Water/Oil Based Cements Flashcards
What is a big advantage of polymer based cements over traditional water based cements?
polymer cements bond to tooth structure while water based do not
give some examples of traditional cements
- zinc oxide- eugenol (oil based)
- zinc phosphate (water based)
give some examples of polymer based cements
- polycarboxylate
- glass ionomer
- resin modified glass ionomer
- composite resin
give examples of temporary filling material
- ZOE
- silicophosphate
- glass ionomer
give examples of durable filling material
- glass ionomer
- silica
give examples of cavity liner or base
- ZOE
- glass ionomer
give examples of cementation
- all but silicate cement
Properties we want in cements
- low or no coefficient of thermal expansion
- low thermal conductivity
- compressive/tensile/bond strength
- insoluble
-adequate working time - short setting time
- resistance to dislodging forces
- adequate flow
- adhesive
- resist plastic deformation/high elastic modulus
- not sedative
- anticariogenic
-transluecent - thin film thickness
- non toxic
- easy to clean up
What is one of the most important properties of cements?
solubility
- don’t want it to be soluble because premature contact with water/saliva results in leaching of surface
What should be applied to vital tooth to avoid irreversible trauma to pulp?
calcium hydroxide or varnish
What is controlled by the operator affecting the rate of set of zinc phosphate cement:
- power/liquid ratio (more powder= faster)
- rate of power incorporation/mixing (faster mixing= faster)
- mixing temperature (increase temp= faster)
- manner of spatulation/mixing (faster mixing= faster)
Downsides of zinc phosphate cement:
- most rigid
- irritant (due to acidity)
- no adhesion
- no anti-bacterial properties
good because insoluble
Which cement is not used
zinc silicophosphate cement
What is often used at ULSD for temporary material?
zinc oxide eugenol
- temporary because soluble
In zinc oxide powder cement, what does rosin do?
reduce brittleness
In zinc oxide powder cement, what does zinc stearate do?
plasticizer
In zinc oxide powder cement, what does zinc acetate do?
increase strength and setting reaction
In zinc oxide liquid cement, what does olive oil do?
plasticizer
What was added to zinc oxide eogonel to try to make it less soluble and more of a permanent material? (didn’t work)
polymethyl methacrylate
Setting reaction of zinc oxide-eogonel
chelate rxn forming a ring as a result
Difference in powder/liquid ratio manipulation of zinc phosphate and zinc oxide:
- zinc phosphate: small quantities added at a time
- zinc oxide: large amount of powder can be added by heavy spatulation
Which requires a cool slab for mixing?
- zinc phosphates
- zinc polycarboxylate
Which material is so thick it makes the flow deceptive?
zinc oxides
Some properties of zinc oxide:
- long working/setting times
- low strength
- high solubility (won’t last longer than 6 weeks)
- good sealing properties
Which material is an obtundant material?
zinc oxide eugenol
Which material inhibits set of resin?
zinc oxide eugenol
Which material is very acidic and can cause irreversible trauma to pulp making it best to apply calcium hydroxide or varnish to vital dentin?
zinc phosphate
