Dental Impression Materials

Impression Materials

Impression Compounds

• Type of impression material used for making impressions of the mouth
• Composed of wax, resins, and fillers
• Properties:
  • Thermoplastic (can be softened and molded repeatedly)
  • Low cost
  • Easy to use
• Indications:
  • Primary impressions for dentures
  • Border molding
  • impression trays

Alginate Impressions

• Type of impression material used for making impressions of teeth and surrounding tissues
• Composed of alginate powder and water
• Properties:
  • Fast setting (1-2 minutes)
  • Low cost
  • Easy to use
• Indications:
  • Routine impressions for crowns, bridges, and dentures
  • Preliminary impressions for orthodontic treatment

Polyether Impressions

• Type of impression material used for making impressions of teeth and surrounding tissues
• Composed of polyether resin and catalyst
• Properties:
  • High accuracy
  • High detail reproduction
  • Fast setting (2-3 minutes)
• Indications:
  • Impressions for crowns, bridges, and dentures
  • Impressions for implants and surgical guides

Impression Techniques

• Types of impression techniques:
  • Mucostatic technique: captures the soft tissue in its natural state
  • Mucodisplacive technique: displaces the soft tissue to capture the underlying bone
  • Selective pressure technique: combines mucostatic and mucodisplacive techniques
• Factors affecting impression accuracy:
  • Impression material properties
  • Tray design and fit
  • Patient factors (e.g. gag reflex, limited mouth opening)

Silicone Impressions

• Type of impression material used for making impressions of teeth and surrounding tissues
• Composed of silicone rubber and catalyst
• Properties:
  • High accuracy
  • High detail reproduction
  • Long working time
• Indications:
  • Impressions for crowns, bridges, and dentures
  • Impressions for implants and surgical guides
  • Border molding and custom tray fabrication

Impression Materials

• Impression compounds are used for making impressions of the mouth, composed of wax, resins, and fillers, and have properties like being thermoplastic, low-cost, and easy to use.
• Indications for impression compounds include primary impressions for dentures, border molding, and impression trays.

Alginate Impressions

• Alginate impressions are used for making impressions of teeth and surrounding tissues, composed of alginate powder and water, and have properties like fast setting (1-2 minutes), low cost, and easy to use.
• Indications for alginate impressions include routine impressions for crowns, bridges, and dentures, and preliminary impressions for orthodontic treatment.

Polyether Impressions

• Polyether impressions are used for making impressions of teeth and surrounding tissues, composed of polyether resin and catalyst, and have properties like high accuracy, high detail reproduction, and fast setting (2-3 minutes).
• Indications for polyether impressions include impressions for crowns, bridges, and dentures, and impressions for implants and surgical guides.

Impression Techniques

• Mucostatic technique captures the soft tissue in its natural state, while mucodisplacive technique displaces the soft tissue to capture the underlying bone.
• Selective pressure technique combines mucostatic and mucodisplacive techniques.
• Factors affecting impression accuracy include impression material properties, tray design and fit, and patient factors like gag reflex and limited mouth opening.

Silicone Impressions

• Silicone impressions are used for making impressions of teeth and surrounding tissues, composed of silicone rubber and catalyst, and have properties like high accuracy, high detail reproduction, and long working time.
• Indications for silicone impressions include impressions for crowns, bridges, and dentures, impressions for implants and surgical guides, and border molding and custom tray fabrication.