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Flashcards in Lecture 2 Deck (16)
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1
Q

Occlusal Forces - WHat is the max range of occlusal forces in the mouth?

A

200 - 3500N Forces on 1st & 2nd molars vary from 400-800N

2
Q

Are occlusal forces bigger in anterior or posterior teeth?

A

Posterior teeth obviously!

3
Q

What is the average force on the bicuspids, cuspids and incisors?

A

Bicuspids - 300 Cuspids (Canine) - 200 Incisors - 150

4
Q

What are 4 factors that effect occlusal forces?

A

-age -anatomic location -occlusal scheme -placement of dental prosthesis

5
Q

Define STRESS

A

Stress - when a force acts on a constrained body, the force is rested by the body and the internal reaction is equal in magnitude and opposite in direction to the applied external force is call stress

6
Q

What is the equation for Stress and why are stress and force not the same?

A

S = F/area Not the same because….?

7
Q

Name the 4 types of stress

A
  1. Axial (straight or compressive) 2. Shear (tearing or parallel) 3. Bending 4. Torsional The 2 basic types are axial and shear
8
Q

Define Tensional stress

A

2 sets of forces directed AWAY from each other (being pulled apart)

9
Q

Define Strain

A

Deformation in a body due to stress

10
Q

Define each label on the stress strain curve

A

A. = Proportional limit: deals with the proportionality of strain to stress in the structure

B = elastic limit (point to which material can be stretched but still return to normal)

C = Plastic limit (the point of no return)

D = Ultimate tensile strength

11
Q

What is Yield strength?

A

Y: a small defined amount of permanent deformation has occurred in the material

this amount of permanent strain is indicated as 0.2%

12
Q

Define Ultimate Strength

A

(UTS) Maximum stress a material can withstand before failure in tension

ALSO

(Ultimate Compressive Strength) (UCS)

Maximum stress a material can withstand in COMPRESSION before failure

13
Q

Define Fracture strength or fracture stress

A

Point at which material fractures

14
Q

Define Resilience

A

Resistance of a material to PERMANENT Deformation

15
Q

Define Toughness

A

Resistance to material to fracture

16
Q

Define bond strength

A

The max stress a material can withstand before failure in SHEAR or TENSILE strength