5 Written Questions
5 Matching Questions
- Compressive strength
- The fracture toughness of dentin varies by a factor of 3 as a function:
- if stress/strain value is very small the materials are said to be:
- Shear strength
- Tensile strength for:
a. Dental porcelain
c. Resin-based composite
e. Alumnia ceramic
- a of enamel rod orientation.
- b flexible
The <b>maximum flexibility</b> is defined as the flexural strain that occurs when the material is stressed to its proportional limit.
- c Maximum shear stress at the point of fracture of a test specimen.
- d Compressive <b>stress</b> within a compression test specimen at the point of fracture.
note: compressive stress -Ratio of compressive force to cross-sectional area perpendicular to the axis of applied force.
- e a. Dental porcelain → 50-100 MPa
b. Amalgam → 27-55 MPa
c. Resin-based composite → 30-90 MPa
d. Poly → 60 MPa
e. Alumnia ceramic → 120 MPa
5 Multiple Choice Questions
- 1. Compressive strength
2. proportional limit
- Relative ability of a material to deform physically under a <b>tensile</b> stress before it fractures
the term resilience is associated with 'springiness'
- Because of the reduction in area, the force required to increase deformation actually decreases.
5 True/False Questions
Maximum stress that is required to cause fracture is called _________. → Toughness increases with increases in strength and ductility.
which tooth structure has the hgiher <b>propotional limit</b> and <b>modulus of elasticity</b>?
b. dentin → a. increases
although ductility of the metal ↓↓
Stress → Force per unit area within a structure subjected to an external force or pressure (See Pressure).
Change in length per unit initial length.
Units are in %
When a metal had been stressed beyond its proportional limit, the hardness and strength of the metal ________ at the area of deformation.
b. decreases →