Operative dentistry

Question 1

Enamel thickness for dogs and cats

Answer 1

Dog .3-.6mm
Cats .1-.3mm

Question 2

How many dentin tubules are present

Answer 2

JVD 2010- 75,000
Wiggs - 29,000-52,000

Question 3

What happens when dentinal tubules are exposed

Answer 3

Pain is caused by rapid outflow of fluid
Outward - cold
Inward - hot

Question 4

What is the difference between C and A delta fibers

Answer 4

A delta = myelinated, larger, rapid pain
C type = smaller, unmyelinated, slow dull pain

Question 5

What are the two types of tertiary dentin

Answer 5

Reactionary - formed from pre existing odontoblast
Reparative - formed from new odontoblasts due to death of original

Question 6

Tertiary dentin

Answer 6

Rapidly irregular deposited dentin

Question 7

Sclerotic dentin

Answer 7

Highly mineralized and occurs when odontoblasts are lost leaving a dead tract
Difficult to bond

Question 8

What are the 3 types of cavity classes

Answer 8

Simple - 1 tooth
Compound - 2 teeth
Complex - 3+ teeth

Question 9

Class 1 cavity

Answer 9

I,PM,M
Pit/fissure commonly found on occlusal surfaces

Question 10

Class 2 cavity

Answer 10

PM/M
Proximal surface of caudal teeth

Question 11

Class 3 Cavity

Answer 11

I/C
Proximal surfaces of rostral teeth without incisive involvement

Question 12

Class 4 cavity

Answer 12

I/C
proximal surface of rostral teeth with incisive involvement

Question 13

Class 5 cavity

Answer 13

I/C/PM/M
Gingival 3rd surface

Question 14

Class VI cavity

Answer 14

I/C/PM/M
defect of the incisal edge or cusp

Question 15

Stress vs Strain

Answer 15

Stress- When a force acts on a constrained body, the body resists the force.
Strain- is described as the change in length (ΔL = L − Lo) per original length (Lo) of the body when it is subjected to a load.

Question 16

Wetability and appropriate angle

Answer 16

Surface wettability, which is characterized by the contact angles of a water droplet on a solid surface, is used to describe the ability of a water droplet in maintaining contact with the solid surface. It is also used to indicate the water repellency of the surface.
Angle = 0

Question 17

Ideal properties of restoration

Answer 17

Good esthetics
Biocompatible
Not dissolve in oral fluids
Strength and modulus similar to tooth
Good abrasive/wear resistance
Coefficient of thermal expansion similar to tooth
Minimal dimensional changes with setting
High polishability
Radiopaque
Adhere to tooth structure

Question 18

Common restoration materials

Answer 18

*Composites
*Glass Ionomer Cements (GICs)
*Resin Modified Glass Ionomer Cements (RMGICs)
*Amalgam
*Compomers
*Giomers

Question 19

What are the four major components of composite resin

Answer 19

Inorganic filler - quartz/glass
Organic resins - glue
Coupling agent - link
Initiator - accelerator

Question 20

What is the main component of fillers

Answer 20

Quartz/silica
**increased amt of filler increases the strength and reduces polymerization

Question 21

CR organic resins are

Answer 21

Methacrylates
**Bisphenol A glycidyl methacrylate (bis-GMA)
**Triethylene glycol dimethacrylate (TEGDMA)
**Urethane dimethacrylate (UDMA)
Silorane
**epoxy

Question 22

What are the disadvantage of methacrylates

Answer 22

polymerization shrinkage
Micro-leakage

Question 23

Silane is commonly used for as?

Answer 23

Coupling agent

Question 24

What are the 3 types of initiator types

Answer 24

Chemical
Light activation
Dual (self/light)

Question 25

Benzoyl peroxide is what kind of initiator

Answer 25

chemical

Question 26

Camphoroquinone is what type of initiator

Answer 26

Visible light (460-480)

Question 27

Benzoin methyl ether is what type of initiator

Answer 27

UV light cured (365)

Question 28

What are the 6 types of composite classification

Answer 28

Macrofilled Microfilled Hybrid Nanofills Nanohybrid Flowable

Question 29

What type of composite is recommended for type III/V cavity restoration

Answer 29

Macro/micro

Question 30

What are the four types of fluoride releasing materials

Answer 30

**Resin composites--Better mechanical properties, wear, least fluoride **Conventional GI--Thermal expansion coefficient similar to tooth, lower wear resistance, high fluoride release **RMGI--Prone to abrasion, decreased flexural strength, should not be used in occlusal load-bearing areas **Compomers--More resin than RMGI Better mechanical properties like resin composites Moderate fluoride release

Question 31

Acid etch is made of what

Answer 31

phosphoric acid 35-38% 30 sec = enamel 15 sec = dentin

Question 32

What generation is etching required for bonding

Answer 32

4th = multiple bottle 5th = single bottle

Question 33

What generation of bonding does not require etch

Answer 33

6th = 2 bottle 7th = 1 bottle

Question 34

What are the 8 steps to cavity prep.

Answer 34

Outline form Resistance form Retention form Pathology removal form Wall Form Preparation cleansing form Margin placement Pulpal protection

Question 35

What class of cavity is amalgam recommended for

Answer 35

Class 1

Question 36

What type of restoration requires beveling

Answer 36

Class III-VI **not Class V if near CEJ

Question 37

What is the difference between ferrous and non-ferrous metal

Answer 37

Ferrous--iron/steel Non-Ferrous --Noble (gold, platinum, palladium, iridium, rhodium, ruthenium, and osmium)

Question 38

What is the difference between precious metals vs alloy

Answer 38

Precious = noble + silver Alloy = combination of several metals

Question 39

What is a luting agent

Answer 39

dental cement connecting the underlying tooth to a fixed prosthesis

Question 40

What is the difference between resistance and retention

Answer 40

**Retention- ability to be retained when subjected to tensile forces along the long axis of the tooth preparation **Resistance- ability to resist dislodgement when apical or oblique forces are applied

Question 41

Convergence angle PM4

Answer 41

43

Question 42

Convergence angle MN M1

Answer 42

36

Question 43

Ideal convergence angle

Answer 43

12

Question 44

Cast vs die

Answer 44

Cast - stone positive reproduction model involving large area of oral tissues Die - same as cast but only a single tooth is replicated

Question 45

What do liners do

Answer 45

zinc oxide or calcium hydroxide that can be applied to help protect the pulp **can use GIC, RMGIC