Irreversible Hydrocolloids

Irreversible Hydrocolloids

Describe the uses, advantages and disadvantages of irreversible hydrocolloid impression material.
Or
Explain in detail about irreversible hydrocolloids.
Answer:

Uses of Irreversible hydrocolloid impression:

• It is used for impression making
  • When there are undercuts
  • In the mouth with excessive flow of saliva
  • For partial denture with clasps.
• For making a preliminary impression for complete dentures.
• For impressions to make study models and working casts.
• For duplicating models

Advantages of Irreversible hydrocolloid impression:

• Easy to mix and manipulate.
• Minimum requirement of equipment.
• The flexibility of the set impression.
• Accuracy if properly handled.
• Low cost.
• Comfortable to the patients.
• It gives a good surface detail even in the presence of saliva.

Disadvantages of Irreversible hydrocolloid impression:

• Cannot be electroplated so metal dies are not possible.
• It cannot be corrected.
• Poor dimensional stability cannot be stored for the long time due to the syneresis and imbibitions.
• Poor tear strength.
• Silica particles in dust cause possible health hazards.