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58 Cards in this Set
- Front
- Back
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Uses of GIC
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luting cement
ortho adhesive preventative sealant lining + base limited restorative uses |
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Chemical reaction of GIC & components
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Acid base reaction:
polyalkanoic acid + fluoride |
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Components of fluoroaluminosilicate glass.
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34% Calcium Fluoride
30% silica 16% alumina 10% aluminium phosphate 5% cryolite |
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Liquid components of GIC
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50% polyalkanoic acid
40% distilled water tartaric acid (sharpen setting time) |
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Fluoride action in GIC
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GI can release F over time
moves freely in & out of GI F reservoir for tooth |
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Setting reaction of GIC & three steps.
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Autocure:
1. dissolution (instant-mins): H ions from acid attack glass & Ca, Sr, Al, F released 2. precipitation (up to 24hrs): Ca then Al chains 3. hydration (months): cross links cont. + more rigid |
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What does tartaric acid do?
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Retain working time & sharpen setting time
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How does GIC adhere to the tooth?
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Chemical bond: carboxyl group from polyacid bond to Ca ions in enamel and dentine
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Interdiffusion Zone
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Ca (from enamel) & phosphate intermix & precipitate
Becomes stronger & more resistant than tooth or GIC |
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What is the Ion Exchange Layer?
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IDZ + chemical bond that occurs (Ca + carboxyl group)
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Components of Dentine conditioner
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10% polyacrylic acid
90% distilled water |
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Purpose of Dentine conditioner. How is it used?
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enhance bond between GIC and tooth
remove biofilm, smear layer, saliva, blood proteins doesn't open dentinal tubules or demin. dentine 20s application, wash, dry |
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Components of cavity conditioner
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20% polyacrylic acid
77% distilled water 3% aluminium chloride hydrate |
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Purpose of cavity conditioner. How is it used?
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seal dentinal tubules (elim. sensitivity )
optimal chemical adhesion 10s application, rinse, dry |
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Main component of etchant
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phosphoric acid
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Purpose of etchant
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open dentinal tubules
demin. inter/peritubular dentine |
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Solubility of GIC
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High is slow set autocure if not protected for the first 24 hours.
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Dimension change of GIC
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3% contract in Fuji V when set
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Does RMGIC have less dimension change/contraction? Why?
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Yes.
Molecular mechanisms of polymerisation of resin |
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How is the contraction of GIC negated?
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Overtime absorbs water then expands to negate shrinkage
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Is GIC susceptible to fracture?
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Yes. Susceptible to brittle fracture.
Lacks rigidity of CR or amalgam |
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Where should you avoid using GIC?
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Areas with great occlusal bearing load.
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Is GIC sensitive to acid wear?
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Yes
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What are the aesthetic advantages of GIC?
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Great colour range and translucency
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How does GIC appear radio-opaque?
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Addition of Ba, Sr, Lanthanum
(usu. more opaque than enamel) |
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What is the solid component of RMGIC?
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fluoroaluminosilicate glass
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What are the liquid components of RMGIC?
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30-35% HEMA
20-30% polyacrylic acid 20-30% distilled water <10% UDMA <1% camphoroquinone |
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What is the setting reaction of RMGIC?
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Light cure
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What are the 4 main advantages of RMGIC?
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1. prolonged working time
2. rapid set (light cure) 3. immediate resistance to water uptake 4. can be polished immediately |
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What are the two chemical reactions of RMGIC?
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1. acid/base
2. photochemical polymerisation |
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What is a commercial brand/name of RMGIC?
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Fuji VII Pink
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What is the purpose of ferric oxide in RMGIC?
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pink absorbs heat easily
cured with halogen light (LED not enough heat) |
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What is the main advantage of RMGIC?
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Highly bactericidal due to high F release
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3 main uses of RMGIC
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1. fissure protection
2. root surface protection 3. lining |
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How does RMGIC set?
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TRICURE:
1. acid/base: polyacrylic acid + FASG 2. photo-initiated polymerisation of HEMA 3. redox reaction: chem. catalyst for polymerisation of HEMA |
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Purpose of camphoroquinone
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Allows for photo-initiated polymerisation of HEMA
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Describe fluoride release of RMGIC
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Initial F release quite high after application
declines rapidly in first week stabilises to low but constant level over 2-3 months |
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What is the affect of applying topical fluoride to RMGIC?
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F levels can be 'recharged'
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3 advantage of Fluoride release in GIC
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Remin tooth
Inhibition of plaque formation Reduction of recurrent caries |
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Fuji IX
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Conventional GIC
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3 uses of Fuji IX
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Usu. for primary teeth
Some class III or V in perm. teeth Direct pulp capping (BASE) |
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GC Fuji II LC capsule
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RMGIC
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GC Fuji IX Extra
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Conventional GIC
higher F release better translucency lower compressive strength |
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GI Lining (Fuji Bond LC)
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RMGIC, hand mixed
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Purpose of GI Lining
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seal dentinal tubules under CR and amalgam
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Fuji VII
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fine FASG filler
Sr for radio-opacity |
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Fuji VII White
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self cure conv. GIC
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Fuji VII Pink
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optional command set with halogen light
reminds patients of temporary nature of sealant indicates clear margins |
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How is micro-leakage prevented?
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Ion exchange layer adhesion prevents microleakage
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What if rubber dam isolation isn't possible? E.g. Mouth breathers.
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GIC can be used with cotton rolls & Garmer's clamp
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5 disadvantages of GIC
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1. management of water loss/gain during setting crucial
2. prolong setting: auto-cure 3. setting contraction 4. solubility & disintegration 5. wear physical property (fracture, low abrasion res.) |
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For how long do you cure GIC?
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20s
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What can you use to polish GIC?
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diamond bur
silicone tip polishing strip (Fuji coat) |
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When do you polish GIC?
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Next appointment
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4 reasons why moisture protection is important for GIC
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1. ensures effective 'wetting' for strong adhesion
2. GIC susceptible to water uptake/loss during set 3. weakening of matrix = early failure |
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What can be applied to GIC to prevent water/saliva contamination?
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Cocoa Butter
(Fuji Coat LC or G Coat Plus. with 10s cure) |
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Purpose of GC Fuji Coat LC
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prevent dehydration
protection against humidity smooth glossy finish |
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What are the components of GC Fuji Coat LC?
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Methylmethacrylate
dimethylacrylate ester urathane acrylate |
