What are the properties of dental materials?
Physical properties of Dental Materials are based on:
- The laws of mechanics-Creep & flow , abrasion and abrasion resistance , viscosity.
- Thermodynamics e.g. Thermal conductivity , Thermal diffusivity and Coefficient of thermal expansion.
Why is strength not a true property of brittle dental materials?
Plastic deformation occurs when the elastic stress limit (proportional limit) of the prosthesis material is exceeded. Thus, strength is not a true property of a material compared with fracture toughness, which more accurately describes the resistance to crack propagation of brittle materials.
What does viscosity mean in dentistry?
Viscosity. When a substance flows under the influence of an external force (e.g. gravity), the molecules or atoms come into contact with different neighbours. Thus, bonds must be broken and remade, and this gives rise to a resistance to flow, known as viscosity.
What is flow in dental materials?
FLOW The term flow is used in dentistry to describe the rheology of amorphous materials such as waxes. The flow of wax is its potential to deform under a small static load ,even that associated with its own mass.
What do you think is the importance of knowing the properties of dental materials?
If you know exactly which material has greater compressive strength and which is more likely to fracture under normal physiological masticatory forces, you can choose the material which has superior physical properties for restoration. This decreases the rates of failure of treatment.
What are dental materials?
Dental materials include the natural tissues (enamel, dentin, cementum, bone, and other intraoral tissues) and biocompatible synthetic materials (metals, ceramics, polymers, and composite structures) used to restore decayed, damaged, or fractured teeth.
Why is the knowledge of the properties of dental materials important in the practice of dentistry?
Key Terms. An understanding of the physical, electrical, and mechanical properties of materials used in dentistry is of tremendous importance. As a result, their properties are the basis for the selection of materials to be used in particular dental procedures and restorations.
What is viscosity and does it apply to both fluid and gas?
Viscosity is the resistance of a fluid (liquid or gas) to a change in shape or movement of neighbouring portions relative to one another. Viscosity denotes opposition to flow.
What is the principle of viscosity?
The principle of viscosity is stated here: When a layer of liquid is subjected to move upon a surface or another layer of the same liquid, the fluid particles tend to oppose such movement; this resisting force developed by a liquid is called viscosity.
What is setting expansion in dentistry?
Dental gypsum products when mixed with water and allowed to “set” in air exhibit an. expansion of their peripheral boundaries that is known as “normal setting expansion.” When additional water is brought into contact withthe setting material, an increased. expansion is observed.