Dr Fawy 20/08/2019 Flashcards
How does the setting reaction take place in indirect coronal restorations?
Polymerization via chemical activation, light activation, or dual activation.
What are the types of resin cement preparations?
Powder/liquid (Unlikely to encounter): Chemical light or dual cure
2paste system (Base and catalyst): Chemical, light, or dual cure
Single paste which is light cured
What do automixer tubes do?
Some automixer tubes at the tip of the syringe which automatically mixes 2 chemicals together to form the cement that can set.
What are the components of the bonding systems used for indirect restorations?
Bond with tooth surface by enamel and dentine bonding system (mostly micromechanical through interlocking of the resin with the tooth surface)
Bond with metal using metal primer
Bond with ceramic restoration by treating the surface of porcelain with silane coupling agent.
What is a metal primer?
Allows bonding to metal.
What do silane coupling agents do?
A chemical compound which operates with 2 “hands” one functional group can bind to ceramic and the other can bond to resin.
They are bifunctional, can bond to hydroxyl group on silica and the monomer of the resin cement.
What is the order of bond application?
Acid etch the tooth surface, then apply the resin, then apply the bonding agent.
What is Self Adhesive Resin Cements?
Self adhesive Resin Cements (SAC) can come in capsules or automixing syringes and claim no need for preconditioning the tooth structure.
More research needs to be done to test how effective it is compared to other traditional methods.
What do Self Adhesive Resin Cements do?
All resin cements whether adhesive or non-adhesive contain some level of micromechanical bonding.
What is a dentine primer?
Dentin bonding agent
What is ceramic composed of?
A silica (next lecture more info)
What is a metal primer?
Bifunctional coupling agent. One end carries methacryl for resin bonding and the other a mercapto group for bonding to precious metals.
How important is the step of applying bonding agent to a restoration?
Airing out the bonding agent has a huge impact on the bonding of the composite to tooth structure. Very controversial how it should be done.
