PDF, Biocompatability of Endodontic materils , Classification, Uses , biological requirements , Handling-related requirements , Toxicity, Allergy, Mutagenicity

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Subtitle
BIOCOMPATIBILITY OF
ENDO-DONTIC
MATERIALS
Presented by:
Dr.Hashmat Gul
Demonstrator AMC
Dental Materials
Clinical success rates of RCT = 70–95%
Requirements of RCT success
• physical,
• biological,
• handling-related requirements
Endodontic materials represent only one aspect out of several parameters
that are important for the clinical success of an endodontic treatment
Clinical Data and Biocompatibility

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• No systemic toxicity
• Nonallergenic
• Compatible with local (periapical) tissue
• Sterile or sterilizable
• Antimicrobial activity
( anaerobes, such as Actinomyces strains and Enterococcus faecalis)
A complete biomechanical preparation & the entire removal of the invaded
microbiota are technically impossible due to
The complex anatomy.
Possibility of Deep penetration of bacteria into accessory canals, the
apical “canal delta,” and up to 1 mm into the dentin
• Promotion of periapical healing
The Biological Requirements
Mandibular Nerve Injuries
CAUSES
• Extended overfilling of RC in lower molar.
• Over instrumentation/over preparation.
Handling Related requirements

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Rubber Dam
Should generally be used for each RCT.
Allergies to latex have been document and allergic reactios to these are
mostly type I (immediate) reactions:
1. Localized contact urticaria
2. Anaphylactic shock
Latex-free rubber dams e.g. based on silicone. One recent case of a type
IV reaction to a latex-free rubber dam has been reported
Handling Related requirements
Points Sealer Thermoplastic material
Gutta-percha points
Titanium posts
Silver points
Zinc oxide eugenol (ZOE)
materials
Polyketone products
Epoxy resins
Calcium hydroxide
based materials
Mineral trioxide
aggregate(MTA)
Calcium phosphate
cement
Silicone based sealers
Resin based sealers
Resilon points (resin-
based)
CLASSIFICATION OF ENDO-DONTIC
MATERIALS

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Gutta-percha
Source: Natural product from gutta-percha tree (Isonandra percha).
Chemically GP is a polymer based on isoprene.
Types of gutta-percha
α-GP, which is for injectable techniques
β-GP, used for points.
Gamma-GP, not used in Dentistry
Handling of Gutta-percha
It is not only used for points but is also applied in a thermoplastic
state.
It is either completely or only superficially heated or liquefied in order
to better adapt to the root canal walls.
Thermoplastic gutta-percha is usually combined with a sealer.
Gutta-percha

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COMPOSITION RELEASE &
DEGRADATION
Systemic toxicity
and allergies
Local toxicity
and tissue
compatibility
Antimicrobial
properties
Mandibular nerve
injuries
Zinc oxide:
33–61.5%
Gutta-percha:
19–45%
Heavy metals:
1.5–31.2%
Additives
( colophony): 1–
4.1%
Pigments: 1.5–
3.4%
Zinc ions from
ZnO filler
CaOH
(additive)
Nil No/slight toxic
Foreign-body
immune
response with
some
products.
ZnO
Iodoform :
May cause
toxic/allergic
rxn
Tetracycline
Liquefied
gutta-percha
which
extruded from
the root canal
Overfilling of
gutta-percha
or
chloropercha
can sometimes
cause
parasthesia
Gutta-percha
Fig. A temperature increase of
>10°C for more than 1 min may
cause bone damage
*cervical area
**central root surface area
***root end,
****with sealer
TEMPERATURE AT THE
ROOT SURFACE AFTER
APPLICATION OF HEATED
INJECTABLE GUTTA-
PERCHA

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Zinc Oxide Eugenol Sealer
Type
COMPOSITION
Powder Liquid Additives
Standard ZnO
Eugenol sealer
Zinc oxide 42%
Stabilite 27%
Bismuth carbonate 15%
Barium sulfate 15%
Sodium borate anhydrate 1%
Eugenol Thymol/
Thymoliodide
Hydroxyl apetite
CaOH
Modified ZnO
Eugenol sealer
Zinc oxide 60%
Aluminum oxide 34% Resins
(e.g., colophony 6%)
Orthohydroxy-
benzoic acid
62.5%
Eugenol 37.5%
Zinc Oxide Eugenol Sealer

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RELEASE &
DEGRADATION
Systemic toxicity
and allergies
Local toxicity and
tissue compatibility
Antimicrobial
properties
Mutagenicity &
carcinogenicity
Colonophony
increase the
adhesiveness
adjust the speed
of the setting
reaction
decrease
solubility or
disintegration
Eugenol
Formaldehyde/Pa
raformaldehyde
Eugenol:
Low Systemic
toxicity
Impair nerve
conduction
temporarily
Formaldehyde/Pa
raformaldehyde
paste Overfilling:
Anaphylactic
shock/
Generalized
urticaria
irreversibly
suppresses the
nerve
conduction
Hydroxyl apatite
or CaOH
Eugenol:
Contact
allergin
Highly
cytotoxic
Formaldehyde:
Contact allergen
Aspergillosis of
maxillary sinus
damage to sinus
mucusa with
formaldehyde+
ZnO induce
fungal growth.
Thymol/
Thymoliodide
Formaldehye
Eugenol
Formaldehyde
Irreversible
Paraesthesia of
inferior alveolar
nerve.
Formaldehyde
free ZnO eugenol
sealer_reversible
paraesthesia of
maxillary sinus
Zinc Oxide Eugenol Sealer
COMPOSITION RELEASE &
DEGRADATION
Systemic
toxicity &
allergies
Local toxicity & tissue
compatibility
Antimicrobial
properties
Powder
ZnO 97%
Bi(PO)4 3%
Liquid
Propionylacetophenone
76%
Vinylcopolymers 23.3%
Dichlorophene 0.5%
Tritethanolamine 0.2%
No data are
available
Sets by
chealation rxn.
Nil
Non-toxic after the
material has set.
Mild peri-apical
inflammation when over-
filled in rat molars.
Better compatability to
bone when used in thick
consistency.
+++
Polyketone-based Sealers

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Epoxy-based Sealers
TYPES
AH26,
with silver
silver-free.
AHPlus (also marketed as Top Seal)
RELEASE &
DEGRADATION
Systemic toxicity &
allergies
Local toxicity &
tissue
compatibility
Antimicrob
ial
properties
Mutagenici
ty &
carcinoge
nicity
Mandibular nerve
damage
AH26-
Formaldehyde
released during
setting only.
epoxy monomer_
a contact allergen
Mild/no allergic
erythema of the
face and nape
of the neck
No systemic toxic
reactions
Slight cytotoxic
during setting
+++++ Freshly
mixed_
mutage-
nic.
Parasthesia_exte
nded over-filling
of mandibular
teeth.
Epoxy-based Sealers

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RELEASE &
DEGRADATION
Systemic toxicity &
allergies
Local toxicity & tissue
compatibility
Antimicro
bial
propertie
s
Mutageni
city &
carcinog
enicity
Mandibular nerve
damage
-OH and Ca
ions.
vary from
product to
product.
No systemic or
allergic reactions
reported so far.
Low local toxicity
occur only in initial
period after
application.
hard tissue
formation at the
root apex
observed.
+
no effect
on E-
faecalis
and
candida
albicans
- - -
Mandibular
nerve injuries
seldom occur.
Calcium Hydroxide-based Sealers
Calcium Hydroxide-based Sealers
Fig, a-c Healing of a chronic apical inflammation with osteolysis.
a Root canal debridement.
b Application of a calcium hydroxide material.
c Formation of a hard tissue barrier at the root end

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COMPOSITION : A mixture of
tricalcium silicate
tricalcium aluminate
tricalcium oxide
silicate oxide
TYPES
white (WMTA)
grey (GMTA)
In Grey MTA Al2O3, MgO, and FeO being present in higher concentrations
MIXING & SETTING
The powder is mixed with water, generating a colloidal gel that sets within 3–4 h ,
followed by a maturation period .
Mineral Trioxide Aggregate
RELEASE &
DEGRADATION
Systemic
toxicity &
allergies
Local toxicity & tissue
compatibility
Antimicro
bial
properties
Mutagenicit
y &
carcinogeni
city
USES
CaOH Nil CaOH
Slightlycytotoxic.
Cytotoxicity increased
somewhat over time .
Deposition of new
cementum in open
apex. repairing
furcation perforations.
Small areas of
ankylosis in lateral
perforations.
+++ - - - Root canal sealer
For pulp cappings
Apexification
Sealing of
perforations
Root end filling
Mineral Trioxide Aggregate, MTA

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COMPOSITION
Tetra-calcium phosphate
Di-calcium phosphodihydrate/dehydrated dicalcium
phosphate
MIXING & SETTING
mixed with a 1-molar solution of dibasic sodium phospho-
heptahydrate
LOCAL EFFECTS
No inflammation
Cementogenesis
ANTI-MICROBIAL EFFECT
Very good , ++++
Calcium Phosphate Cement
TYPES
Systemic toxicity &
allergies
Local toxicity &
tissue compatibility
Antimicrobial
properties
C-silicones
(condensation cross-linking silicones)
A-silicones (addition cross-linking),
RoekoSeal.
Gutta-Flow, improved seal by (0.2%)
expansion .
Silver particles added (preservative).
Not
documented.
No/slightly
cytotoxic.
Non-mutagenic.
good.
Little/no
effect on E-
fecalis.
SILICONS

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Resin based sealers have been introduced to
improve the sealing and bonding to root canal
dentin.
These sealers do not adhere to gutta percha so
special points have been developed called Resilon .
It is thermoplastic copolymer of polycaprolactone
and urethane methacrylate.
These points are bonded to the root canal dentin
through a dual curing resin sealer.
RESIN-BASED SEALERS
RELEASE &
DEGRADATION
Systemic toxicity &
allergies
Local toxicity & tissue
compatibility
Antimicrobial
spectrum
Mutagenicity &
carcinogenicity
Scarce
information.
Nil slightly to
moderately
cytotoxic.
Well tolerated in
periapical tissue.
not much
broad
Nil
RESIN-BASED SEALERS

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Fig. Local toxicity of
different root canal filling
materials in implantation
tests.
Low toxicity (= low
toxicity index) of gutta
percha
Decreasing toxicity of
an epoxy sealer with
increasing aging time
TOXICITY INDEX
MATERIALS FOR RETROGRADE ROOT
CANAL FILLING

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REQUIREMENTS
Excellent sealing capacity
Stimulation of hard tissue formation
Stability in a humid environme
USES
A surgical procedure that is associated with
early exposure of a comparatively large
surface area to humidity and the presence of
a bony defect.
Where a regular endodontic access cavity is
often not possible,e.g. in presence of
endodontic post which cant be removed.
MATERIALS FOR RETROGRADE
ROOT CANAL FILLING
CLINICAL DATA
Amalgam and silver points are no longer recommended
for retrograde root canal fillings.
Modified ZOE materials and light-curable glass ionomer
cements as well as polyketone-based sealers (possibly in
combination with preformed inserts) are better
alternatives.
MTA shows very promising results, but more clinical data
are necessary. If these data are positive, MTA can be
recommended for retrograde fillings.
MATERIALS FOR RETROGRADE ROOT
CANAL FILLING

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RETROGRADE ROOT CANAL FILLING
Fig. a,b Treatment after extrusion of a root canal sealer into the mandibular canal.
a Situation after excessive overfilling of a lower left first molar.
b Situation after surgical removal