Week 5 Carving, Polishing, etc

Question 1

Polishing

Answer 1

involves the abrasion of a surface by an abrasive agent that is harder than the surface being abraded, or polished. The process of abrading the surface to reduce size of scratches and irregularities.

Question 2

Cutting

Answer 2

removing material by a shearing off process

Question 3

Abrasion

Answer 3

wearing away of a surface.

Question 4

Finishing

Answer 4

producing the final shape and contour of a
restoration.

Question 5

Abrasive

Answer 5

material used to wearing way a surface.

Question 6

Tribology

Answer 6

science of interacting surfaces in motion. Principles of friction, lubrication, and wear.

Question 7

Types of abrasives

Answer 7

▪Chalk
▪Pumice
▪Sand
▪Cuttle
▪Garnet
▪Emery
▪Silex
▪Tin oxide ▪Aluminum oxide

Question 8

Bonded and Coated Abrasives

Answer 8

▪Diamond burs
▪Stones
▪Rubber wheels or points ▪Rubber cups
▪Disks or strips ▪Powders

Question 9

Factors Affecting the Rate of Abrasion

Answer 9

▪Hardness ▪Size ▪Shape ▪Pressure ▪Speed ▪Lubrication
▪Care needs to be taken with softer materials and abrasive agents.

Question 10

Why polish

Answer 10

▪To reduce adhesion
▪To make the surface feel smooth ▪To increase esthetics
▪To reduce corrosion

Question 11

Abrasives used in dentifrices(toothpaste)

Answer 11

▪Phosphates ▪Carbonates
▪ Sodium bicarbonate ▪ Calcium carbonate
▪Silicas

Question 12

Micromechanical bonding

Answer 12

bonding using surface irregularities smaller than can be seen with the naked eye or felt with a explorer. Interlocking of surfaces. ACID ETCHING is this!

Question 13

Macromechanical bonding

Answer 13

the locking of two surfaces together using surface “roughness” and can be seen and/or felt.

Question 14

Chemical adhesion in dentistry

Answer 14

▪Polycarboxylate cements
▪Glass ionomer cements

Question 15

Adhesive failure

Answer 15

material breaks free from tooth, literally the adhesive material failed

Question 16

Cohesive failure

Answer 16

breakage with in the material. Material broke, not the bond.

Question 17

T or F Acid etching is used to bond material to the enamel not dentin.

Answer 17

true

Question 18

Etch acid typically used

Answer 18

Orthophosphoric acids at 37% is the most common used.

Question 19

How long to etch

Answer 19

15-30 seconds

Question 20

Three-step dentinal bonding systems

Answer 20

1. Etch dentin and enamel
2. Apply primer
3. Apply adhesive
4. Composite placement
5. Dentinal bonding adhesive mechanisms
6. Clinical research

Question 21

Hybrid layer composed of

Answer 21

resin and decalcified dentin

Question 22

Dental Cements uses

Answer 22

luting agents (crowns), pulp protection 2mm thick as a base, temp restoration, endo sealers or perio packs, cavity sealers

Question 23

Formulation of dental cements liquid/powder system

Answer 23

Liquid is an acid, powder is the base.

Question 24

Powders used in cements

Answer 24

zinc oxide, powdered glass (silicon oxide)

Question 25

Liquids Used in Dental Cements

Answer 25

▪Eugenol ▪Phosphoric acid ▪Polyacrylic acid

Question 26

Eugenol

Answer 26

Organic liquid – oil of cloves (distinct smell) Inhibits free-radical polymerization

Question 27

Phosphoric acid

Answer 27

▪Aqueous solution of approximately 2/3 phosphoric acid and 1/3 water

Question 28

Polyacrylic acid

Answer 28

▪Dispensing – does not form independent drops. Drops can run together. ▪Bonding – stable in a wet environment ▪Water-hardening cements – liquid is predominately water ▪Viscous liquids.

Question 29

How long does it take to mix temporary cement?

Answer 29

about 30 seconds, should be uniform in color, string between slab and spatula for correct consistency

Question 30

Zinc Phosphate cement precautions and tips

Answer 30

-do not cool the slab beyond the dew out, condensation will adversely affect the mix and setting time. -mix slowly in increments to dissipate heat -close the bottles to prevent absorption of moisture -Mix using a large area of slab to dissipate the heat. -clean the slab and spatula immediately

Question 31

Calcium hydroxide liner/base precautions and tips

Answer 31

humidity will accelerate the setting reaction. Mix until a homogeneous color, wipe mixing instrument clean with a gauze before applying material to cavity preparation.

Question 32

Glass Ionomer Cement precautions and tips

Answer 32

-should be used when the mix is glossy -when dispensing take the necessary time to make precise uniform drops -mixing time is short usually 45 seconds or less.

Question 33

ZOE precautions and tips

Answer 33

-If it's sticky and difficult to place, there is not enough powder incorporated. -Use firm pressure with the flat face of spatula when incorporating powder. -Enough powder has been incorporated for a base consistency when the mix "flakes" from the spatula pressing on the cement.

Question 34

Temporary Cement precautions

Answer 34

humidity will accelerate the setting of ZOE based materials, mix until homogenous color is obtained.

Question 35

If a tooth becomes contaminated after etching, you must re-etch for ____ seconds

Answer 35

5 seconds

Question 36

Dentinal bonding systems function by way of

Answer 36

micro mechanical bonding and secondary atomic bonds