5 Written questions
5 Matching questions
- Elastic modulus
- ___________represents the ability of a material to sustain a large permanent deformation under a <b>tensile</b> load before it fractures.
- Three types of stress in dentistry:
- Shear stress is calculated by dividing the force by the area ________ to the force direction.
- a 1. tensile stress
2. shear stress
3. compressive stress
- b Force per unit area within a structure subjected to an external force or pressure (See Pressure).
- c Relative stiffness of a material; ratio of elastic stress to elastic strain
- e b. parallel
brackets for braces is a good example
5 Multiple choice questions
- Plastic deformation occurs when the <b>elastic stress limit (proportional limit)</b> within the prosthesis is exceeded.
- Ratio of applied force to the actual cross-sectional area; however, for convenience stress is often calculated as the ratio of applied force to the initial cross-sectional area.
- 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.
- of enamel rod orientation.
- composites followed by porcelain, PMMA, amalgam and alumina.
5 True/False questions
Units of Modulus of elasticity → Giganewtons per square meter (GN/m²), or gigapascals (<b>GPa</b>)
Which is more stronger in tesnion?
b. dentin →
dentin → 50 MPa
enamel → 10 MPa
Maximum stress that is required to cause fracture is called _________. → Ultimate strength
From mechanical property point of view, why isn't it a good idea to burnish amalgam, composites, ceramics and nonresin luting agents? → Stress and/or strain
What does the straight line in the strain-stress curve represent? →
the region represents <b>reversible</b> elastic deformation, because the stress remains below the proportional limit.