Class 2 Restorations

Question 1

A Class II amalgam preparation has an open side on the…

Answer 1

interproximal.

Question 2

What is used to hold the amalgam in the interproximal area during a class II restoration?

Answer 2

matrix band with a tofflemire retainer and a wooden wedge

Question 3

What are the functions of a good matrix band?

Answer 3

1. Has enough rigidity to resist too much deformation by packing forces or wedging, but is slightly burnishable and displacable
2. Assists in establishing proper anatomical contour.
3. Must prevent excess amalgam from being expressed at the gingival margin as much as possible, so as not to get a gingival overhang that will trap plaque and irritate the gingivae.
4. Must be convenient to install.
5. Must be easy to remove and allow for removal without breaking a partially set amalgam.

Question 4

What are the parts of the tofflemire retainer?

Answer 4

Question 5

What type of tofflemire band do we use in lab?

Answer 5

adult band - box or normal depth gingivally

Question 6

What are the steps to inserting band into the tofflemire retainer?

Answer 6

1. Turn the inner nut counterclockwise until slot vice is about ¼ inch from the guide channels.
2. Hold inner nut and turn the outer nut counterclockwise until the pointed end of the spindle is free of the slot in the slot vice.
3. Double the band back on itself, forming a loop.
4. Insert into the slot vice, and direct it through one of the three guide
   channels. Tighten spindle.

Question 7

Wider Opening in the Loop is Toward the _______ of the Tooth

Answer 7

Occlusal

Question 8

Slot in Slot Vice is Toward the _______ of the Tooth

Answer 8

Gingival

Question 9

What are the ways to insert the tofflemire band?

Answer 9

1. Retainer on the buccal side; band emerges from one of the side guide channels (most common)
2. Retainer on the lingual side; must use a contra-angle retainer
3. Band emerges through the middle channel and straight out the end of the retainer; retainer is on the lingual of the tooth

Question 10

If the band won’t go far enough apically to close the gingival margin in a deep box, use a band that has an…

Answer 10

“apron”
(clinic only)

Question 11

How do you get ride of the open margin between the band and the tooth?

Answer 11

wooden wedge

Question 12

When would you use a double wedge (one from lingual and one from buccal)?

Answer 12

in the event of an especially wide interproximal space and a gingivally deep box

Question 13

When would you use the stacking method to double wedge?

Answer 13

gingival recession and a proximal
box of moderate depth

Question 14

What are the steps for obtaining a good contact?

Answer 14

*Loosen the band a quarter turn after wedging
*Burnish the band against the proximal surface of the adjacent tooth.
*Scrape with an explorer along the tooth-metal interface at the gingival margin to remove any tissue or debris in this area.
*Pack amalgam hard against the matrix band in the contact area.

Question 15

Occlusal edge of marginal ridge slightly _________, creating slightly open occlusal embrasure on an amalgam class II restoration.

Answer 15

rounded

Question 16

What are the additional steps you need for restoring a class II with composite versus amalgam?

Answer 16

Etch (and rinse), Bond Agent placement (gentle dry, light cure), composite placed incrementally, light cure each increment

Question 17

Why is composite harder to establish contact in a class II restoration than amalgam?

Answer 17

• Composite does not displace the matrix band like amalgam
• Shrinkage occurs as you light cure
• Different type of matrix may help counteract this issue

Question 18

What are the steps for complete etch?

Answer 18

◦ Place etch on enamel first, followed by dentin
◦ ETCH ENAMEL 20-30 SECONDS
◦ ETCH DENTIN 15-20 SECONDS
◦ Rinse and gently air dry
◦ Typically only done with total-etch and universal bond agents

Question 19

What are the steps for selective etch?

Answer 19

◦ Etch enamel only
◦ 20-30 seconds
◦ Rinse and air dry
◦ Can only be done with certain bond agents
◦ Universal (what we use in clinic and lab) and Self-etch types

Question 20

How should you use etch?

Answer 20

Rinse and dry thoroughly.
◦ Be sure to dry on both sides of the matrix band and around the proximating teeth. Check for the whitish etched enamel surface. Re-apply the etchant if there is not clear evidence of etched enamel.
◦ It may be appropriate to re-etch for 10 seconds if the enamel or dentin is contaminated with saliva then wash, dry apply bonding agent, cure and continue.

Question 21

What is important to not desiccate while etching?

Answer 21

the dentin
- results in collapse of collagen layer and reduced bond strengths

Question 22

What is the oxygen inhibited layer? (good test question)

Answer 22

The sticky uncured layer left on the surface
- Oxygen in air interferes with polymerization on surface of composite

Question 23

What does the oxygen inhibited layer do for the next layer?

Answer 23

facilitiates bonding to the next layer added

Question 24

What is the most important composite layer to make sure is cured when filling a class II composite restoration?

Answer 24

first increment at the gingival wall

Question 25

What helps you establish interproximal contact on a composite class II restoration?

Answer 25

• Press the matrix band firmly against the marginal ridge of the proximating tooth with the side of a metal condenser while curing the initial increments.
• Palodent Plus shapes this for you

Question 26

What instrument should you use to form the final anatomy of a class II composite restoration?

Answer 26

plastic instrument

Question 27

What should you remove before the final cure during a class II composite restoration?

Answer 27

remove the matrix

Question 28

What are new things to consider with the composite class II restoration?

Answer 28

interproximal contacts
voids
light
polymerization stress

Question 29

How can voids be created?

Answer 29

• Composite can stick to an instrument and upon pulling back, a void is created
• When injecting the material, lifting the syringe may cause tug back and a void is created

Question 30

What does finishing and polishing class II composite restorations do?

Answer 30

◦ Removes the oxygen inhibited layer
◦ Establishes anatomy/final shape
◦ Ensures a smooth surface
◦ EXTREMELY IMPORTANT IN COMPOSITE