(Heated plugger) and mechanical (Gates-
Glidden) showed less leakage than chemical
method due to vertical pressure on gutta
percha by heated pluggers and frictional heat
leading to expansion of gutta percha by
Gates-Glidden drills.
m

Allan S. Deutsch and Barry Lee
Musikant (1985), checked for root
fracture during insertion of prefabricated
posts and found out that, a) Tapered,
threaded posts increased the incidence of
fracture by 20 times, b) When a 1.5mm
diameter post was used, root fracture
increased six fold for each millimeter that
diameter of the root at the CEJ decreased,
c) Smaller teeth with less bulk were
shortened from the post hole to the border
of the tooth, which further complicated
post insertion.
m

Dilts WE et al., (1985), compared
the bond strength of luting media
with various core materials and found
out that zinc phosphate was best with
amalgam cores; polycarboxylate
cement provides strongest bond with
base metal alloy cores and resin
adhesive cement provides the
strongest resistance to shear with
cores of composite or gold alloy.
m

Gary R. Goldstein, Stephen Hudis
and Dale Weintraub (1986),
compared 4 techniques for
cementation of cast post restoration
that were using lentulo spiral,
endodontic explorer, paper point and
direct application of cement on post
and found out there were minimum
voids in using lentulo spiral but
retention of post was the same in all
techniques.
m

Joseph P. Cooney, Angelo A. Caputo
and Kenneth Trabert (1986), did a
study comparing Para-post, Tapered-end-
para post and BCH post and found out that
parallel sided (Para-Post) was more
retentive than parallel posts with tapered
ends (Tapered-end-para-post and BCH
Post) and retention increased with greater
depth but not with greater diameter. They
also found that tapered-end post produced
wedging stresses near apex which was
more with smaller diameter posts. More
uniform stress distribution was observed
with parallel sided posts and larger
diameter posts at greater depths produced
the best distribution of applied loads.
m

Reel DC et al., (1989), assessed in
their study influence of 3 cementation
techniques: a) Placing cement on
post, b) Placing cement in canal, c)
Placing cement on post and in canal
on retention of anatomic posts and
found out that the retentive force was
higher when cement was placed in
canal.
m

Arturo Martinez-Insua et al.,
(1998), did a comparison of the
fracture resistances of pulpless teeth
restored with cast post and core and
carbon-fiber post with composite core
and found that fracture threshold
values were higher in former but
showed fracture of tooth; carbon fibre
post showed failure at posts/core
interface before the fracture of the
tooth occurred.
m

Richard S. Schwartz, David
Murchison and William Walker
(1998), studied the effects of
Eugenol and non-eugenol endodontic
sealer on post retention using resin
cement and zinc phosphates cement
and found that when eugenol sealers
were used, it affected retention of
posts cemented with resin cements
where as eugenol sealer had no effect
on posts cemented with zinc
phosphate cement.
m

SummarySummary
m

• The past few decades have witnessed
an accelerated rate of change in the
field of dentistry with advancements
in materials, techniques and concepts
that have been well researched and
scientifically accepted.
• While root canal therapy saves
roots, sound post- endodontic
restoration saves crowns.
• Combined, these procedures have
been able to successfully salvage
more teeth to form and function in
recent times.www.indiandentalacademy.co
m

• There is not one post, core, or final
restoration that can be used in all clinical
situations.
• When we understand the basic concepts of
how to retain the various restorative
components and how to protect remaining
tooth structure, our ability to answer the
numerous questions that arise during the
restorative process will be facilitated.
• This could result in final restorations that
are based on sound design principles.
m

References
• Rosenstiel, Land and Fujimoto.
Contemporary Fixed Prosthodontics.
2nd Ed.; Mosby, St. Louis, 1995.
• Shillinburg. Fundamentals of Fixed
Prosthodontics. 3rd Ed.;
Quintessence, Chicago, 1997.
• Tylman’s Theory and Practice of fixed
Prosthodontics. 8th edition.
m

• Ingle and Bakland. Endodontics. 4th Ed;
Williams and Wilkins, Malvern, 1994.
• Cohen and Burns. Pathways to the Pulp.
8th Ed; Mosby, St. Louis, 2002.
• Operative procedures on mutilated
endodontically treated teeth. J. Prosthet.
Dent., 11 : 973-986
• Principles of preparing endodontically
treated teeth for dowel and core
restorations- J. Prosthet. Dent; Aug 1973
m

• The Prosthodontic use of endodontically
treated teeth:theory and biomechanics of
post preparation. J. Prosthet. Dent; Feb 83
• Management of endodontically treated
teeth, J. Prosthet. Dent; April 1983
• Restoration of endodontically treated teeth
– Dental clinics of North America
• Stockton, W.L. (1999). Factors affecting
retention of post systems. A literature
review. J. Prosthet. Dent., 81 : 380-385.
m

• Sorensen, A.J. and Engelman, J.M.
(1990). Ferrule design and fracture
resistance of endodontically treated
teeth. J. Prosthet. Dent., 63 : 529-
536.
• Stankiewicz, N.R. and Wilson, P.R.
(2002). The ferrule effect : A
literature review. IEJ, 35 : 575-581.
m

Restoration of endodontically treated teeth / dental implant courses

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Restoration of endodontically treated teeth / dental implant courses

Similar to Restoration of endodontically treated teeth / dental implant courses (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Restoration of endodontically treated teeth / dental implant courses