Week 8- Cementing and Bonding

Question 1

What are advantages of digital dentistry?

Answer 1

• Better fitting restos
• More diversity
• Increased speed in resto techniques
• More time efficient solutions at lower cost
• More predictable outcomes

Question 2

Should you bond or cement crowns if there is adequate retention from prep?

Answer 2

Cement (rely x unicem)

Question 3

What is the potential issue with 3Shape TRIOS MOVE +?

Answer 3

May not take into consideration occlusal factors (lengthening teeth might be issue in protrusion)

Question 4

What is the curing method of rely x unicem and how long does it take to set?

Answer 4

Dual cured. If not light cured, takes 4 minutes to set.

Question 5

What would be required for this tooth before placing crown?

Answer 5

Crown lengthening (electrosurgery or laser to remove gingival tissue to get more length of crown)

Question 6

Why does zirconia need to be cleaned after try in?

Answer 6

Phosphate and calcium ions from saliva contaminate zirconia fitting surface

Question 7

What is used to clean zirconia?

Answer 7

Ivoclean (removed calcium and phosphate). Paint on and wash off

Question 8

Why does lithium disilicate glass not need to be cleaned after saliva contamination?

Answer 8

It does not attract calcium and phosphate ions

Question 9

What should be placed on lab form for zirconia crown?

Answer 9

Aluminium oxide blast fitting surface (micromechanical retention)

Question 10

How is ivoclean used?

Answer 10

1. Wash contaminated fitting surface with water and dry
2. Cover entire bonding surface of resto with layer of ivoclean using an applicator
3. Allow 20 secs for ivoclean to absorb phosphate contaminants.
4. Rinse with water and dry

Question 11

Why doesn’t phosphoric acid gel clean zirconia fitting surface?

Answer 11

Etching gel inhibits bonding agent to form a bond with the surface

Question 12

How is EMAX etched?

Answer 12

HF acid

Question 13

What is used instead of HF acid for etching emax at JCU dental (due to safety concerns)?

Answer 13

Ivoclean and monobond

Question 14

How is ivoclean and monobond used?

Answer 14

1. Paint on fitting surface for about a minute
2. Wash off and dry
3. This silanates emax surface and resin can be bonded.

Question 15

How is SpeedCEM plus used?

Answer 15

1. Following AlO blast and ivoclean, speed cem is applied onto fitting surface.
2. Crown is placed in pts mouth
3. Light cure margins for 5 seconds and remove excess cement

Question 16

What is the bonding mechanism of SpeedCEM?

Answer 16

Adhesive monomer in material is MDP (phosphate and methacrylate)

Question 17

What can be used to cement zirconia crown?

Answer 17

Rely x unicem

SpeedCEM

Question 18

Why should you polish zirconia after adjusting it?

Answer 18

Microcracks develop which must be polished away.

Question 19

How should zirconia crowns be adjusted and polished?

Answer 19

1. Check occlusion with articulating paper
2. Take out of mouth and place on die
3. Use slow speed to adjust
4. Polish with Zircon-Brite
5. Clean and cement in place

Question 20

How should emax be adjusted?

Answer 20

• Bond in place before checking occlusion.
• Emax will crack if adjusted when not bonded.

Question 21

Why does excess cement need to be removed after crown placement?

Answer 21

Avoid plaque formation which can lead to tooth sensitivity and perio disease.

Question 22

How can gingival margins of crowns be finished?

Answer 22

Non-cutting safe end finishing burs that will protect soft tissues.

Question 23

Can GIC be used for cementing veneers and crowns?

Answer 23

No