Liner Bases & Varnishes short but in depth knowledge

1. DEPT. OF
CONSERVATIVE DENTISTRY
&
ENDODONTICS 8 June 2016
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2. CAVITY LINERS AND
BASES
Presented by-
Dr NISHANT KHURANA
PG Student
Guided By:- Dr M.P. Singh
&
Dr Hemant Chourasia
8 June 2016
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3. CONTENTS
• Introduction
• Causes of pulpal pain
• Objectives for pulpal protection
• Classification of Intermediary bases
• Ideal requirements of intermediary bases
• Solution liners (varnish)
• Suspension liners
• Cement liners
• Cement base
• References
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4. INTRODUCTION
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5. STEPS OF TOOTH PREPARTION
INITIAL TOOTH PREPARTION
STAGE
• STEP 1:- OUTLINE FORM & INTIAL
DEPTH
• STEP 2:- PRIMARY RESISTANCE FORM
• STEP 3:- RETENSION FORM
• STEP 4:- CONVENIENCE FORM
FINAL TOOTH PREPATION
STAGE
• STEP 5:- REMOVAL OF ANY
REMAINING INFECTED DENTIN OR OLD
RESTORATIVE MATERIAL
• STEP 6:- PULP PROTECTION
• STEP 7:- 2ND RESISTANCE & RETENTION
FORM
• STEP 8:- PROCEDURES FOR FINISHING
EXTERNAL WALLS
• STEP 9:- FINAL FINISHING
9 STEPS WITH 1 GOAL
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6. PULP PROTECTORS:- LINER, BASES & VARNISH
Main reason for using a liner or base is to protect the pulp
or to aid pulpal recovery or both.
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7. Q WHY DOES A TOOTH ACHE ??
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8. • the pulp communicates with
the fluid inside the dentinal
tubules , and if there is
disturbance in the dentinal
fluid it can be sensed by the
pulp as pain
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9. • Pulp Protection requires consideration of:-
1. Sealing the smear layer
2. Chemical protection
3. Electrical protection
4. Thermal protection
5. Mechanical protection
6. Pulpal medication
OBJECTIVES OF PULPAL PROTECTION
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10. SEALING THE SMEAR LAYERS
• Tooth preparation with rotary
instruments generates cutting debris,
some of which is compacted
unavoidably into a layer on the cut
surface. This layer of material is called
SMEAR LAYER & is typical of any cut
surface, dentine or otherwise.
• Its 25-30% porous & can not prevent
Slow Long Term Diffusion
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11. 8 June 2016
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12. PULP PROTECTION AGAINST
Thermal insult
Electrical insult
Chemical iritant
Mechanical protection
Pulpal medication
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13. RELATION BETWEEN DENTIN
PERMEABILITY & PULP PROTECTION
• Dentin permeability increase as remaining dentin thickness decrease towards
the pulp.
• Factors which influence the need for pulp protection
- depth of the cavity
- location of walls & floor relative to the pulp horns
- surface condition of dentin.
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14. CLASSIFICATION OF INTERMEDIARY
BASES
 According to Marzouk
1. Varnishes
2. Liners
3. Sub base
4. Bases
• According to Sturdevant
1. Liners:-- Thin
a) Solution liners (varnish 2-5 µm)
b) Suspension liners (20-25 µm)
- Thick – cement liners
2. Bases
• According to Charbeneau
1. Cavity varnish
2. Intermediary bases (liners)
3. Cement bases.
• According to Schwartz
1. Cavity sealers
- varnish
- resin bonding agents
2. Liners
3. Bases.
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8 June 2016

15. IDEAL REQUIRMENTS
• The material should create an impervious layer.
• Biologically & Chemically compatible.
• Should not discolor tooth or restorative material.
• Should harden quickly.
• Should withstand the condensation forces.
• Should stabilize or diminish dentin permeability.
• Should be easily manipulated.
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8 June 2016

16. CAVITY LINERS
Definition:
 Anusavice – Thin layer of cement such as calcium hydroxide suspension in an aqueous or
resin carrier used for protection of the pulp.
 Sturdevant – Thin layers of material used primarily to provide a
barrier to protect the dentin from residual reactants diffusing out
of a restoration or oral fluids (or both) that may penetrate
leaky tooth restoration interfaces.
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17. • Liners can be classified on the basis of their film thickness into:
- Thin film liners
a) Solution liners (varnish 2-5 µm or 0.002- 0.005mm)
b) Suspension liners (20-25 µm or 0.02-0.025mm)
- Thicker film liners
cement liners(200-1000 µm or 0.2 to 1 mm)
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18. VARNISHES (SOLUTION LINERS)
• Def:- Any liner based on non-aqueous solvents that rely on evaporation for
hardening is designated as a solution liner(or Varnish).
• Copal or natural resin dissolved in non-aqueous volatile solvent, (ether,
alcohol and acetone) upon drying it will produce a thin film layer.
• ADVANTAGES:- flexible – dry rapidly.
• On the other hand, thick films tend to trap solvent during drying and
become brittle.
[2-5 µm]
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19. COPALITE VARNISH OCCLUDING
DENTINAL TUBULES
[Courtesy of SC Bayne, school of dentistry, University of Michigan, Ann Arbor, MI] 8 June 2016
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20. VARNISH [COPALITE]
Composition
 Natural gum – copal resin
 Synthetic resin – nitrated cellulose
 Solvents
 Medicinal agents – chlorobutanol, thymol &
eugenol.
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21. FUNCTIONS
• Prevents microleakage.
• Reduces post-operative sensitivity.
• Prevents penetration of toxic materials.
• Does not act as an insulator.
Properties:
Neither possess mechanical strength nor provide thermal
insulation.
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22. INDICATIONS:
- Enamel & dentin walls – reduce the
penetration of oral fluids around
metallic restorations.
- Over metallic restoration – reduce post-
operative sensitivity
- Dentinal walls – minimize penetration of
acid from zinc phosphate cements.
CONTRAINDICATIONS:
 1-Under silicate cement → as it blocks the transfer of
fluoride ions from silicate cement to tooth.
 2-Under glass ionomer cement and polycarboxylate
cement as it prevents or decrease their adhesiveness
to tooth structure.
 3-Under resinous restorations as acrylic resin and
composite → as the residual monomer will dissolve
the varnish destroying the integrity of the varnish
film, which will be of no value to be used.
 4-In moderately deep and deep cavities → as it does
not provide thermal insulation property.
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23. METHOD OF APPLICATION
• Dry the cavity
• Soak a small cotton pellet with varnish
• Squeeze at one corner of cavity without moving it
• Soak it again and squeeze it again at another
corner of cavity, do it till a continuous film
is formed over cavity walls
• Dry it for 2 to 3 min
• Usually 3 applications are sufficient
• Also applied with camel brush
• Thickness 2 -5 microns
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24. COPAL- F
• Protective varnish containing 5% Sodium Fluoride based on Copal
gum for insulating exposed dentine and providing thermal barrier.
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25. CERVITEC® PLUS- IVOCLAR
VIVADENT N.A.
-Chlorhexidine Varnish
-Protect exposed root surfaces
-Treat of open dentin tubules
-1% chlorhexidine and 1% thymol in a homogenous
solution
-Colorless, transparent clear varnish
-Provides optimum esthetics in the anterior
part of the mouth
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26. CAVITYSHIELD™ 5% NAF VARNISH - 3M
ESPE COMPANY
• Bubblegum flavor
• Enhanced asepsis
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27. SUSPENSION LINERS
• Def:- Liners based on water have many of the constituents
suspended instead of dissolved & are called suspension liners.
• Ca(0H)2 or zinc oxide in a synthetic resin
• Water solvent based; H2O soluble
• 10-25 µm film; Used to line only the dentin
[20-25 µm]
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28. Solution Liner/Varnish
-Organic solvent based
-H2O insoluble
-2-5 µm
-Used to line cavity up over cavosurface
margins
- They are flexible and dry rapidly
Suspension liner
-Water Solvent based
-H2O soluble
-20 – 25 µm
-Used to line only the dentine
- Dry more slowly and produce
thicker film
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8 June 2016

29. CEMENT LINERS
• Def:- Thicker liners that are selected primarly for pupal medication & thermal
protection are sometimes identified as cement liner.
[200-1000 µm = 0.2-1mm]
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30. FUNCTIONS:
1. Primary purpose  protective seal of
exposed dentin surface.
2. Electrical insulation (with newly placed
amalgam restoration) from the electrical
circuts with restorations in adjacent teeth.
3. Thermal insulation with metallic
restoration
4. Pulpal medication
COMPOSITION:
- Suspension of calcium hydroxide
- methyl ethyl ketone or ethyl alcohol
- Methyl cellulose – thickening agent
- acrylic polymer beads or barium sulfate
- Calcium mono-fluoro-phosphate.
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31. ZINC OXIDE LINER
- Used in moderately
deep cavities.
- Palliative or obtundant
effect
- Not used under
composite restorations.
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32. CALCIUM HYDROXIDE LINER
- Forms reparative dentin
- Used under composite restorations
- In deep cavities
- In exposures or suspected exposures.
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33. MANIPULATION OF CA(OH)2
 Sqeeze equal parts of Ca(OH)2
paste, mix homogenously
Make a bead and carry with
applicator, allow it to flow on the
surface of concavity created by caries
and dry for 2-3 min
If in Powder form carry with tweezer
and repeat till it occupies required
dimensions
If in suspension form-Injectible ,Drop
it on the site indicated
Thickness-1-50microns for solution
liners and suspension liners 20-25
microns 8 June 2016 33

34. Calcium
hydroxide
Glass ionomer Reinforced
ZOE
Components Paste with
Ca(OH)2,LC resin
& polyphenols
Powder(Al-
silicate)liquid(po
lyalkenoate
acid,LC resin)
Paste (with ZnO)
paste (with
eugenol)
Thermal
conductivity
Insulator insulator Insulator
Solubility 0.3-0.5% high 0.08%(low) modest
Compressive
strength
138 Mpa 128 Mpa 71 Mpa
Elastic modulus 588 Mpa 1820 Mpa -----
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35. CAVITY BASES
• Definition:-
Anusavice – Layer of insulating, sometimes medicated, cement,
placed in the deep portion of the preparation to protect pulp
tissue from thermal & chemical injury.
Marzouk – Insulating materials that can be used directly on
certain areas of the dentinal parts of the preparation.
Sturdevants- Bases(1 to 2 mm) are used to provide thermal protection for
the pulp and to supplement mechanical support for the restoration by
distributing local stresses from the restoration across the underlying dentin
surface.
[1-2mm]
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36. • TYPES
- High Strength Bases
Provide thermal protection for pulp & mechanical support
for the restoration.
Eg:Zn phosphate,Zn poly carboxylate,Glass ionomer,RMGI
-Low Strength Bases
Have min strength & rigidity, Act as a barrier to irritating
chemicals and to provide therapeutic effect to pulp.
eg: Ca Hydroxide, ZnOE
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37. HISTORICAL BACKGROUND:
• Before 1960’s Zn phosphate cement
Reinforced ZnO/E
• 1970 polycarboxylate cement
• 1985-1994 GlC
• Light Cured GIC & compomers chemical adhesion, Good
mechanical properties, fluoride release, command setting and rapid
achievement of strength.
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38. Zinc
phosphate
Zinc
polycarboxylate
ZOE Calcium
hydroxide
GIC
Composition
And setting
Reaction
P-Zinc
oxide, L-
(phosphori
c acid)
P- Zinc oxide
liquid(polyacrylic
acid)
P-zinc oxide
L- eugenol
Base paste
Catalyst
paste
P, F-Al-Si glass
L- polyacrylic
acid
p/L ratio 1.4 g/0.5
ml
1.5/1 6/1 by weight 1/1 3/1 by weight
Setting time 2.5-8 min 6-9 min 4- 10 min 2.5- 5.5 min 3- 5 min
Compressive
strength
104 Mpa 55- 67 Mpa 4- 55 Mpa 10-27 Mpa 128 Mpa
Diametral
tensile
strength
5.5 Mpa Slightly higher
than ZnPO4
0.3- 5.3 Mpa 1 Mpa 6.6 Mpa
Modul
Of
Elastcty
13.7 Gpa 2.4 -4.4Gpa
Not brittle as
ZnPO4
0.2- 5.4
Gpa
0.37 Gpa …..
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39. GENERAL APPLICATIONS
1. Thermal and chemical insulation
2. Temporary restorations – Zn OE
3. Intermediate restorations – IRM
4. Permanent restorations – GIC
5. Temporary Luting – Type I ZOE
6. Permanent Luting – GIC, ZnP, Zn Poly Carb
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40. SUMMARY OF PULP PROTECTION
PROCEDURES
Shallow Excavation
[RDT > 2mm]
Moderate Excavation
[RDT 0.5 - 2mm]
Deep Excavation
[RDT < 0.5mm]
Amalgam -/-/Sealer -/base/sealer Dycal/base/sealer
Composite -/-/DBS -/-/DBS Dycal/-/DBS
Gold inlays &
onlays
-/-/cement -/base/cement Dycal/base/cement
Ceramics -/-/DBS, CC -/-/DBS, CC Dycal/-/DBS, CC
(Medicament / Liner / Sealer) 8 June 2016
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41. SCHEMATIC DIAGRAM FOR
AMALGAM RESTORATION
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42. REFERENCES
• Philps’ science of dental materials – 11th edition
• Basic Dental Materials- Mannapallil
• Restorative dental materials – Craig
• Sturdevant’s art & science of operative dentistry – 5th edition
• Operative dentistry – Marzouk
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