GIC restorations

Question 1

What are the key attributes of glass ionomers?

Answer 1

see slides

Question 2

What are the types of GIC restorations?

Answer 2

True GIC - auto-cure (eg. equia forte)

Resin-modified GIC which is light cured

Question 3

What are the types of true glass ionomers?

Answer 3

Stronger restorative materials

Weaker temporary or surface protection materials (eg GC FUJI 7)

Question 4

What are the types of resin-modified glass ionomers?

Answer 4

see slides

Question 5

How does GIC work?

Answer 5

Acid base reaction results in enamel and dentine “melting” into the restoration. This creates a bond because both ions from the composite and the ions of the enamel are mixed and hardened.

Question 6

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Answer 6

Chemical fusion to enamel and dentin

An ongoing water-based ion-leakage over time

Prevents microleakage

Question 7

Some important GIC clinical tips to remember:

Answer 7

Don’t over-dry the cut dentine (GIC is water based) Use a cotton pledget or very light air drying to dry the cavity

Don’t allow any saliva to contaminate dentine surface

After GIC set cover with an unfilled resin (not a dentine binding agent) and light cure

Question 8

What are the indications for using GIC?

Answer 8

Fissure seals in young patients

Small occlusal permanent restorations

Class 5 restorations outside the aesthetic zone and some class 3s

Temporary caries control restorations

Temporary restorations after cusp fractures

As luting cements

GIC has inadequate strength for class 2 permanent fillings

Never use for a class 1 under load

Question 9

What are the indications for using GIC?

Answer 9

Proximal white spot lesions

Fissure seals in young patients

Small occlusal permanent restorations

Class 5 restorations outside the aesthetic zone and some class 3s

Temporary caries control restorations

Temporary restorations after cusp fractures

As luting cements

GIC has inadequate strength for class 2 permanent fillings

Never use for a class 1 under load (fine for small occlusal only)

Question 10

How is a glass ionomer fissure seal administered?

Answer 10

Clean out fissure with probe

Fissure conditioning with 10% polyacrylic acid

Wash and air-dry fissure gently

Syringe in viscous true GIC, rub over fissure with a gloved finger covered with unfilled resin/light cure

Question 11

How is … treated?

Answer 11

Composite bonding can’t bond to demineralized enamel - Only GIC can

Remineralize with good plaque hygiene and fluoride application

Question 12

How is lost tooth structure replaced?

Answer 12

Replace lost tooth structure with GIC only roughen dentine with a slow bur, condition with polyacrylic acid/rinse/inject GC equia forte.

Question 13

How is equia forte treated?

Answer 13

Water spray is necessary after it has hardened and needs trimming.

Normal chemical set true GIC

After set needs moisture protection

Question 14

Why does FUJI VII release the most fluoride?

Answer 14

Weak material with high liquid to powder ratio

Question 15

problems with GIC:

Answer 15

Another problem with GIC’s is that they dissolve in highly oral acidic environments

GIC acts as a sacrificial anode

Question 16

What is the main limitation of composite and how is GIC better for this purpose?

Answer 16

Composite can fail and GIC is less likely to fail due to bonding microleakage.

Question 17

How strong is the bond between composite and dentine?

Answer 17

Resin dentine bonds degrade over time due to presence of Matrix Metalloproteinases

Question 18

How can most reliable bonding be created with composite material?

Answer 18

Bonding the composite to enamel rather than dentine

Question 19

What are the limitations of (composite)?

Answer 19

Reduces composite volume - polymerization shrinkage

Reduces microleakage risk near the pulp in deep composite restorations

and 2 more points

Question 20

What is the best indication for sandwich restorations?

Answer 20

Best indication for a sanwich restoration is deep class 1 caries

Question 21

What are the benefits of using …?

Answer 21

Poor abrasion resistance

Low compressive strength

Low fracture resistance

Susceptible to dehydration

The physical and aesthetic properties are inferior

Question 22

What is GIC used for in sandwich technique?

Answer 22

A thick layer of GIC acts as a dentine substitute to ensure no microleakage near the pulp

Question 23

How much GIC should be used in sandwich technique?

Answer 23

> 2mm or it will fail.

Question 24

What are the types of sandwich restorations?

Answer 24

Open and closed sandwich

If we have a lot of tooth missing you want glass ionomer near the pulp

Question 25

What are the problems with open sandwich technique restorations?

Answer 25

GIC dissolution

Difficult to bond a true GIC to a composite resin

Question 26

What should be considered before GIC use?

Answer 26

In high caries risk GIC is better than amalgam/composite

Never put open sandwich glass at contact point.

Question 27

How is composite bound to GIC?

Answer 27

It is difficult to bond composite to equia forte. This is done with scotch bond or RIVA bond LC. Scotch bond is better due to use of it already for normal composite restorations.

Question 28

Should GIC be etched?

Answer 28

Don’t etch the GIC only etch the enamel

Question 29

How should GIC be used?

Answer 29

Before curing shape marginal ridge and contours

Carve from midpoint of marginal ridge in both directions

Question 30

Why use a GIC sandwich restoration?

Answer 30

Laminating composite over GIC removes the wear and strength problems of an occlusal GIC restoration

Reduces volume of posterior composite = less resin polymerization shrinkage and stress

GIC creates a true chemical-ionic bond to tooth structure with a long-term seal to dentine/tooth

GIC is a biomimetic and remineralized soft affected caries

GIC has similar coefficient of thermal expansion to dentine

Long-term fluoride release and re-charge

Indicated for deep posterior Class I and
Class II - Class II floor of box, with no enamel margin