composite resin dental material
DESCRIPTION
composite resin dental materialTRANSCRIPT
Direct Esthetic Direct Esthetic Restorative MaterialsRestorative Materials
Both silicate cement and acrylic resin (PMMA) are Materials from History
Science of Science of Resin Resin
CompositesCompositesFor Direct RestorationsFor Direct Restorations
• Materials made up of 2 /+ distinct, chemically different phases
• The resulted material (composite) combine the properties of the phases included
Examples • Jell-o & fruits• Concrete• Tooth enamel and
dentine• Resin composite
Composite !!! What does it mean?
Dental Resin Composites
Matrix phase
Dispersed phase(fillers)
1. Organic phase (matrix)2. Inorganic dispersed
phase (fillers)3. Coupling phase
1. Polymerization-associated additives
2. Coloring additive3. Ultraviolet stabilizers4. Radioopacifiers
+
Coupling phase
Organic Phase (Resin Matrix )
Function
1. Hold all ingredients in one mass
2. Able to polymerize (Responsible for material’s setting )
3. Accept pigments (Responsible for material’s color )
4. Responsible for the setting contraction
1. Monomer system
- BIS-GMA or UDMA. (viscous monomers)
- Silorane resins (in the most recent, minimal-shrink type)
2. Diluents
- TEGDMA & HEMA
Dispersed Phase (Fillers )
Function1. Mechanical Prop.
2. Wear resistance
3. Coeff. of th. Exp.
4. Poly. shrinkage
1. Inorganic fillers 1. Inorganic fillers - Quartz, glass, barium and lithium - Quartz, glass, barium and lithium
alumino-silicates, barium fluoridealumino-silicates, barium fluoride
- Zinc (Zn), Boron (B), zirconium (Zr) - Zinc (Zn), Boron (B), zirconium (Zr) and yttrium (Y) ions and yttrium (Y) ions are added to are added to produce radioopacityproduce radioopacity
2. Pre-polymerized organic fillers2. Pre-polymerized organic fillers - Ground resin composites- Ground resin composites
3. Alternative fillers 3. Alternative fillers - fibers, tri-modal, non-slumping fillers, - fibers, tri-modal, non-slumping fillers,
fluoride-releasing – Nano-sized fluoride-releasing – Nano-sized fillersfillers
Classification based on filler size and loadingTypes Filler size Filler load
Traditional types
1. Macro-filled 8-12 µm 75-80 wt%
2. Small particle 1-8 µm 70-85 wt%
3. Hybrid 0.4-1 µm 70-75 wt%
4. Micro-filled 0.04-0.4 µm 50-60 wt%
Recent types
5. Nano-hybrid 0.02-2.5 (Av 0.6) µm 70-75 wt%
6. Nano-filled Culsters- 0.06-1.4 µm (5-20 nm)
70-75 wt%
Macro-filled Small-particle Hybrid Micro-filled
Anusavice K. Phillip’s Science of Dental Materials 2003
Property Traditional Microfilled Small P. Hybrid
Compr. strength (MPa) 250-300 250-300 350-400 300-350
Tensile strength (MPa) 50-65 30-50 75-90 70-90
Elastic Modulus (GPa) 8-15 3-6 15-20 7-12
Coeff .Th. Exp. (10-6/ºC) 25-35 50-60 19-26 30-40
Knoop Hardness 55 5-30 50-60 50-60
Properties of traditional Composites
Quoted from: Deliperi S, Bardwell d. J Am Dent Assoc. 2002; 133:1387-1398
Quoted from: Deliperi S, Bardwell d. J Am Dent Assoc. 2002; 133:1387-1398
Coupling Phase
1.1. Vinyl triethoxy silane (vinyl silane)Vinyl triethoxy silane (vinyl silane)
2.2. γγ--Methacryloxy propyl trimethoxy SilaneMethacryloxy propyl trimethoxy Silane
Mechanism of attachmentMechanism of attachment
-- They are composed of They are composed of bi-functional moleculesbi-functional molecules
- The - The silane groupsilane group chemically bonds to the inorganic chemically bonds to the inorganic materialsmaterials
- Both the - Both the ethoxy and methoxyethoxy and methoxy groups groups react with resin react with resin molecules of the matrixmolecules of the matrix
FunctionFunction
1.1. The water uptakeThe water uptake
2.2. The solubility rateThe solubility rate
3.3. The crack propagationThe crack propagation
Bonding of fillers to resin matrix
Polymerization associated additives
Polymerization initiator….Polymerization initiator…...1.1. Benzoyl proxideBenzoyl proxide in case of chemical and heat- in case of chemical and heat-
cured materialscured materials
2.2. CamphroquinonCamphroquinon in case of light-cured materials in case of light-cured materials
Polymerization activator…Polymerization activator…Tertiary amineTertiary amine in in case of chemically-cured materialscase of chemically-cured materials
Polymerization inhibitor… Polymerization inhibitor… (hydroquinon)(hydroquinon) prevents material’s polymerization on storageprevents material’s polymerization on storage
Chemically-Cured CompositeChemically-Cured Composite
Effect of classical curing techniques on composite properties
Difference Chemical-cured (CC) Light-cured (VLC) Heat-Cured (HC)
• Presentation forms 2 paste (Base & Catalyst)
Single paste (Syringe, capsules)
- 1 paste- Powder and liquid
• Mixing Mixing of equal parts of base and catalyst over paper pad by the use of plastic spatula
No mixing is required (only direct dispensing from either the syringe or capsules)
Mixing of P&L form only
• Setting reaction Addition polymerization Addition polymerization Addition polymerization
• Polymerization initiator
Benzoyl peroxide Camphroquinon Benzoyl peroxide
• Polymerization activator
- 3ry amine (old)- N-dihydroxy ethyl–P-
toluidine
UV light, Blue VL, or Laser
Heat, or Heat&pressure
• Method of application
Direct, using bulk technique
Direct, using incremental technique
Indirect (Laboratory processed)
Property Chemical-cured (CC) Light-cured (VLC) Heat-Cured (HC)
• Working time - Limited- The chemical reaction starts once base and catalyst are mixed
- Unlimited- The chemical reaction starts when the material is subjected to light
- Unlimited- The chemical reaction starts when the material is subjected to heat
• Degree of polymerization
Higher than VLC and lower than HC
The lowest The highest
• Residual Monomer• (act as plasticizer)
Lower than VLC and higher than HC
The highest The lowest
• Polymerization shrinkage
Higher than VLC and lower than HC
The lowest The highest
• Strength and hardness
Higher than VLC and lower than HC
The lowest The highest
• Porosity Voids could exist as a result of air trapping during mixing
Less Than CC (No Mixing)
Less than CC (Depending on the packing technique)
• Color stability The lowest, due to presence of 3ry amine and porosities
Higher than CC and lower than HC
The highest
• Bonding to resin bonding agents
Lower than VLC and Higher than HC
The highest The lowest
• UV stabilizers… UV stabilizers… ((2-hydroxy-4- methoxy 2-hydroxy-4- methoxy benzophenone) benzophenone) Provide color stability under Provide color stability under electro-magnetic waveselectro-magnetic waves
• Coloring agents (Pigments)….Coloring agents (Pigments)…. To To provide materials with different shadesprovide materials with different shades
Other Additives
Listen, always keep these
Clinical Hints in your mind
Composite polymerization is retarded in presence of
Eugenol and oxygen.
It is mandatory to incrementally insert the light-cured material
The chemically-cured materials is no longer be used clinically
Mechanical, Micro-mechanical and inter-penetration means help the composite retain to the tooth structure
Direct applications of resin composites Filling class III, IV, V and VI cavities in anterior teeth Filling small and moderate Class I, II, V cavities in post. teeth Core build-up (strengthening of weakened teeth) Diastma Closure Direct laminate veneer
1. Esthetic.
2. Conservative cavity.
3. Low thermal conductivity.
4. Quite resistance to microleakage
5. No corrosion.
6. Strengthening of the remaining tooth st.
1. Polymerization shrinkage.
2. High coefficient of thermal expansion
3. Pulp irritation due to residual monomer ……i.e. deep cavities should be protected
4. Low wear resistance.
5. Technique sensitive.
Advantages
Disadvantages
Step By Step Restoration
Done
What do you exactly know about
the modified types of composite restoratives ?