Polyether Dental Impression Materials: Properties and Uses

Polyether Dental Impression Materials

Elastic impression materials are based on a polyether polymer with a reactive aziridine ring. These materials stiffen in the presence of a catalyst through a cationic polymerization process.

Synonyms

• Polyether
• Polyether polymer
• Polyethers

Chemical Composition of Self-Curing Materials

• Base: Polyether groups (aziridines), silica (filler), and phthalate glycol (plasticizer).
• Catalyst: Alkyl sulfonate (reactor that generates the ring opening), silica (filler), phthalate glycol (plasticizer), and solvent (octyl phthalate).

Curing Chemical Composition

• Base: Polyether resin, urethane dimethacrylate, and silicon dioxide (filler).
• Initiator: Light-activated photoinitiator.

Chemical Reaction: Polyether (base) + Alkyl sulfonate (catalyst) = Polyether.

Commercial Presentation and Consistencies

Commercial Presentation: Paste-paste system.

Consistencies: Light, regular, regular + diluent, and heavy.

Handling Techniques and Timing

• Mixing Time: 30 to 45 seconds.
• Working Time:
  • Light (L): 2.5 min
  • Regular (R): 2 - 3 min
  • Regular + Diluent (R+D): 3 - 4 min
  • Heavy (P): 2.5 min
• Polymerization Time:
  • Light (L): 4.5 min
  • Regular (R): 3 - 4.5 min
  • Regular + Diluent (R+D): 4 - 5.5 min
  • Heavy (P): 4.5 min

Properties and Main Uses

Properties: Elastic recovery (98.9%), flexibility (2%), runoff (0.03), low tear resistance, and good dimensional stability. These materials are hydrophilic and thixotropic.

Main Uses: Fabricating impressions for crowns and fixed prostheses.

Secondary Uses and Clinical Considerations

Secondary Uses: Bite records.

Advantages

• Acceptable color and odor.
• Long shelf life.
• Good dimensional stability.
• Compatible with commercial trays.
• Allows for more than one model to be performed.
• Clean technology.
• Hydrophilic and thixotropic properties.
• Polymerization is not affected by latex gloves.

Disadvantages

• Low runoff.
• Least elastic of all elastomers.
• Limited flexibility after polymerization.
• Absorbs water under high humidity conditions.
• Unpleasant taste.
• Short working time.
• High cost.
• The catalyst can be irritating.

Impression Techniques

Used when high detail reproduction is required. Types include:

• Multiple Printing: Light consistency followed by heavy.
• Double Printing: Putty consistency followed by light.
• Monophasic Impression: Single-step putty and light.

Disinfection of the Impression

Profuse washing with water is required. Specific protocols include:

• Alginate: Sodium hypochlorite (0.5%).
• Mercaptan: Sodium hypochlorite (0.5%).
• Condensation Silicone: According to the manufacturer.
• Addition Silicone: Sodium hypochlorite (0.5%) or glutaraldehyde (2%).
• Polyether: Sodium hypochlorite (0.5%) or spraying with 2% glutaraldehyde.
• Final Step: Wash with tap water.