Properties Of Waxes Flashcards
Since wax is a mixture of different components they do not melt on a single temperature and do not have a melting point rather they have a melting range.
Melting range
The area of variation between upper and lower limits on a particular scale.
Range
If it’s lower end of the range, it?
Few components melt
If it’s the highest end of the range, it?
All components of wax will melt
Is highly dependent on temperature and time.
Flow
True or false.
For pattern wax flow is generally not desirable at room temperature since it results in a permanent distortion of the wax pattern.
True
True or false.
Waxes have the highest coefficient of thermal expansion of any dental materials. LCTE of typical pattern wax, 323 x 10 ^ -6 / ⁰C.
True
Is the stress remaining in a wax as a result of manipulation during heating cooling bending carving or other manipulation.
Residual stress
True or false.
The release of the residual stress at higher temperatures can cause an irreversible deformation that can destroy the fit of the wax pattern.
True
The time between finishing and investing the pattern should be minimized less than ________________because longer storage times allowed time stresses to be released.
30 minutes
Another thermal characteristics of inlay is their _______ coefficient of thermal expansion
High
True or false.
Inlay wax expands and contracts thermally more per degree temperature change than any other dental material.
True
The temperature at which a change in rate occurs is known as the?
Glass transition temperature
True or false.
Not all waxes exhibit transition temperatures.
True
True or false.
If the wax is allowed to cool without being placed under pressure, the transition temperature region is not as pronounced when it is reheated, nor is there much change in the thermal expansion coefficient.
True
