1. Glass Ionomers

Question 1

7. What are the four advantages of using glass ionomers?

Answer 1

1. Inherent (chemical) adhesion to tooth structure
2. Fluoride release
3. Coefficient of thermal expansion (CTE) similar to tooth structure
4. Biocompatible

Question 2

12. What does RMGI stand for?

Answer 2

Resin-modified glass ionomer

Question 3

12. What two types of chemical reactions are used in the curing process of RMGI’s (hence the reference to them sometimes as “dual cured glass ionomers”)?

Answer 3

1. Acid-base reaction

2. Light and/or chemical cure

Question 4

16. What are the three phases that the conventional glass ionomer restorations will undergo as they settle over time?

Answer 4

1. Ion-leaching phase
2. Hydrogel
3. Polysalt-Gel phase

Question 5

17. Ion-leaching phase of conventional Glass Ionomers
    - What chemical is formed that is not native of the matrix and its depletion (leaching) does not affect the physical properties of the restoration?

Answer 5

NaF

Question 6

24. What setting reaction step of RMGI’s is similar to a setting reaction step found in traditional glass ionomers?
    - What is one difference in this step?

Answer 6

Traditional glass-ionomer acid-base reaction

- RMGI’s proceeds more slowly though

Question 7

28. What are the two phases of fluoride release from glass ionomer restorations?

Answer 7

1. Rapid early release from matrix over 1 to 2 days

2. Slow, long term release from particle

Question 8

28. Does the release of fluoride from glass ionomer restorations affect the physical properties of the restoration? Why?

Answer 8

No, release of fluoride does not affect physical properties

- This is because fluoride does not take part in matrix formation

Question 9

29. How do glass ionomer restorations act as fluoride reservoirs?

Answer 9

They uptake and re-release fluoride, but only up to a fraction of the initial fluoride level.
- Example of re-uptake is topical fluoride

Question 10

34. Glass Ionomers - RMGI - Compomers - Composites
    - To which end does strength increase?
    - To which end does polishability increase?
    - To which end does fluoride release increase?

Answer 10

Strength to right side
Polishability to right side
Fluoride release to left side

Question 11

34. Organize the following four restorative materials based on their strength, from weakest to strongest:
    - Compomers, composites, glass ionomers, and RMGI’s

Answer 11

1. Glass ionomers (weakest)
2. RMGI’s
3. Compomers
4. Composites (strongest

Question 12

34. Organize the following four restorative materials based on their polishability, from worst to best:
    - Compomers, composites, glass ionomers, and RMGI’s

Answer 12

1. Glass ionomers (worst)
2. RMGI’s
3. Compomers
4. Composites (best)

Question 13

34. Organize the following four restorative materials based on their ability to release fluoride, from worst to best:
    - Compomers, composites, glass ionomers, and RMGI’s

Answer 13

1. Composites (worst)
2. Compomers
3. RMGI’s
4. Glass ionomers (best)

Question 14

40. What is the one contraindication for usage of RMGI luting cements? Why?

Answer 14

Non-reinforced all-ceramic restorations

- The expansion of the luting cements will break the ceramic crown

Question 15

24. What are the two setting reaction steps for RMGI’s?

Answer 15

1. Traditional glass-ionomer acid-base reaction

2. Free-radical polmerization (light intiated step, like composite)