Mechanical Properties Of Dental Materials

Mechanical Properties Of Dental Materials

Write a short note on flexibility and resilience.
Answer:

Flexibility:

• Generally in dental practice, the material used as a restoration should withstand high stresses and show
• minimum deformation. However, there are instances where a large strain is needed with moderate or slight stress.
• For example, in an orthodontic appliance, a spring is often bent a large distance with a small stress. In such a case material is said to be “flexible”.
• The “minimum flexibility” is designed as the strain that occurs when the material is stressed to its proportional limit.

Resilience:

• The term ‘resilience’ is associated with “springiness.” Resilience can be designed as the amount of energy absorbed by a structure when it is stressed not to exceed its proportional limit.
• For example, when an acrobat falls on a trapeze net, the energy of his fall is absorbed by the resilience of the net, and when this energy is released. The acrobat is again thrown into the air.
• The resilience of a material is usually measured in terms of its modulus of resilience which is the amount of energy stored in a body, when one unit volume of a material is stressed to its proportional limit.
• Resilience is also measured by the area under the straight line portion of the stress-strain curve.