Dental Materials 1 & 2

Front 1

What does ANSI?

Back 1

The American Standards Institute: it manages and coordinates the development of standards in many disciplines including dentistry

Front 2

What does the ADA Council of Scientific Affairs (CSA) do?

Back 2

Oversees Accredited Standards committee (ASC) MD 156 of ANSI which writes specifications

Front 3

Where do international standards and regulations come from?

Back 3

FDI: dental, ISO: professional, and regulatory depends on the country

Front 4

What type of program is the ASA seal of acceptance?

Back 4

A consumer goods program, the ADA no longer maintains Seal program for professional products

Front 5

What does the ADA professional product review do?

Back 5

Evaluates materials instruments and devices

Front 6

Which organization has the authority to protect the public from hazardous and/or ineffective medical devices?

Back 6

The FDA

Front 7

What type of product is FDA class 1 and what regulations go with marketing it?

Back 7

Products poses least risk to health (dental floss, cotton rolls and burs) Manufacturer must register products, adhere to good manufacturing procedures and meet record keeping requirements.

Front 8

What type of product is FDA class 2 and what standards must these products meet?

Back 8

Products have higher risk to health (dental needles, alloys and amalgam) Must meet FDA or ADA specifications.

Front 9

What Products are FDA class 3 and what is required before marketing?

Back 9

Life sustaining or presenting potential unreasonable risks of illness or injury (dental implants and lasers) Approval for safety and effectiveness is required before marketing

Front 10

What organization is responsible for international standards and which advisory group to this organization is sponsored by the ADA?

Back 10

ISO, ISO/TC 106

Front 11

Which agency requires that the MSDS be kept for all dental materials?

Back 11

OSHA

Front 12

How does the EPA get evolved in dentistry?

Back 12

All by-products of dental procedures end up as solid, liquid or gaseous waste and their disposal can be regulated by the EPA.

Front 13

What are some publications that evaluate Dental Material?

Back 13

Clinicians Report, Dental Advisor, USAF dental evaluation & consultation service (DECS), Professional Product Review, Reality-the information source for esthetic dentistry,

Front 14

What are the three types of primary bonding?

Back 14

Ionic bonding, Covalent bonding and Metallic bonding

Front 15

Which electrons primarily control the relationship between atoms?

Back 15

The valence or outer electrons

Front 16

How do atoms that make up a substance determine its properties?

Back 16

By both their nature and arrangement

Front 17

Which type of bonding is the basis for the formation of a crystal lattice structure?

Back 17

Ionic Bonding

Front 18

Ionic bonding is the basis of which materials?

Back 18

Ceramics

Front 19

Covalent Bonding of which element forms long chains called polymers?

Back 19

Carbon

Front 20

Why can polymers be useful solids?

Back 20

1) secondary valence forces are high 2) molecules are long and entangled, movement is restricted favoring existence as a solid

Front 21

What metallic properties come about because of metallic bonding?

Back 21

Thermal conductivity, electrical conductivity and luster

Front 22

What causes secondary bonding?

Back 22

Attractive interaction between molecules that are electrostatically unbalanced

Front 23

What types of Van der Waals forces were discussed?

Back 23

Permanent dipoles, Induced dipoles, and Instantaneous dipoles (London forces)

Front 24

What is the relative strength of bonds from greatest to weakest?

Back 24

Ionic bonds> Hydrogen bonds> Dipole-dipole> London forces

Front 25

What is chelation?

Back 25

When a chemical compound has bonds emanating from two places in the molecule toward a single atom. These bonds can be secondary, primary or a combo.

Front 26

What is the equilibrium distance?

Back 26

Where the attractive forces balance the repulsive forces at a certain distance between bonded atoms.

Front 27

Why do atoms resist compression stresses and tensile stresses?

Back 27

They resist compression because they must overcome the repulsive forces and they resist tensile stress because they must overcome attractive forces.

Front 28

Are materials generally stronger in compression or tension?

Back 28

Compression with a steeper energy distance curve.

Front 29

What might be indicated by a steeper energy distance curve?

Back 29

Higher modulus of elasticity or stiffness, Higher melting point, and lower coefficient for thermal expansion and smaller deformation for a given amount of applied force.

Front 30

What types of bonds are normally found in materials that are harder and more abrasive?

Back 30

Covalent and ionic bonds.

Front 31

What type of bonding might be found in soft lubricating materials?

Back 31

Secondary/ Vander Waal’s forces they may have strong covalent bonds but are characterized by the secondary bonds.

Front 32

What controls the states of matter?

Back 32

The strength of the interatomic bonds in relationship to the temp.

Front 33

What types of material exhibit an amorphous arrangement of atoms?

Back 33

Wax, Polymers, liquids, and glasses.

Front 34

What cause the space shuttle to explode?

Back 34

The o-rings were cold and so they didn’t provide a good seal and leaked fuel that exploded.

Front 35

What do material properties describe?

Back 35

The behavior of materials in storage, handling, physical, and mechanical application.

Front 36

What do mechanical properties refer to?

Back 36

The response of a material to force

Front 37

What is stress?

Back 37

A material’s resistance to an applied force. Force/Area

Front 38

What is the average biting force?

Back 38

150 lbs.

Front 39

How can biting on a small item fracture a tooth or other materials?

Back 39

Because when the 150 psi is distributed over a small area, the stress may reach 1,500,000 psi in that small area.

Front 40

What is tensile stress?

Back 40

Two forces acting in the same line, but directed away from eachother.

Front 41

What is compression?

Back 41

Two forces acting on a body in the same line directed towards each other.

Front 42

What is Shear?

Back 42

Two forces towards each other, but not in the same line

Front 43

Name 3 types of complex forces?

Back 43

Rotation, flexion, and Diametral tension

Front 44

How do you define Strain?

Back 44

The measure of the amount of deformation due to an applied force. Calculated as Change in length/ Original Length.

Front 45

How do you differentiate elastic strain from plastic strain?

Back 45

If permanent deformation has occurred then it is plastic strain.

Front 46

What is the proportional limit?

Back 46

It is the point on the Stress and Strain curve that represents the maximum stress at which a linear relationship between stress and strain is valid. Prediction is difficult beyond this point. This is considered to be the strength of a material.

Front 47

What is the elastic limit?

Back 47

The amount of stress a material can take w/out permanent deformation

Front 48

What is the yield strength?

Back 48

The stress at which as small amount of permanent strain occurs.

Front 49

What do we call the maximum stress obtained, based on the original dimensions of the object?

Back 49

Ultimate Strength

Front 50

What is the Breaking or Fracture strength?

Back 50

It is the stress at fracture based on original dimensions.

Front 51

What is modulus of elasticity and how is it calculated?

Back 51

Also called Youngs modulus it is the stiffness of a material within the elastic range and is calculated by Stress/Strain

Front 52

What does a high modulus indicate?

Back 52

A stiff material where high stress = small amount of strain.

Front 53

What is ductility?

Back 53

The ability of a material to withstand permanent deformation under tensile load w/out fracturing.

Front 54

How is ductility measured?

Back 54

% elongation or Increase in Length/ Original Length. Gold has a very high % elongation and the more pure, the higher it is.

Front 55

What is malleability?

Back 55

The ability of a material to withstand permanent deformation under pressure

Front 56

What is flexibility?

Back 56

The magnitude of stain at the elastic limit

Front 57

What is resilience?

Back 57

The resistance to permanent deformation and the area of the Stress-Strain curve up to the proportional limit.

Front 58

What does the area under the entire stress-stain curve up to the breaking point represent?

Back 58

Toughness

Front 59

Arrange the following from highest modulus of elasticity to lowest (stiffest to least stiff) Porcelain, Enamel, Gold, Dentin, Resin Composite, Cobalt-Chromium partial denture alloy

Back 59

1. The denture alloy 2. Gold 3.Enamel 4. Porcelain 5. Amalgam 6. Dentin 7. Resin Composite