WorksheetsWaxes Tutorial
Total questions: 14
Worksheet time: 13mins
Which of the following is true of residual stress?
Is developed in wax when it is cooled under stress
Results in a uniform dimensional change that can be compensated for in the casting process
Can be minimized by the manipulation of a wax at a temperature as high as is practical
Can cause warpage that increases at higher storage temperatures and during longer storage times
A pattern wax might be used to do which of the following?
Make a corrective impression
Form a mold around an impression
Form the general size and contour of a restoration
Casting waxes possess useful properties, such as which of the following?
Tackiness
No residue other than carbon
Minimum values of flow at mouth temperaturemperature
Specified values of coefficient of thermal expansion
Which of the following statements are true?
Boxing wax is used for forming a mold around an impression before a gypsum cast is poured
Utility wax must stick to itself
Utility wax is used to prevent sad and distortion of alginate impression
Sticky wax is used to assemble metallic or resin pieces in a fixed temporary position and is brittle at room temperature
Which of the following statements apply to bite-registration waxes?
They are used to articulate models of opposing quadrants accurately.
Formulations are made from carnauba wax.
The flow of these waxes at 37O C if from 5% to 80%.
These waxes may distort when removed from the mouth.
You are treating a patient on a hot day, and the office temperature is significantly higher than normal. You notice that when you use a wax bite record to mount cast on your articulator, the occlusal relationship is not correct. Which properties of wax were most likely to be responsible for this problem?
Described the techniques that can be used to limit the problems of residual-stress incorporation in wax?
Flow of dental wax increases as the temperature increases.
True
False
As wax is heated, a significant expansion occurs, but upon cooling, contraction occurs reversibly.
True
False
Warm temperatures and long storage times increase the possibility of release of residual stress in wax patterns.
True
False
The release of residual stresses in a wax pattern will result in distortion of the wax pattern.
True
False
During burnout of a wax pattern, it is essential that the wax decompose and leave no residue.
True
False
If a wax pattern cannot be invested promptly, readapt the margins before investing the pattern
True
False
Residual stresses in a wax pattern can be minimized by manipulating the wax at temperatures below room temperature.
True
False
