GIC

Question 1

What reaction is GIC made from?

Answer 1

acid-phase reaction with 3 phases

Question 2

What are the 3 phases of the acid-base reaction?

Answer 2

Dissolution (acidic attack of glass surface)

Gelation (early cross-linking by Ca++)

Hardening (substitution of Ca++ by Al+++)

gives salt and water

Question 3

What makes GIC very soluble?

Answer 3

All the COOH groups together in the long chain polyacid

Question 4

What are the properties of GIC?

Answer 4

• Adhesion to mineralised tooth tissues
• F- release and associated protection against caries
• Antibacterial activity?
• Set without exotherm and no shrinkage.
• Biocompatible
• May be radio-opaque.
• BUT relatively poor aesthetics, poor wear resistance, brittle, no command set, technique sensitive…

Question 5

Why can GIC adhere to the tooth?

Answer 5

GIC has acid degraded particles (calcium) - form salt bridges with the calcium in the tooth tissue

Question 6

What are the clinical uses for GICs?

Answer 6

• Restoration of deciduous (primary) teeth.
• Class V restorations in permanent teeth.
• Erosion/abrasion lesions.
• Have been used as fissure sealants.
• Atraumatic restorative treatment(ART)
• Luting cements.
• Cavity bases.

Question 7

What are the contra-indications for GIC?

Answer 7

Highly loaded sites or incisal edge

or where aesthetics are important

Question 8

What is a glass Carbomer?

Answer 8

Documented as a heat cured material and marketed as a potential alternative to GICs with similar indications of use

• stronger and smoother finish due to finer filler size, less soluble and has better translucency and possible fluoride release

Question 9

what mechanisms may make fluoride antibacterial?

Answer 9

effects on metabolism via enolase inhibition and/or metabolic toxicity

Question 10

When may fluoride not be antibacterial?

Answer 10

when microorganisms are protected within a biofilm.

Question 11

How does fluoride ion exchange work?

Answer 11

• interaction with HA of enamel and dentine
• F ions able to substitute for OH groups in crystal structure to generate FA
• FA very resistant to demineralisation

Question 12

Which hybrid biomaterials are treated as a GIC?

Answer 12

GIC
Cermet glass PVP carbomer
RM- GIC

Question 13

Which hybrid biomaterials are treated as a composite resin?

Answer 13

GIomer
Compomer
Ormocer
Composite resin

Question 14

How is a RM-GIC different to GIC?

Answer 14

Like a Glass-ionomer but with the addition of a water miscible monomer hydroxyethylmethacrylate (HEMA) and a photoinitiator

sets with both an acid-base reaction and photo-polymerisation

shares GIC chemical bond to untreated dentine

Question 15

How does Dyract AP release fluoride?

Answer 15

Needs to absorb water before it can release fluoride