Dental Waxes
Dental wax can be defined as a thermoplastic molding material that is solid at room temperature and when subjected to moderate temperatures becomes a low viscosity liquid.
“Role Of Thermal Expansion In Dental Wax Properties”
Composition of Dental Wax:
“Best Ways To Understand Dental Wax Composition”
Application of Dental Wax:
- Used in the formation of inlay patterns.
- Used in a dental laboratory to box impressions prior to cast pouring with gypsum.
- Used as a base plate for registration of jaw relation.
- Used as a casting wax to establish minimum thickness to certain areas.
- Used as a utility wax to prevent distortion of impression materials.
- Used as a sticky wax to join fractured parts together.
- Used as a corrective impression wax to contact and register the detail of soft tissue.
- Used as a bite registration wax.
Properties of Dental Wax:
- Melting Range:
- Waxes have melting ranges rather than melting points. Mixing of waxes may change their melting range. The melting range varies depending on its use.
- Thermal Expansion: Waxes expand when subjected to a rise in temperature and contract as the temperature is decreased. Dental waxes and their components have the largest coefficient of thermal expansion among the materials used in restorative dentistry. Temperature changes in wax patterns after removal from the mouth can produce inaccuracies in the finished restoration.
“Importance Of Dental Waxes In Prosthodontics”
- Mechanical Properties: The elastic modulus, proportional limit, and compressive strength of waxes are low compared to other dental materials. These properties are strongly dependent on the temperature. As temperature decreases, the properties improve.
- Flow: Flow is an important property, especially in inlay waxes. When melted, the wax should flow readily into all the parts of the die.
- Flow is dependent on:
- The temperature of the wax
- Force applied
- The length of time the force is applied.
- Flow increases as the melting point of the wax is approached.
- Residual Stress: Regardless of the method used to make a wax pattern, residual stresses will exist in the completed pattern. The stress may be compressive or tensile in nature.
- Ductility: Like flow, the ductility increases as the temperature of the wax is increased. In general, waxes with low melting points have greater ductility than those with high melting points
“Risk Factors For Failure Of Dental Waxes In Applications”
Dental Wax
Dental Wax Importance
- Their most important uses are as patterns, which are used to shape the molds in which resin and cast metal restorations are made.
- Dental waxes are important in the construction of dental prosthetic appliances.
Ideal Requirements of Dental Wax:
- When soften the wax should be uniform.
- The color should be contrasted with the die.
- There should be no flakiness, or roughening of the surface when the wax is molded after softening.
- The wax should not pull or chip during carving.
- During burnout (500°C), it should vaporize completely without residue.
“Early Signs Of Problems With Dental Wax Performance”
- The wax pattern should be rigid and dimensionally stable till it is eliminated.
- Dental Wax is sufficiently plastic slightly above the mouth temperature and gets rigid when cooled to mouth temperature.
- Wax should have good flow when heated and it set rigidly when cooled.
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