glass ionomer cement Flashcards
properties
1) self adhesive
2) function
3) esthetics
self-adhesive
- ionic bond to tooth
- no adhesive needed
- tolerant of moisture
- bond improves over time
- CTE similar to that of tooth structure
function
1) good caries resistant
2) poor wear resistance
3) fluoride release and recharge
esthetics
1) opaque
2) poor polish
3) some shade selection
4) esthetics vary with type
5) loss of contour over time
uses
1) direct restorative
- endo treatment
- caries control
2) root caries
- high caries risk
- difficult isolation
- many are class V
3) luting cement
- Gold, PFM, zirconia
4) cavity liner
- seals dentinal tubules, indirect pulp cap
brand names
1) conventional (GI)
- fuji IX
2) resin modifies (RMGI)
- fuji II LC
-fuji triage (temp restoration)
3) cavity liners
- activa (resin modified)
4) luting cements
- fuji CEM (Resin modified)
powder + liquid
1) fluoro-alumino-silicate glass
- SiO2
- Al3+
- Ca2+
- F-
2) mixed with liquid
- polycarboxylic acids will dissolve the superficial layers of powder
- Al3+, Ca2+. and F- pulled into solution
3) Al3+ and Ca2+ form ionic cross links between the carboxylate groups
- polyalkenoate salt
4) unreacted glass inhibits crack formation
bonding to tooth structure
1) carboxylate group ionically bond to calcium in hydroxyapatite
2) no polymerization shrinkage
3) low shear bond strength
4) fluoride and water move freely through matrix, exchanging with environment
chemically fused layer
1) the layer bonded between enamel and the GI
fluoride release
1) rapid, early release from matrix
2) slow, long term release
- does not take part in matrix formation
- does not result in loss of physical properties
- amount of release similar for both conventional and RMGI
high early release
1) 1-2 days
2) 50 ug/cm^2/d
3) sustained low levels (1 ug)
fluoride reservoirs
1) rechargeable
2) uptake and re-release
- topical fluorides (Naf)
3) only fraction of initial F level
chemistry of resin modified GI
1) powder
- its the same fluoro-alumino silicate glass with a catalyst
2) liquid
- polycarboxylic acid
- hydrophilic monomers (HEMA)
- hydrophobic monomers (bis-GMA)
- initiator
resin modified GI acid
1) acid base reaction
- slower than conventional GI
- matures over time
- responsible for bond to tooth
2) resin polymerization
- light, chemical, or dual cure
- allows finishing and polish
- some shrinkage
know table of comp vs GI vs RMGI
:(
contraindications
1) stress bearing areas in permanent teeth
2) class I, II, and IV
comparative bonding process
1) GI
- tooth conditioned with 10% poly acrylic acid
- chemical bond (ionic exchange)
2) composite
- 37% phosphoric acid etch
- primer and bonding agents to micromechanically bond enamel and dentin
comaprative fluoride release
1) GI
- acid base reaction carries fluoride into tooth
- most in first 2 days
- rechargeable
- chemically fuse layer
- zone of inhibition
2) composite
- no acid base reaction
- no ion exchange
- no fluoride
- hybrid layer
preparation
1) pathology driven
- caries, noncarious lesion
2) mechanical retention not needed
3) 90 degree cavosurface
surface conditioning
1) polyacrylic acid conditioner
2) removes smear layer for letter ionic bonding to calcium
3) NO phosphoric acid etch (no hybrid layer)
4) surface damp
inside a GI capsule
1) glass powder
2) liquid
3) plunger
- click it to break the diaphragm
- mixing is “priming”
triturate
1) 10 seconds
2) 8 seconds is better for slower setting
capsule applier
1) inert into capsule applier
2) click twice to prime capsule
- second click
mixing
1) triturate
2) spatulated or automixing for liner
