1. C - Bonding Theory

Question 1

Describe the Total Etch (4th Gen) systems.

Answer 1

• 3 - step bonding adhesives
  
  • Etch
  • Primer
  • Bonding resin
• Most sensitive technique
• Gold Standard
• Highest bonding values

Question 2

Which bonding adhesive system is the gold standard and has the highest bonding values?

Answer 2

Total Etch Systems - 3-Step Bonding Adhesives

(4th Generation Adhesives)

All-bond 2, Scotchbond MP, Optibond FL

Question 3

Describe the 5th Generation (2-step) adhesives.

Answer 3

• 2-step adhesives
• Etch
• Prime/Bonding resin (single bottle)
• Enamel is poorly etched

Question 4

Which 5th generation adhesive has a neutral pH?

Answer 4

Prime & Bond

Question 5

Describe the 6th generation bonding system.

Answer 5

• 2 steps
• Etch & Prime (H2O)
• Bonding resin
• Self-etch

Question 6

What are the names of the 6th gen adhesives?

Answer 6

• Clearfil SE Bond
• Liner Bond II

Question 7

Describe the Self-Etch systems.

Answer 7

• “All-in-one” adhesives
• Etch/Primer/Bond

Question 8

What are the main pro’s and con’s of the self-etch systems? (single step)

Answer 8

• Pro’s
  
  • pH can be lowered to etch uncut enamel
  • Lower sensitivity
  • Less technique sensitive
• Con’s
  
  • pH is still limited, smear layer retained
  • Water entrapment in hybrid layer

Question 9

What type of adhesion system has the “true bonding”?

Answer 9

Glass Ionomers

Question 10

Why don’t you use glass ionomers as a luting agent for all ceramic restorations?

Answer 10

• Water expansion

Question 11

What are the steps in forming good adhesion?

Answer 11

1. Clean adherend
2. Good wetting
3. Intimate adaptation
4. Bonding
5. Good curing

Question 12

What is the performance factor that is the biggest variable for success?

Answer 12

Operator - technical ability, age, eyesight, etc

Question 13

What are the 5 performance factors?

Answer 13

1. Operator
2. Design
3. Materials
4. Intraoral Location
5. Patient

Question 14

What is the function of dentin bonding primers?

Answer 14

• Displace water and allows monomers to penetrate dentinal collagen matrix
• Alcohol or acetone evaporates and removes water
• Promotes infiltration into collagen

Question 15

What does dried enamel do for bonding strength?

Answer 15

• It increases the surface energy allowing hydrophobic resin to impregnate the rods with deep resin tags

Question 16

What is the majority of our “dentin bonding”?

Answer 16

Intertubular dentin

Question 17

What are the factors affecting dentin adhesion?

Answer 17

• Dentinal wetness
• Smear layer
• Isolation

Question 18

Can you rinse away the smear layer?

Answer 18

No, but etch and rinse will, self-etch maintains it

Question 19

The smear layer may reduce dentin permeability by as much as ____?

Answer 19

86%

Question 20

What creates a thick smear layer?

Answer 20

Diamond burs

Question 21

Where do the “water trees” form?

Answer 21

Under the hybrid layer

Question 22

What is the C-factor?

Answer 22

• Ratio of bonded resin surface/un-bonded resin surface
• Higher C factor = more shrinkage & strain

Question 23

What is the elastic bonding concept? (tensile buffering)

Answer 23

• When composite is cured and shrinks
• A more elastic bonding resin layer allows the resin interface to stretch
• This preserves the hydrbid layer

Filler = more elastic

Question 24

Describe the LEGO system.

Answer 24

• Liner
• Etch
• Gluma
• Optibond Solo Plus

Question 25

Most composites are under-cured, what are 2 measures to make sure this doesn’t happen?

Answer 25

1. Correct placement of light
2. Use a finger rest

Question 26

What’s wrong with curing composites with the laser system?

Answer 26

• Excessive polymerization strain and shrinkage
• Heat
• Composite crazing & shrinkage = sensitivity

Question 27

Which light systems have narrow emission spectrums?

Answer 27

• Laser systems
• LED systems

Question 28

How can you reduce internal stresses?

Answer 28

• Soft-start polymerization
• Incremental additions with C-factor
• Stress breaking liner