Dental Materials Flashcards
Alloy of Mercury with silver, copper, tin, and zinc.
Amalgam
Desirable features of Amalgam.
durable, comprehensive strength is similar to enamel, and relatively inexpensive.
Undesirable features of amalgam.
unattractive, high thermal conductivity, dimensionally unstable, delayed expansion if contaminated by saliva, requires tooth support, fracturable by excessive occlusion, susceptible to galvanism when new.
What reduces the rate of corrosion to amalgam?
Polishing
How are overhang formation avoided?
Using a properly placed band and wedge. Detect overhang with explorer.
How is polymerization typically activated?
Fiber-optic light
Steps to placing a sealant.
Pumice, rinse, isolate, etch, rinse, dry, apply, remove excess, and polymerize.
Most common filler particles of a composite?
Silicates, quartz, or glass.
What is added to a composite for radiopacity?
Barium or Strontium
This has an exothermic reaction on mixing (use cool glass slab).
Zinc phosphate cement
This binds to dentin and releases fluoride.
Glass ionomer cement
This is commonly used for temporary cementation. Orange solvent typically used to clean the contaminated instruments of this material.
Zinc Oxide Eugenol
What is Agar?
Reversible hydrocolloid, Undergoes a physical reaction only, and susceptible to imbibition and syneresis.
What is Alginate?
Irreversible hydrocolloid, undergoes a chemical reaction, and susceptible to imbibition and syneresis.
What is Elastomeric?
Fkexible material
What materials set by polymerization EXCEPT?
Hydrocolloid
What is superior to beta (plaster) as a material?
Alpha (stone)
What is used to make a orthodontic model?
Plaster
What is used to make a study model/working model?
Stone
What is used to make a crown and bridge die or model?
Improved stone or diestone
What modifies the working time?
Add borax to slow set, add potassium sulfate to accelerate set.
Used for cast restorative patterns
Inlay and casting wax
Useful in removable prosthetic procedures.
Baseplate wax
Useful to obtain occlusal records.
Bite registration wax
Used in pouring models
Boxing wax
Becomes sticky when heated, used to attach models.
Sticky Wax
Used to modify the shape of impression trays and cushion braces.
Utility Wax
What does precious alloys contain?
noble metals
What does non precious alloys contain?
Base metals
What can gold be polished with intra-orally?
Tin Oxide
What can gold be polished with extra-orally?
Rouge
What may prosthesis be?
cylindrical or have a blade shape.
What are implants?
Endosteal
Whats the leading cause of implant failure?
MOBILITY, lack of osseo-integration, and inadequate bone.
Contraindications to implant placement?
Inadequate bone, uncontrolled periodontal disease, smoking, infection, and biphosphonates.
Active ingredient in Tartar control toothpastes?
Pyrophosphate
Active ingredient in gum care toothpastes?
Triclosan (antimicrobial agent)
Active ingredient in desensitization toothpastes?
Potassium nitrate, sodium citrate, or strontium chloride.
Active ingredient in bleach or tooth-whitening?
Carbamide peroxide or hydrogen peroxide
