Composite

Question 1

Used for cervically eroded areas

Answer 1

GIC

Question 2

Used for direct aesthetic restorations

Answer 2

Composite

Question 3

Better aesthetic than GIC

Answer 3

GIC modified resin

Question 4

Composite have fluoride release

Answer 4

False

Question 5

Composers are less aesthetically pleasing and have more wear resistance and fluoride release

Answer 5

False

Question 6

Compomere less aesthetically pleasing and have more wear resistance and fluoride release

Answer 6

False

Question 7

Composite are recommend for classes

Answer 7

3,4,5,1

Question 8

Composite can be classified as

Answer 8

Flowable, packable, laboratory, mircofilled, nanofilled

Question 9

What are composite made of?

Answer 9

Resin, filler particles, silane coupling agent

Question 10

Fine particles
Microfine
Nanofiller sizes

Answer 10

0.2 to 3
0.04
1 to 10

Question 11

What are microhybrid composites?

Answer 11

Microhybrid composites are made by combining fine and microfine fillers. They contain up to 84% filler by weight and 70% by volume, resulting in stronger and more durable properties.

Question 12

Why do microhybrid composites have high filler content?

Answer 12

Microfine fillers fit into the spaces between fine fillers, increasing the total filler concentration to improve strength and performance.

Question 13

What are microfilled composites?

Answer 13

Microfilled composites contain only microfine fillers, with 35% to 50% filler by volume, making the material smoother and easier to handle.

Question 14

Which composite is stronger: microhybrid or microfilled?

Answer 14

Microhybrid composites are stronger because they have a higher filler content compared to microfilled composites.

Question 15

What are the common materials used as fine fillers?

Answer 15

• Quartz
• Lithium aluminum silicate
• Barium glass
• Strontium glass
• Zinc glass
• Ytterbium glass

Question 16

Which fine fillers are radiopaque?

Answer 16

Fine fillers containing barium, strontium, zinc, or ytterbium are radiopaque, making them visible on X-rays

Question 17

Which fine fillers are not radiopaque?

Answer 17

Quartz and lithium aluminum silicate are not radiopaque.

Question 18

What is the purpose of a coupling agent in composites?

Answer 18

The coupling agent creates a strong bond between the inorganic filler particles and the organic resin matrix.

Question 19

What is the most commonly used coupling agent?

Answer 19

Silane

Question 20

What type of compound is silane?

Answer 20

Silane is a bifunctional silicon-organic compound that links inorganic fillers to the organic resin matrix.

Question 21

Why is the coupling agent important?

Answer 21

Without a coupling agent, the fillers and resin wouldn’t bond well, reducing the composite’s strength and durability.

Question 22

What system is commonly used for polymerizing composites?

Answer 22

The visible light-curing system, which uses blue light to start the polymerization process.

Question 23

How does the visible light-curing system work?

Answer 23

• Blue light is absorbed by a diketone.
• The diketone reacts with an organic amine, starting polymerization.
• It takes 20–40 seconds of exposure to fully set the composite.

Question 24

Why doesn’t polymerization occur before blue light exposure in light-curing systems?

Answer 24

The reaction only starts when the blue light activates the diketone, keeping the composite stable until then.

Question 25

What is the self-curing system?

Answer 25

A system that uses: • An organic peroxide initiator • An organic amine accelerator The two chemicals are mixed to start the polymerization process.

Question 26

How long does light-curing take?

Answer 26

Polymerization with blue light usually takes 20–40 seconds.

Question 27

What is the wavelength of the light used for curing composites?

Answer 27

470 nm, which is blue light visible to the human eye.

Question 28

What are the common light sources used for curing composites?

Answer 28

Back: 1. Halogen lights 2. Plasma arc lights 3. Argon lasers 4. Blue light-emitting diodes (LEDS)

Question 29

Which type of composite shrinks less during polymerization, microhybrid or microfilled?

Answer 29

Microhybrid composites shrink less because they have less resin compared to microfilled composites.

Question 30

Why can polymerization shrinkage cause issues with bonding?

Answer 30

Shrinkage can create stress that exceeds the bond strength between the composite and the tooth, leading to marginal leakage (gaps between the composite and the tooth).

Question 31

What are two techniques to reduce the effects of polymerization shrinkage?

Answer 31

1. Layering technique: Polymerize the composite in layers to reduce shrinkage. 2. Indirect method: Create a composite inlay in a lab and bond it with low-viscosity resin cement to reduce shrinkage stress.

Question 32

What is thermal conductivity?

Answer 32

Thermal conductivity is the ability of a material to transfer heat.

Question 33

How does the thermal conductivity of composites compare to metals?

Answer 33

Composites have much lower thermal conductivity than metals and are similar to the conductivity of enamel and dentin.

Question 34

Why is the low thermal conductivity of composites beneficial?

Answer 34

It provides thermal insulation for the dental pulp, protecting it from sudden temperature changes.

Question 35

What is thermal expansion?

Answer 35

Thermal expansion refers to how much a material changes in size when it heats up or cools down.

Question 36

Which composites have higher thermal expansion: microfilled or microhybrid?

Answer 36

Microfilled composites have higher thermal expansion because they have more resin.

Question 37

How does water sorption affect microfilled composites?

Answer 37

Back: Microfilled composites absorb more water, which can lead to discoloration from water-soluble stains.

Question 38

Are microhybrid composites radiopaque?

Answer 38

Yes, most microhybrid composites are radiopaque, meaning they show up on X-rays.

Question 39

Which type of composite has higher compressive strength: microhybrid or microfilled?

Answer 39

Microhybrid composites have higher compressive strength than microfilled composites.

Question 40

does filler affect the compressive strength of composites?

Answer 40

Composites with more filler have higher strength because the filler helps resist forces better.

Question 41

Which composite is better for Class V restorations: microhybrid or microfilled?

Answer 41

Microfilled composites are better for Class V restorations because their lower stiffness reduces stress on the bond between the composite and dentin.

Question 42

What factors affect the depth of cure?

Answer 42

The depth of cure depends on the time of light exposure, the composite product, the shade of the composite, and the curing light.

Question 43

Why is the depth of cure important?

Answer 43

If the composite near the pulp isn’t fully cured, it can cause pulpal irritation or postoperative sensitivity.

Question 44

How can you ensure proper curing of composite near the pulp?

Answer 44

Composite should be placed in thin layers to ensure full curing.

Question 45

What is incremental addition?

Answer 45

Incremental addition is the technique of placing composite in layers to ensure proper polymerization and minimize shrinkage.

Question 46

Why is incremental addition important?

Answer 46

Incremental addition ensures the composite shrinks less and is properly polymerized.

Question 47

Why is air inhibition helpful in composite placement?

Answer 47

Air inhibition helps each layer chemically bond to the previous layer, improving the restoration’s strength.

Question 48

What happens to C═C bonds during composite setting?

Answer 48

Not all C═C (carbon-carbon) bonds react; about 50% remain unreacted.

Question 49

Why is the presence of unreacted C═C bonds useful?

Answer 49

The unreacted C═C bonds allow the composite surface to be cleaned and repaired later by adding new material.