Alginate Impression Dental

Alginate Impression Dental

Write a short note on diatomaceous earth.
Answer:

Diatomaceous earth is filer in various dental impression materials such as alginate, agar, zinc oxide eugenol impression paste, and impression compound.

• Diatomaceous earth is composed of remains of minute planktonic algae that were deposited millions of years ago and whose skeletons become calcified.
• 60% Diatomaceous earth is added in the alginate powder to increase the stiffness as well as strength of alginate gel.
• It also provides a smooth texture and aids in the formation of a sol by dispersing alginate powder particles when mixed with water.
• When the powder in the alginate can is fluffed to break loose the particles, diatomaceous earth which is made up of fie porous silica particles will become airborne when the lid is removed.
• Long-term exp of inhalation of this diatomaceous earth which consists of porous fie silica particles can cause silicosis or pulmonary hypersensitivity.

Diatomaceous earth is also used in catalyst paste of zinc oxide eugenol impression material.

• Here it provides proper consistency of the mix.
• 0.3 to 0.5% diatomaceous earth act as a filer in agar and control viscosity, rigidity, and strength.
• 50% diatomaceous earth in impression compound acts as a filter and increases the strength, reduces flow at mouth temperature, and decreases coefficient of thermal expansion.
• Kieselguhr a form of diatomaceous earth is used as a mild abrasive and polishing agent.