Polyether rubber impression material

Question 1

base paste

Answer 1

• imine terminated polymer (polyether)
• a colloidal silica as a filler
• glycol ether or phthalate as a plasticizer

Question 2

accelerator

Answer 2

• alkyl aromatic sulfonate(initiates crosslink)
• colloidal silica as filler to form paste
• glycoether or phthalate

Question 3

setting rxn

Answer 3

• polyether + sulfonic ester -> cross linked rubber
• additional polymerization and no by product is formed
• cured by rxn between aziridine rings
• copolymer of ethylene oxide and tetrahydrofuran
• cross linking by cationic polymerization via imine end groups
• hydrophilic
• setting time 8.3 min
• mixing: 30 sec

Question 4

other characteristics

Answer 4

• dimension stability good
• decreased flexibilitiy
• hydrophilic
• tear strength 3000 gm.cm
• shelf life more than 2 years

Question 5

advantages

Answer 5

• short working and setting time
• proven accuracy
• adequate tear strength
• hydrophilic
• long shelf life
• less distortion on removal
• good dimensional stabilty

Question 6

disadvantages

Answer 6

• stiffness requires blocking of undercuts
• slightly more expensive
• multiple casts cannot be poured due to stiffness of material