06.liners and bases
TRANSCRIPT
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o Healing/ Repair.
o Pulp’s vitality and function.
o Normal responsiveness to
electrical and thermal pulp tests.
o Preventing breakdown of the
peri-radicular supporting tissue.
oFormation of secondary dentine.
Importance of remaining dentin thickness
0.5 mm
1 mm
2 mm
Remaining dentin
thickness
25 %
10 %
Minimal or Nil
Effect of toxic
substances
Causes of Pulpal Inflammation
Types of stimulus Examples of stimulus
Physical Thermal, electrical
Mechanical Handpiece,
traumatic occlusion
Chemical Dental materials, Caries
Biologic Bacteria from saliva
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•Immature permanent teeth or
mature permanent teeth with
simple restorative needs.
II- Indications of direct pulp capping
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Small pinpoint pulp exposure=1mm
•Recent traumatic (<24 h)/Mechanical pulp
exposure
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•Little or no bleeding at the exposure site
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•NO PULP
VITALITY
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•No pulp calcification
•Inflammatory signs/ symptoms 13
•primary teeth root resorption
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•Pre-operative
tooth sensitivity
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•Large
pulp exposures
•Uncontrolled
bleeding
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•Non-restorable tooth
or restorable with low
prognostic
Dentin Bridge
Classification and types
• CAVITY SEALERS: Varnish, Adhesive sealers
• CAVITY LINERS: Glass ionomer, Calcium hydroxide
• Bases: - 1. Zinc phosphate cement.
2. Reinforced zinc oxide / eugenol cement.
3. Zinc polycarboxylate cement.
4. Glass ionomer cement.
Cavity sealers
• Varnish
• Adhesive sealers
• Provide protective coating and barrier to leakage
• Coat all walls of the cavity
• Provide various degrees of seal
Varnish
• Material applied in thin film thickness usually 2 –5 microns.
• It could be applied to all prepared cavities on both enamel and dentin.
• Protective coating and Barrier to leakage
• Seals the dentinal tubules and reduces leakagearound a restoration.
• Provides no thermal
insulation
Varnish
Composition:
• Organic resin or synthetic gum dissolved in solution of ether, chloroform or acetone.
• This solution evaporates rapidly after placement on the tooth leaving a thin layer of semi-permeable membrane.
• The thickness of this layer is 5 – 25 microns depending on the type of the solvent and the number of applications.
• Application process
– Applied with either a small disposable applicator or a cotton pellet.
– Thin coating of the varnish on the walls, floor, and margin of the cavity preparation.
– Apply a second coat.
Contraindication:
- Composite – free monomer layer dissolves the varnish
- Ca(OH)2/ ZOE beneficial affects are lost
- Polycarboxylate – interferes with adhesion
- GIC – blocks fluoride penetration.
Adhesive sealers
• Provide sealing as well as bonding at the interface between restoration and cavity preparation walls.
Concerns about use of adhesive sealers under amalgam
• Barrier to corrosion products
• More technique sensitive than varnishes
• Expensive and time consuming
• Pooling of resin
• Incorporation into amalgam
Liners:
Definition: It is liquid in which CaOH and zinc oxide
(occasionally) are suspended in a solution of natural
or synthetic resins.
Composition:
1. Ca(OH) / ZnO – Therapeutic agent
2. Ethyl alcohol – Solvent
3. Ethyl cellulose – Thickening agent
4. Barium sulfate – Radiopacifier
5. Fluorides – Anticariogenic
Manipulation:
Trade names: Dycal and Life
It is available as 2 paste systems both of which contain
Ca(OH) and one consists of accelerator
Equal amounts of material from each tube is collected over a
glass slab or mixing pad with help of probe (Applicator) both
are mixed till homogeneous colour is achieved and with
same instrument it is carried.
- to deepest portion of the cavity and since it is fluid in
consistency it readily flows or gets painted over the cavity
over which the thermal insulating base or temporary
restoration is provided.
Properties:
1. Acts as a thin barrier between the restoration and theremaining dentine and protects the pulpal tissue fromirritation caused by physical, mechanical, biological, orchemical agents .
2. Like cavity varnish it neither possesses mechanical propertiesnor provides thermal insulation.
3. Should not be applied on cavity margins.
Uses:
1. As pulp capping agent due to its sealing ability.
2. As anticariogenic cement because it stimulates the production of secondary or reparative dentin.
3. Prevents post operative sensitivity or pain.
4. It is compatible with all types of restorative materials.
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IV- Pulp capping materials
•Calcium Hydroxide Ca(OH)2
•Mineral TrioxideAggregate MTA
•Tri-calcium phosphate
•Bioaggregate
•Biodentine
•Bonding Systems
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•The most common direct
pulp-capping agent
•Antibacterial and
disinfects the superficial
pulp
•High pH (about 12.5)
Pure Calcium
hydroxide
Calcium hydroxide Ca(OH)2:
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How does Ca(OH)2 work??
•Liquefaction necrosis of the superficial pulp
•Neutralization of toxicity in deeper layers
•Coagulative necrosis…Irritation of adjacent
pulp
•Minor inflammation response… Hard tissue
barrier
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•Pure calcium hydroxide are more
caustic than Hard-setting calcium
hydroxide pastes (Dycal, Life,…)
but both have been shown to
initiate the same type of healing
Properties:
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• Dentin bridges beneath calcium
hydroxide pulp caps contain ‘tunnel
defects’, therefore an additional
base material is necessary to seal the
exposed pulp from the external
environment.
•Calcium hydroxide materials tend to soften, disintegrate,
and dissolve over time.
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Mineral Trioxide Aggregate or MTA:
ProRoot
To seal communications between
the root canal system and the
external tooth surface at all
levels and recently indicated in
pulp treatment as direct pulp
capping.
Dr M.Torabinejad
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Composition:
•Tricalcium silicate
•Tricalcium aluminate
•Tricalcium oxide
•Silicate oxide
Mixed with sterile water in a 3:1 powder-to-liquid ratio,
MTAsets in 5 minutes
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Application of MTA
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Properties:
•Low or no solubility
•PH value10.2 after mixing and rises to 12.5 after 3 hours
•Antibacterial effect
•Induces pulpal cell proliferation
•Stimulation of mineralized tissue formation
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Process not yet known
Tri-calcium oxide + tissue fluids = calcium hydroxide
Hard-tissue formation
How does MTAwork??
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Tri-calcium phosphate:
- Bone regeneration procedures (promotes effects on
hard tissue formation by osteoblasts)
- Studies showed that dentinal bridge
formation does take place, by direct apposition, on the
pulpal wall
The bridge:
•Contiguous
•Thick
•Minimal pulpal inflammation
•Odontoblasts directly under and in contact with the
bridge
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Bio-Aggregate
Indicated as:
• Repair of Root Perforation
• Repair of Root Resorption
•Apexification
• Pulp Capping
Bio-Aggregate is a root canal
repair material composed of
bio-ceramic nano-particles
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Pure white powder and liquid mixed together to form
a thick paste-like mixture.
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Biodentine™ :
Active Biosilicate
Technology™ /calcium
Silicate based cement
Dentin substitute from Septodont
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Indications:
•Endodontic indications (repair of perforations or
resorptions, apexification, root-end filling)
•Permanent dentine substitute and temporary enamel
substitute
•Restoration of deep or large crown carious lesions
•Direct pulp capping in adults presenting healthy pulp
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Formulation:
Powder
Tri-calcium Silicate (C3S) Main core material
Di-calcium Silicate (C2S) Second core material
Calcium Carbonate and Oxide Filler
Iron Oxide Shade
Zirconium Oxide Radiopacifier
Liquid
Calcium chlorideAccelerator
Hydrosoluble polymer Water reducing agent
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1-Anesthesia
2- Rubber dam
VI- Techniques of direct pulp capping
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3- Chlorhexidine solution
4- Rinse with anesthetic or sterile saline
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5- sterile cotton
pellet to control
bleeding
6-Mix capping agent
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7-Apply to exposure site
8- Base/liner then restore
The bestPermanent filling process consists of
covering the pulp capping material with a RMGIC
followed by a hermeticcomposite resin
restoration to prevent bacterial leakage and
recontamination of the exposed area.
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Bases
• Insulation
• Bulk build up
• Blocking of undercuts
• Resin composite exhibits low thermal diffusivity that a thermal insulating base should be unnecessary
• Insulating base for thermal protection should be used under metallic restorations
• Thickness 0.5-0.75 mm