Materials Midterm Flashcards
Alloy
Combination of two or more metals
What material has been used for over 150 yrs
Amalgam
What type of restoration is glass ionomer used for
Primary teeth, final restorations in non stressed areas, sealants, core material for build ups, provisional restorations
IRM
Intermediate restorative material: short term restoration like zinc oxide Eugenol composition
Material that is still pliable when applied to teeth is what kind of restoration
Direct
Indirect restoration
A restoration fabricated outside the mouth by a lab tech
Where are indirect restorations made
In a lab
Liquids with high viscosity are not effective in what
Wetting a surface
Tensile stress
Pulls and stretches (tug of war)
Compressive stress
Pushes material together (chewing)
Shear stress
Sliding
How many mg are in a single capsule of amalgam
600 for small 800 for large
What type of restorations use amalgam
1,2,5 for direct
What is done with an amalgam capsule after mixing is complete
Placed in wide mouth airtight container labeled
Amalgamation
Mercury and alloy are mixed
How is curing time influenced for a composite restoration
Thickness and size of restoration, shade of material, manufacturers instructions
Advantage of using glass ionomer
Fluoride release, adhesion, resistance to acid erosion, strong, biocompatible with oral enviro, inhibits decay
Macrofilled composites
Conventional/traditional composite that contains large amounts of filler particles and provides strength
How many pounds per square inch does a posterior restoration need to withstand
170 pounds 28,000?
What metals make up alloy
Silver, zinc, tin, copper
What does silver do
Strength
What does tin do
Workability and strength
What does copper do
Strength and corrosion resistance
What does zinc do
Suppress oxidation
What is corrosion
Reaction that occurs within metal when exposed to temp, humidity, and saline
How is corrosion removed
Polishing agents
What is a non Mercury alloy
Galloy: composed of gallium, indium, and tin (gallium)
What is used to ensure accurate ratios of alloy and Mercury
Eames technique 1:1
What does properly triturated amalgam look like
Soft, pliable, and easily shaped
What type of cement used as adhesive for permanent indirect restorations
Type 1: luting agent (glass ionomer, ZOE, poly carboxylate, zinc phosphate)
How should cements be dispensed when there is powder to liquid involved
Powder and liquid on opposite sides, In increments, smallest first
When would u use temp cement
When u need temp coverage until perm restoration is ready or patient is in pain and something is needed
What might happen if there is a delay in mixing and placing of indirect restoration
Result in initial setting process causing casting to not seat right
What cement gives of exothermic heat
Zinc phosphate
How is cement placed in an indirect restoration for delivery
Line surface
What kind of cement is less sensitive to the pulp than zinc phosphate
Polycarboxlyate
Which type of glass ionomer is used to restore areas or erosion near gingiva
Type 2
Which type of cement would be used for cement action of ceramic veneers
Composite resin
What can occur if cement is left around margins of the crown
Cement can irritate the area and cause inflammation and discomfort
What can influence cementation procedure
Mixing time, humidity, powder to liquid ratio, temp
What should a provisional restoration be filled with when being placed for temp coverage
Luting cement
How does polycarboxlyate appear once setting has initiated
Loss of glossiness is stringy or weblike
If more time is needed for mixing of a cement what can be used
A glass slab
What cement is irritating to the pulp and most acidic
Zinc phosphate
What is an impression
Negative reproduction of the mouth
What material used first with elastomeric impression
Light bodied
3 classifications of impressions
Preliminary, final, occlusal (bite registration)
What is made from preliminary impression
diagnostic models, custom trays, provisional coverage, orthodontic appliances, pretreatment/post treatment records
How much material should fit between tray and edges of teeth
2-3mm
What does an impression become after poured in plaster
A positive
What irreversible hydrocolloid is used most widely for preliminary impressions
Alginate
How quickly should alignate impression be poured up
Within 1 hour of taking impression
Imbibition
Absorption of water causing object to swell
Syneresis
Loss of water causing to shrink
How do u alter setting time of irreversible alignate
Using cool water
What is the elastomeric material with highest viscosity
Putty
What can an automix system for elastomeric impression material do
Automatically mixes and dispenses used with light and heavy body
3 curing stages for impression materials
Initial set, final set, final cure
How does water affect alignate impression mix
Alter setting time
What is the most viscous reversible hydrocolloid
Tray material/heavy bodied
3 classifications for impression materials
Irreversible and reversible hydrocolloid and elastomeric
