Luting Agents Flashcards
What’s re the 3 types of luting agents?
Dental cement
GIC
Composite
Describe the mechanism of glass ionomer luting agents?
Ion exchange with calcium in enamel and dentine
Hydrogen bonding with collagen in dentine
Surface of restoration must be sandblasted for mechanical adhesion
What is the difference between GIC and RMGIC?
RMGIC also contains a hydrophilic monomer - HEMA
This is light cured - more rapid set
Some have dual cure - dark cure, REDOX reaction
What is a disadvantage of RMGIC?
HEMA is cytotoxic - important there is no unreacted monomer as this can damage the pulp
HEMA expands in wet environments - cannot be used to cement porcelain or posts as will cause the restoration/ root to crack
What material is used to bond indirect composite?
Composite luting agent
Use dual cure as light penetration through inlay is poor
How are porcelain restorations cemented in?
Porcelain treated with HF to etch the surface
Surface wetting agent applied (silane coupling agent)
Composite luting agent (use light cure if porcelain is thin)
How are non-precious metals cemented in?
Roughen surface of inlay via sandblasting
Metal bonding agent applied to make surface hydrophobic
Composite luting agent - dual cure as light penetration is poor
How are precious metals cemented in?
Need tin plate on fitting surface
What is used for temporary cement?
Zinc oxide eugenol - must completely remove eugenol as residual may interfere with setting of definitive luting agent.
