Final Exam: Glass Ionomers Flashcards
What are some advantages to glass ionomers:
1) What kind of adhesion to tooth structure?
2) What does it release?
3) The coefficient of thermal expansion (CTE) is similar to what?
4) What kind of compatibility?
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- They are non-load-bearing like which restoration class?
- Where would glass ionomers be useful ?
1) Inherent (chemical) adhesion to tooth structure
2) It releases FLUORIDE
3) CTE is similar to tooth structure
4) Biocompatible
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- Non-load-bearing like Class V/III (Not class I, II, IV)
- Good for pediatrics and mission trips – can set up on their own.
What are the two basic glass ionomer types and provide reaction types/cure under these two basic glass ionomer types?
1) Conventional GI:
- Traditional acid-base reaction
2) Resin-modified (RMGI):
- Acid-base reaction
- Light and/or chemical cure (Resin)
- Free-radical polymerization
Give the three phases in the setting reaction of conventional glass ionomers:
1) Ion-Leaching Phase (acid attacks)
2) Hydrogel (midway, soft)
3) Polysalt-Gelt Phase (final, sensitive to dehydration)
In the Ion-Leaching phase of conventional glass ionomers (setting reaction), what gets formed?
- Is this formation native of the matrix?
- Do the physical properties get affected by F depletion?
Ion-Leaching Phase (acid attack on glass):
- NaF is formed
- NOT native of matrix
- Physical properties is NOT affected by depletion of F.
In the Polysalt-Gel Phase of conventional glass ionomers (setting reaction), what is it sensitive to?
– Is the maturation of the matrix slow or fast? How long?
Polysalt-Gel Phase (final, sensitive to dehydration):
- Later stage susceptible to dehydration
- Maturation may require 6 mo – 1 yr
list the three setting reaction of Resin-modified glass ionomer (RMGI):
- Traditional glass-ionomer acid-base reaction
- Free-radical polymerization
- Cross-linked resin-reinforced matrix
In traditional glass-ionomer acid-base reaction of RMGI, does this reaction proceed fast or slow?
Proceeds more slowly
In the Free-radical polymerization setting reaction of RDMI, what is this reaction similar to?
– Through which two ways?
- Similar to composites.
- Light initiated
- Chemical
- Similar to composites.
Fluoride release:
- What kind of release is it from the matrix. Give time frame as well.
- – What happens to this fluoride release after it gets released from the matrix?
- -What kind of release is it from the particle.
- RAPID EARLY release. Occurs in the 1st two days. (INITIAL BURST)
- SUSTAINED LOW LEVELS: Then maintains a low level through the life of restoration.
- SLOW, LONG term release from particle.
During the process of fluoride release, does the fluoride take part in matrix formation?
– Does it result in loss of physical properties?
Fluoride release does NOT take part in matrix formation.
Fluoride release does NOT result in loss of physical properties.
Fluoride release:
What’s the difference in the amount of fluoride release in conventional and RMGI
– NONE. Amount of release similar for both conventional and RMGI.
Fluoride release:
- What are the two processes in fluoride reservoirs
- What type of fluoridation falls under this type of fluoride reservoirs
- How much of the fluoride gets re-released?
- Uptake and re-release
- Topical fluorides - Only a fraction of initial F level
RMGI Luting Cements
RMGI luting cements have one unique property that causes it to be a contraindication for a certain material during restoration work.
1) What is this unique property?
2) What type of restoration (certain material), would RMGI Luting cements not work on?
3) What would happen if we used RMGI Luting cements on these types of restoration.
1) Hydroscopic Expansion
2) Non-reinforced all-ceramic restorations
3) this luting cement expands with it sets and will fracture crowns (those that are made with all-ceramic restorations)
Of all the materials we’ve gone over in class, which one releases the most fluoride?
- Which one releases the least?
- Pure glass ionomer releases the most fluoride
- Composite releases the least.
