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DENTURE LINING MATERIALS
By,Head of Department
Dr Khawaja Rashid HassanRawal college of Dentistry
Islamabad
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DENTURE LINING MATERIALS In cases where fitting surfaces of
acrylic dentures needs replacement to improve the fit of the denture.
Classified into 3 main groups1. Hard reline materials.2. Tissue conditioners.3. Soft lining materials.
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1. HARD RELINE MATERIALSChair side relining technique is
used.Divided into 2 types.Both types are categorized as
auto polymerizable resins.Both types polymerize easily at
mouth or room temperature.
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1. HARD RELINE MATERIALS Composition
TYPE 1POWDER POLYMER BEADS POLYMETHYLMETHACRYLATE
INITIATOR BENZOYL PEROXIDEPIGMENTS INORGANIC SALTS
LIQUID MONOMER METHYLMETHACRYLATEPLASTICIZER Di-n-butylphthalateCHEMICAL ACTIVATOR
TERTIARY AMINE
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1. HARD RELINE MATERIALS Composition
TYPE 2POWDER POLYMER BEADS POLYETHYLMETHACRYLATE
INITIATOR BENZOYL PEROXIDEPIGMENTS INORGANIC SALTS
LIQUID MONOMER BUTYLMETHACRYLATECHEMICAL ACTIVATOR TERTIATY AMINE
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1. HARD RELINE MATERIALS
MANIPULATION: Grinding away some of the hard surface
of acrylic base. Powder and liquid are mixed. Applied over the fitting surface of the
acrylic base. Seated into the patient’s mouth. Closed mouth technique is used. Not allowed to remain in the patient ‘s
mouth throughout setting.
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1. HARD RELINE MATERIALS
PROPERTIES:1. Direct contact with the oral tissues is a
disadvantage.2. Methyl methacrylate in the monomer may
cause allergic reaction.3. Low values of glass transition temperature
(Tg) in both type 1 and type 2 materials.4. May become porous due to air entrapment
during mixing.5. Operator has little control over the
thickness of the material.
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2. TISSUE CONDITIONERS Soft denture liners. Applied to the fitting surface of the
denture. Provides cushion to the fitting
surface. Plastic flow continues for 24-36
hours after mixing. Several applications in denture
works.
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2. TISSUE CONDITIONERSOften applied to the dentures of
the patients undergone surgery.In case of immediate dentures,
Addition of the tooth into the denture base that needs to be extracted.
Can be used as functional impression material.
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2. TISSUE CONDITIONERS
COMPOSITION
POWDERPOLYMER BEADS
POLYETHYMETHACRYLATE
LIQUIDSOLVENT ETHYL ALCOHOLPLASTICIZER BUTYLPHTHALYL
BUTYLGLYCOLATE
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2. TISSUE CONDITIONERS
COMPOSITIONAmount of solvent and
plasticizer is very crucial.7.5% - 40% of liquid contains
alcohol.Powder may be pigmented or
unpigmented.
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2. TISSUE CONDITIONERS
MANIPULATION On mixing powder and liquid, physical
process occurs. Smaller polymeric beads get dissolved and
larger beads swell up on absorbing solvent. Final set material is gel-like. High methacrylate, ethyl methacrylate,
plasticizer and solvent gives softness. Normally denture and patient’s soft tissues
are inspected after 2-3 days.
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2. TISSUE CONDITIONERS
PROPERTIES: Initially very soft and Viscoelastic. Undergo permanent deformation under
even small load. Material do not remain permanently soft. Time taken for the material to become
hard and loose the cushioning effect varies from days to a couple of weeks.
Conditioner should be replaced after 2- 3 days till the tissue has healed properly.
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3. SOFT LINING MATERIALS Can be sub divided intoa) Temporary soft lining
materials.b) Permanent soft lining
materials.
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3. SOFT LINING MATERIALS
TEMPORARY SOFT LINING MATERIALS:
Almost similar to tissue conditioners. Supplied as powder liquid formulation. Composition and manipulation same as
tissue conditioners. Retain their softness for longer
duration.( upto a month or two) Selection of denture cleanser is very
crucial for temporary soft liners.
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3. SOFT LINING MATERIALS
PERMANENT SOFT LINING MATERIALS:
Commonly used in patients that cannot tolerate a hard base.
In patients with thin mandibular mucosa.
These materials should remain permanently soft for the life time of the denture.
Elasticity of these materials is very important.
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3. SOFT LINING MATERIALS AVAILABLE MATERIALS:1. ACRYLIC:
Heat cure. Cold cure.
2. SILICONE: Heat cure. Cold cure.
Condensation. Addition.
3. POLYPHOSPHAZINE:
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3. SOFT LINING MATERIALS Heat cure acrylic is in powder liquid
formulation. Powder consist of poly ethyl or poly
butyl methacrylate. Liquid consists of butyl methacrylate
and plasticizer. Dough is formed which is then heat
treated.
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3. SOFT LINING MATERIALS Heat cure silicone is used in the same
way as heat cue acrylic. Presented in a single paste formulation. Paste consist of poly di methylsiloxane
polymer. The 2 cold cure silicone elastomers are
similar to the silicone elastomers used as impression materials.
Cold curing silicones are cured at room temperature.
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3. SOFT LINING MATERIALS
POLYPHOSPHAZINE: Supplied in sheet form. Polymerize by heat cure. Curing cycle can be,
74°C for 8 hours.OR
74 °C for 2½ hours followed by 100 °C for 30 minutes.
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3. SOFT LINING MATERIALS
PROPERTIES: All types are soft and give an adequate
cushioning effect. Cushioning effect depends upon the
thickness of material. 2-3 mm is sufficient for adequate cushioning
effect. Harden through loss of alcohol and leaching
of plasticizer. Adequate bond with the denture base. Denture cleansers effect the soft liners.
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.THANKYOU
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