Aesthetic Resin Restorations Flashcards
What are the 3 types of aesthetic resin restorations
Composite resin
Poly-acid modified Resins ( Compomers )
Resin Modified Glass Ionomers
Requirements for ideal composite resin?
Biologically acceptable
Dimensional stability
Acceptable mechanical properties
Acceptable physical Properties
Adhesion to tooth structure using a enamel-dentine bonding system
Insoluble in Saliva
The material must imitate normal tooth structure
Radiopaque
How can polymerization shrinkage be reduced?
Incremental packing,keeping the C-Factor in mind, correct application of the bonding system and the use of highly filled composite resins.
The more organic fillers ,the less organic resin monomer matric —> the less polymerization shrinkage and stress.
How does water absorption affect dimensional stability?
Water absorption results in expansion — which is also referred to as hydroscopic expansion.
This results in the weakening of the bond between the filler particles and resin within the composite
What are some mechanical properties?
Compressive Strength, Tensile strengh, Surface hardness, acceptable physical properties
What are some good aesthetic properties of resin materials
Opaque
Acceptable refraction index
Resistance to discoloration due to food ,smoke
Colour stability
Variation in color for good aesthetics
What are the 4 major components in dental composites resins
An Organic monomer matrix - Di-methacrylate resin monomers
Inorganic dispersed fillers - Glass, quartz, silica
A coupling agent - Saline which adheres the monomer matrix to the filler particles
A polymerization initiator - Camphorquinone to get the process of polymerization started
What are a few organic resin monomers
Bis-GMA resin
UDMA
TMA
4-META
TEGDMA
What are inorganic fillers?
They are either large particles of quartz or small particles of silica or a combination of both
Advantages of filler particles
Fracture resistance increases, the more filler in the composite the more viscous it becomes.
Functions of fillers
Improves mechanical properties
Reduces polymerization shrinkage
Reduces the COTE
Reduce amount of water absorption
Reduces the exothermic reaction
Improves aesthetics
Adds radio-opaque
What is a Coupling agent
It helps to produce a bond between the inorganic fillers and organic monorms matrix.
Silane is a bi-functional molecule as it is capable of reacting with the inorganic fillers, as well as with the organic resin monomer matrix.
What is the critical role of the coupling agent?
Preventing crack propagation
An example of a polymerization initator?
Camphorquinone
An example of a polymerization inhibitor
Butylhydroxytoluene
What does a polymerization inhibitor due?
It prevents premature or spontaneous polymerization of the resin monomers
What are nano-filled/ nano-hybrid composites?
They are extremely small particles, due to their size higher filler levels can be achieved in the restorative materials which results in
improves aesthetics and excellent physical properties
Examples of Nano-filled/nano-hybrid composites
Filtek Supreme ETE, Filtek Z350, Filtek Supreme Ultra universal
What are composites with spherical filler particles
Granulated spherical fillers are used in combination with an optimised resin matrix system
Example - Ceram.X
What is a composite core?
The primary purpose of a core build-up material is to replace missing tooth structure and to permit creation of ideal retention form and resistance form for crown and bridge preparations
Example of composite core
Filtek one bulk fill restorative (3M)
What is condensable composite?
These materials have a very high filler content therefore high viscosity.
only used in posterior teeth
Due to high viscosity there is a potential lack of adaptability.
Flowable composites
These materials contain less filler particles and are therefore not as strong as the universal composite
- they undergoe high polymerization shrinkage due to low filler content
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Example - filtek z350 xte flowable
Flowable are most often used as?
Preventative resin restorations and restoration of attrition facets
