Acid etch and bonding Flashcards
Why don’t you want to over etch?
No etching pattern
Acid etch for enamel margins- creates what?
Increases wetting
What happens to the resin in relation to the canals?
The resin flows down the canals and locks in?
How far can resin penetrate the tubules?
Not as far as the etch does
What is dentine covered by?
A smear layer
What is the bonding agent made up of?
Methacrylate ensuring the bond with composite
What is a problem they had to over come with dentine bonding?
Dentine is hydrophilliic and bonding agents are hydrophobic due to enamel being hydrophobic.
What does dentine conditioners do?
Removes the smear layer
Opens the dentine tubules
Acid base reactions with hydroxyapatite
What do primers do?
Act as ahesives
Bond hydrophobic components to hydrophillic dentine
What does the solvent do?
Enhanced penetration by seeking and displacing water and coupling agent
M-R-X what are each ?
Methacrylate
Spacer molecule
Active component
Why apply a little air after prime?
Prevent evaporation
Why should you dry after etch?
Enable hydrophobic resin to penetrate and attach
What factors effect etching?
Time
Washing- removes debris
Drying- penetration and attachment
