Van noort Flashcards
T/F isoprene is a geometric isomer?
T
What is GP a polymer of?
Isoprene (2 methyl 1,3-butadiene)
Which two forms can rubber exist as a result geometry?
Cis and trans
What is GP am isomer of?
Trans isoprene
What type of material is GP thermoplastic or thermosetting?
Is it thermoplastic
What temperature does GP soften?
60-65degrees
What temperature does GP melt at?
100 degrees
How should you disinfect GP?
Sodium hypochlorite 5%
T/F solvents can be used to help disinfect GP?
F solvents eg acetone and alcohol,shoud not be used on GP as it causes GP to swell and thus eventually it will return to its in swollen state and thus the apical seal,will then be lost
What effect does light have on GP?
Light causes GP to become oxidised and thus it becomes brittle
What should you check before you use GP?
Need to check their flexibility to ensure they have not become brittle
T/F GP is able to take up 2 transformations ?
T
At high temp when cooled rapidly the GP can form a crystalline beta structure
When cooled slowly it’s takes on and alpha form which is preferred for the heat systems
What other materials are available for root canal obturation?
Metal points
Gold, tin, lead, copper
What are the advantages of silver points?
They have a bactericidal effect
What were the disadvantages of using silver points?
Relies heavily on canal sealer
Corrosion products causes the apical tissue to discolour
Problematic to remove
