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25 Cards in this Set
- Front
- Back
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Know chart
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GIC vs. Comp
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What are key components of GIC powder/liquid?
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glass- silica, alumina and fluoride salts
liquid- polyacrylic acid, water, modifiers |
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GIC key points
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setting reaction is acid-based- polyacid attacks glass particles and set cement consits of...
residual glass prarticle cores surounded by silica gel bound to matrix of aluminium and calcium carboy late some water is present in matrix fluoride ions are also released into the matrix during the setting reaction |
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Is GIC cement hydrated?
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yes, water can be gained and lost from the cement
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Fluoride is released from ______ into the oral environment and can be absorbed from the oral _______ and re-released.
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matrix, environment
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What is RMGIC?
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resin modified GIC
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what is composition of RMGIC?
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powder and liquid component like GIC and a hydrophilic resin HEMA
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Explain setting of RMGIC
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setting reaction initially involves curing of the resin followed by a slower acid-base setting
this gives: slight increase in working time greater control over setting time some increase in strength decreased susceptibility to initial moisture uptake decreased susceptibility to desiccation |
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What are examples of setting RMGIC?
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light curing
autocure light cure and auto cure **most are duel and use light to hurry along** |
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as the resin component increases the acid-base contribution??
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decreases
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What characteristics can be lost if too much resin is added to a RMGIC?
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fluoride release
chemical bond |
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What is in a composite resin matrix?
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UDMA
Bis-GMA- bisphenol a Diglycidylether methacrylate |
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What are the glass filler particles of a comp resin?
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silica and quartz
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What binds particles to resin?
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silane coupling agent
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What does the setting reaction (polymerisation) involve for comp resin?
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linking of small chain molecules (monomers) to form large chain polymers
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What does set resin consist of?
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glass particles
bound in resin matrix |
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What are the key points with resin polymerisation?
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there is no chemical bond with tooth substance
there is no significant fluoride release the resin contracts on setting |
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What are some modification of comp resin to alter properties?
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filler variations
aesthetics strength and hardness handling and manipulation flowable vs packable |
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What is a composer?
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polyacid modified comp resin
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what is the compostiton of a composer?
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resin matrix substituted--> hydophilic resin matrix to allow water uptake for an acid base reaction. e.g. UDMA or activator/initiator
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What are the glass filler particles of a compomer similar too?
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a GIC, silica, alumina and fluoride salts
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Why is there no chemical bond to tooth with composers?
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to react with glass there is a delayed reaction with water absorption. Because of this some fluoride is realeased but not able to form chemical bond
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What are aesthetics of compomers compared with?
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comp resin
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explain the strength and wear for a compomer
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greater than RMGIC but less than comp resin
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explain a Giomer
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resin based with pre-reacted GI particles added,
fluorosilicate glass particles reacted with polyacrylic acid prior to being incorporated into the resin * attempt to achieve properties of comp resin with fluoride, characteristics similar to composer* |
